# CNC Clock Build W.I.P.



## J-G (10 Sep 2020)

Last week I responded to the thread asking if anyone was using CNC. The OP responded and suggested that W.I.P. could be interesting. I haven't done one previously and do understand that it might add to the time taken due to the need to take photo's and actually do a write-up.

I have however, done some groundwork and only yesterday made the first component - well a first attempt - so attached is a .PDF detailing how the project started and what has happened up to now.

Comments, Critique and Criticisms are all very welcome.


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## Alpha-Dave (10 Sep 2020)

Very interesting, thank you. As a basic CNC user I agree with you following points:
“Using CNC I’ve already found that it is wise to prepare the basic materials to closely prescribed dimensions and position the blanks accurately on the Router Table”. This setup stage is something that requires significant thought and preparation to get something right on the first try.


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## J-G (12 Sep 2020)

Second Installment attached. Not a great deal further forward as far as making components is concerned but a massive leap forward in understanding speeds/feeds & tooling.


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## J-G (18 Sep 2020)

Third - and probably last - installment attached. No, the project is no where near complete but there seems little interest with only 8 views of the second installment and only one comment from 103 views of the thread.


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## Trainee neophyte (18 Sep 2020)

Somehow I managed a double post, so I will delete the text of this one and recycle it. Firstly, the level of precision here fills me with dread. I can't cut accurate mortices - I couldn't begin to understand how all these components fit together. Probably part of the facination is to look at something beyond my comprehension. The fact that you just drew all the parts required on the computer rather assumes you know clock mechanisms inside out. I view them as magic, because I have no idea how it all works.

I really don't want you to stop this WIP, but I am just not qualified to make any coherent comments. Would you mind if I just watch from afar, with much awe and monkey head scratching? 

(Oh, and pdf no.3 appears to be identical to pdf no.2 - these things happen...)


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## MikeG. (18 Sep 2020)

Personally, I'd love to see images of the clock being made, but I'm not going to be opening PDFs. Why not just post photos like everyone else?


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## Bod (18 Sep 2020)

Photos would be good.

Bod


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## J-G (18 Sep 2020)

Thanks for that feedback MikeG - I did consider that the .PDF route might be a 'bridge too far' but the way I work is to write it up on-the-fly - that way I can report the 'issues' (read 'cock-ups') that come to light before I forget why they happened. I could try to turn the .PDF into a .PNG and see how that appears on the forum??? Another approach might be to 'copy and paste' the write-up text directly into a forum post and attach the images, though that may fall foul of the restriction on the number of attachments..... I'll do some tests..... It would also destroy the 'Graphic Design' but I can put up with that if it were considered more appealing and reach a wider audience.

@*Trainee neophyte *- you're too kind in your comments! Yes I have studied clock mechanisms ever since I became fascinated by seeing an Orrery when I was ~11 and being annoyed that it wasn't 'to scale'  but I'm by no means proficient*. *There's nothing 'Magic' about the basic concepts of gear ratios and converting a pendulum swing of one second into a display of hours and minutes - it's just arithmetic. 

As far as 'accuracy' is concerned, that is mostly down to being computer controlled. I doubt that I could make a good job of cutting a dovetail joint that would pass muster if I didn't have a suitable cutter for my milling machine  I'll concede that a lifetime of _thinking_ in terms of precision has a bearing though!

I've checked WIP-3.PDF by downloading it and it is the correct file - it's a single page whereas WIP-2 is 2 pages. Converting to .PNG I notice that I'd missed off the [Fig-N°]s so they've been added.


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## J-G (18 Sep 2020)

Well that looks 'OK' and I see that it can be viewed at an enlarged size so is still readable!

I've now converted the first two installments to .PNG (total 4 pages) so let's see if they are acceptable... They have all been attached so hopefully MikeG can see what's been done so far


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## donwatson (18 Sep 2020)

Thanks for this JG. I have downloaded but not had a look at the yet.
I am on this forum regularly and this is the first time I have seen this post. Can the moderators have any ideas on why it was not visible to me ? or am I just useless at using forums.
I will be back when I have had a look at the files.
Don W


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## MikeG. (18 Sep 2020)

Well, I can read that OK, and thanks for doing the conversion. I'm really not sure why you'd go to all the trouble with all the formatting and so on, rather than just write your text directly into the forum in a text box, inserting pictures at the appropriate places. It's the way everyone else does it.


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## J-G (19 Sep 2020)

You're welcome Mike. Creating a formatted page is natural to me as I've been accustomed to preparing text/images for Theatre Programmes and the like. As I've said, I write-up as and when I have a break from the workshop. Today I've added to a page at least 8 times over a period of 16 hours. I suppose that keeping a part completed post open all day wouldn't be a problem but with my current method I can at least [Save] the file as and when I go back to the real work 

Installment 4 attached.


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## Yojevol (19 Sep 2020)

J-G said:


> You're welcome Mike. Creating a formatted page is natural to me as I've been accustomed to preparing text/images for Theatre Programmes and the like. As I've said, I write-up as and when I have a break from the workshop. Today I've added to a page at least 8 times over a period of 16 hours. I suppose that keeping a part completed post open all day wouldn't be a problem but with my current method I can at least [Save] the file as and when I go back to the real work
> 
> Installment 4 attached.


When I do a lengthy post I compose it offline and simply copy and paste it into my post when complete. 
I started this in the old system as I lost some work being unfamiliar with the Save Draft facility. The new software is much better. I tested it yesterday by starting a post then I shut everything down. I was pleased to find it still there after rebooting. 
Brian


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## J-G (19 Sep 2020)

Thanks for that Brian. Much of my reticence is due to my lack of experience on the forum and my familiarity with CorelDRAW! - a bit 'old dog and new tricks' I suppose.


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## Yojevol (19 Sep 2020)

J-G said:


> Thanks for that Brian. Much of my reticence is due to my lack of experience on the forum and my familiarity with CorelDRAW! - a bit 'old dog and new tricks' I suppose.


I know the feeling. Another good reason for posting directly into the system is that it makes life much easier for others to comment and ask questions which is a major aspect of the Forum. 
Being a fellow traveller in the esoteric world of wooden clocks, with aspirations to go CNC, I might well be asking a few Q's myself. 
Brian


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## donwatson (19 Sep 2020)

Thanks for the WIP JG. I understand some of the problems and fixes that you have encountered. This seems a very difficult operation to make wooden clocks and I think maybe the reason I had no great success. I will stay with this WIP as you seem capable of solving the majority of the problems I met.
Don W


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## J-G (20 Sep 2020)

Quite a bit done over the last two days -- well a lot of time spent but not a lot of product made, just fiddly small components, but the Pendulum Pivot has been proved to 'Swing'. Fifth installment (in two parts) attached as is a short Video.





Your browser is not able to display this video.


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## donwatson (21 Sep 2020)

Thanks for these JG


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## J-G (24 Sep 2020)

I've finally beaten the Latch into submission so here is installment 6


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## donwatson (26 Sep 2020)

Thanks again JG


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## J-G (27 Sep 2020)

Have you learned anything Don? - or have any suggestions regarding my methods?


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## Cabinetman (27 Sep 2020)

As Don Watson said, I hadn’t seen this before either, strange. So another wooden clock man, well Mr Harrison became rather famous doing it and won the prize for calculating latitude or was it longitude back in the day. And he came from not far from me here. 
As the neophyte said totally beyond me but I’m referring to the CNC bit, I can imagine it’s probably the only way to make Clock parts accurately enough, mind you Mr Harrison managed it ha ha. Ian


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## J-G (27 Sep 2020)

Cabinetman said:


> As Don Watson said, I hadn’t seen this before either, strange. So another wooden clock man, well Mr Harrison became rather famous doing it and won the prize for calculating latitude or was it longitude back in the day. And he came from not far from me here.
> As the neophyte said totally beyond me but I’m referring to the CNC bit, I can imagine it’s probably the only way to make Clock parts accurately enough, mind you Mr Harrison managed it ha ha. Ian


*Longitude* it was Ian - thanks for your response though  

There have been many superb craftsmen who have done a much better job than I can achieve without the benefit of CNC. I have been inspired by Giovanni De Dondi who built a 7 faced clock over 16 years starting about 1348. This showed not only the time but the position of all the known planets. He even accounted for the apprent retrograde motion of Mercury buy incorporating an elliptical gear! He didn't even have access to gear cutting or threading equipment - all done by hand - one of his gears had 157 teeth, a prime number, cut by hand with a file! _ (Which he probably made himself)_

Then there is the _Antikythera mechanism_ ....... 1st century BC


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## donwatson (27 Sep 2020)

Thanks JG, I am intrigued by the way you have gone about making these pieces and am too much of an amateur to advise anyone on the use of the CNC router/milling machine


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## J-G (28 Sep 2020)

I've had a few problems over the past couple of days but I have another two pages done. Much of what is in these is a thought process - working through methodologies of multi-components and work-holding - and there's still a great deal to be done, but I have learned a lot about how different the CNC workflow is compared to piecemeal machining.


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## J-G (28 Sep 2020)

I've been reviewing the number of [Views] of the attachments and see that the .PDFs seem to be read more than the .PNG files so I've now created .PDFs of installments 4 to 7. I also think that the .PDFs are better quality and easier to read.


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## donwatson (28 Sep 2020)

Thanks again JG. I find the PDF a good choice as I only need to click on it and it downloads straight into my Downloads box.
I will go and have a look at the latest you have posted, all very fascinating stuff.


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## J-G (28 Sep 2020)

Thanks for that feedback Don. 
I'm also considering the 'Copy & Paste' direct into the Forum as suggested by MikeG as well.


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## J-G (29 Sep 2020)

Installment 8 attached as both a .PNG and a .PDF.


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## donwatson (30 Sep 2020)

Thanks JG. Will peruse this later


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## J-G (3 Oct 2020)

I've created another installment as a .PDF and two .PNG files which I will attach but I'll see what I can do as far as posting the text directly into the forum (Copy & Paste) and insert the images ...................

30th Sept
All seemed to be going well after I’d checked the proximity of the fly cutter to the clamps and finally pushed the [GO] button to skim the surface. I was quite pleased that the blank ‘off the saw’ was 7mm ± 0.2mm and the skimming produced a very good clean face. Doubts began to appear when drilling the pivot holes, some looked to be too close to the front edge and were increased when the first outline cuts didn’t clean up the front edge.

Even with what I thought was careful positioning, the blank was still about 1mm too far back. It was then interesting to see how CamBam had ordered the machining, starting at the left hand end, taking two cuts on the first two Pawls before starting on the 3rd and 4th, returning to the 1st two and so on. I wasn’t too concerned when the first Pawl broke away but when the second not only broke away but also broke across the middle - - - - - - -

The upshot is that I now think that African Blackwood is not the best choice for this component. Yes. it’s hard and will wear well but it seems it is also too brittle. Previously I’ve only used it in ‘slab’ form for the sides of boxes or knobs where, although open grained, is does take a very good finish when ‘filled - sealed and waxed’.

Fig-42 shows the results of this mornings disaster and I’ll now look at my stock of Beech to see if I can do a better job with that.




Not only that, I collected my Brass & Stainless Steel order and after a 20 minute drive home, found that they had supplied a length of 7mm Ø rather than 8mm !!

1st Oct
New layout sorted with just 6 Pawls and two Beech blanks created. I’d decided that I didn’t need a 3mm cutter to cut out the rough outline so designed this batch to use a 1.5mm end-mill. Quickly found out that a 1mm cut at 300mm/min was too much since on the second pass the tool broke - at least that’s the first breakage I’ve had. Changed the G-Code to have 0.5mm depth of cut and 150mm/min feed rate. Took a while to complete but I do have 6 Pawls in Beech which are useable. The second batch are now being machined.

The second Op. went without incident and all 12 Pawls are finished and Fig-43 shows 3 roughly in position around the Ratchet.




It will be a while before I have the part with the Pivot and retaining pins done as that is a 72 tooth Gear which has to be cut from a composite piece of Maple and I haven’t yet even looked at how I’m going to create the blank, never mind cutting the teeth. Though neither should be onerous, just time consuming.

I have made a start on some other components to while away the time taken for the G-Code to run its course.

2nd Oct
A few days ago I prepared some Walnut blanks for the Frame Cross Piece which joins to the Frame Upright shown in Fig-33 - and promptly forgot about them - so today I looked at both how to hold them and skim the surface. The process in CorelDRAW! might be interesting so I’ll try to explain my thinking. Fig-44 shows the component outline within the blank limits. The problem I have to address are how to clamp the blank to the table so that the surface can be ‘skimmed’ without the cutter colliding with clamps. I could, of course, drill & counterbore holes but that would be more wasteful of timber which could be used for other components.
To skim the surface I use a ‘Fly Cutter’ (Fig-12 on WIP-3) which cuts a swathe 50mm Ø so can cover the widest part in one pass. To do so I need to use an [Engrave] MOP which is a single curve.






The red circles on Fig-45 are the plot of where the cutter will sweep and the Grey blocks show where the clamps need to be positioned to avoid the cutter path but they could be turned to give a little more clearance. The Blue crosses show the position of the clamping threads in the table.






This part needs to be machined from both sides so although the centre joint is shown ‘dashed’ to indicate it is on the opposite side, I’ll machine that first - along with the two circular recesses - and use that joint to re-position the blank to cut the end joints. That will be done by screwing a block (green - purple outline) to the table and cutting that to suit the joint, thus fixing the blank in both the X and Y axes.

It might even be best to leave the outline as a Second Op. so that I can skim the second face using the same clamping technique. .... hmmmm..... writing this W.I.P. does have the benefit that some things come to mind sooner through trying to communicate my thoughts. It may well be that I’d come to the same conclusion but only after starting work on a component and then having to change the methodology.

3rd Oct
I didn’t bother with the second ‘skim’ since the first brought the blank thickness within 0.2mm of the target so this morning I got on with making the location jig for the Second Op.. (Fig-46) The first attempt showed that I’d missed a setting in the parameters for the width of the location peg — I’d left it to cut [Outside] (the default) whereas it should have been set to cut [Inside] — there are so many settings so it is easy to miss one if you lose concentration for a moment or two. A ten second job to correct the G-Code but another half hour to cut another blank, drill the fixing holes and mount it on the table before starting to machine it again.





As expected, once I’d corrected the G-Code, the Location Jig was a perfect fit for the previously cut joint so it was a very simple matter to clamp the part machined [Frame B] component ready for the second side joints and holes to be machined and finally the outline cut out.

Fig-47 shows Frame [A] and fitted together.
*


*

========================================================================

Well, that went pretty much to plan though I might need to adjust the size of the images.

I'd be grateful for feedback regarding this method of posting -- ie. if it is preferable to the .PDF/.PNG image attachments.


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## Yojevol (3 Oct 2020)

I found recently that adjusting photo size is easy. Click or tap on the inserted pic and its boundaries will show. Just drag a corner node in to reduce your pic size. 
Brian


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## J-G (3 Oct 2020)

Thanks for that Brian - much better than re-sizing in Photoshop, Deleting the original and Attaching the new version.

It only reduces the display size of course, the file size will remain the same (I imagine).


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## Yojevol (3 Oct 2020)

@J-G I've just been looking through your posts on the CNC discussion thread. You mention that your bearing design is still under consideration. Having been through the mill on this subject in recent months, I thought I'd put up a few thoughts.
My first clock attempt was Clayton Bower's Simplicity which, like many designs, relies on a simple hole in the gearwheel running on a brass shaft. In order to keep the wheel running true, ie, minimal wobble, a good length of bearing is required. This is often achieved by adding a boss to the basic gear. 
For my second effort I have designed it to be as narrow (front to back) as possible which means no added bosses. I thought little deep groove ball bearings would be the way to go; mounted directly into my 6mm ply gears. However it turns out that these bearings have a considerable amount of angular play, so they are not the answer to wobbles. My next try was with needle bearings but on these small sizes they're not much better than ball bearings.
The solution I have ended up with is using 2 bearings ganged together which increases the overall thickness from 6 to 8mm - I need a mm or 2 each side for clearance anyway. Where a gear has to be fixed to its shaft it is often possible to fit 2 well spaced bearings and that's fine as long as I can fix the shaft at a true right angle (that can be a challenge).
I would certainly recommend doing a few experiments before committing yourself to cutting your nice timbers in anger. You may well be in a better situation using quality wood rather than ply. Also your CNC router may give better quality holes compared with my ply drilling methods.
My next project is probably going to be a repeat of my No.2 with a trial use of lignum vitae (just bought an old bowl) as bearing material.
I'm just thinking of doing a thread on the present project - taking it through the final assembly stage. Here's a little spoiler
Brian


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## J-G (3 Oct 2020)

Thanks for that feedback Brian. I'm sorry to have given you the impression that bearings are are still under consideration, those details were sorted well before I started selecting timber to machine.

All of my gears will be fixed to shafts via a grub-screw clamping on to a milled flat. The bearings will be at the ends of each shaft - though in three cases the shaft will go through at one end. Most bearings (all ordered and delivered) are Deep Groove but two are Needle Roller. I've used both in the past without having any issue with 'wobble'.

Here's a drawing of the 1st Train Spindle which also carries the Hands - I've added the bearings (Purple/Silver) to show where they sit. [Edit] - now added the location of the gears which are assembled with a spacer which is glued in (red line = glue line).





Certainly solid hardwood and CNC gives me an advantage over Plywood and a Pillar drill but knowing the limits of your tools is part of any engineering equation 

Good luck with the 'Bowling Ball' - I was given two a while back but every attempt to get anything useful out of them has been thwarted by bits falling off due to shakes. My Grandson did make use of a small block to hold some Silver tubes that he needed to file to length but even that broke apart - fortunately it gave him the chance to push the tubes out when finished!

I did look at your 'spoiler' but [DropBox] has a mind of its own so I could only run it once.


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## MikeK (3 Oct 2020)

J-G said:


> Well, that went pretty much to plan though I might need to adjust the size of the images.
> 
> I'd be grateful for feedback regarding this method of posting -- ie. if it is preferable to the .PDF/.PNG image attachments.



Don't bother resizing images, unless they are larger than 10MB. You can upload PNG and JPG images in their full-size format in line with your text. The XenForo software will automatically resize the image for viewing based on the device. Clicking on the embedded image will display it in its full size.

It's not possible to embed PDF files, but they can be attached to the post as you have been doing.


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## J-G (3 Oct 2020)

Thanks Mike. It was just that when the images came in they seemed larger than I'd created --- I hadn't considered what you have intimated in-as-much-as the forum can be viewed on devices other than a PC. 

There was/is an option to embed a Thumbnail or Full Image - I've selected Full but Thumbnail might be more efficient, if click on the thumbnail displays the full version.


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## MikeK (3 Oct 2020)

J-G said:


> Thanks Mike. It was just that when the images came in they seemed larger than I'd created --- I hadn't considered what you have intimated in-as-much-as the forum can be viewed on devices other than a PC.
> 
> There was/is an option to embed a Thumbnail or Full Image - I've selected Full but Thumbnail might be more efficient, if click on the thumbnail displays the full version.


Please select Full. This will display the image in the post without any action required by the viewer. If you select Thumbnail, then the viewer must click on the image to display it in full size.


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## donwatson (4 Oct 2020)

Thanks again JG. This is fascinating stuff for me and now that Yojevol has joined the discussion it helps me to rethink my position regarding making wooden geared clocks. I was beginning to think it was not for me but I now feel I should give it another go. (Whenever time permits).
I find the PDF is a good way to store the articles on my computer, a click and it downloads into my 'Clocks' folder. But I also like the way you have just presented it on the forum, it is clear and I can understand what is going on at a glance. I like reading it here but I like a copy on my computer that I can peruse at my leisure without having to log on to any forums, though I have to admit I wouldn't be here without the forum. Hope this helps.
EDIT Hi JG, I have been looking through this fascinating article and can only say it has re-kindled my interest in making a wooden geared clock. I have found a piece at the end of WIP 7B where you designed the composite gear and made it from 5 pieces. It puzzled me for a bit as I would have thought 4 or even better 6 pieces would have been easier to work with (almost mental arithmetic) but then thought it would be in keeping with the statement you made at the outset about using the 'Releaux Polygon' so that sort of solved that.
At the end of this same article, in the downloaded PDF, the last line is missing ??
Thanks again for this fascinating insight.
take care
Don W


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## J-G (4 Oct 2020)

Thanks Don - very useful feedback - I'll certainly continue with the .PDFs


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## J-G (5 Oct 2020)

Hi Don - just noticed your EDIT re WIP-7B so a new version is attached. It's apparently too late to do an edit of my original post.

Yes - 4 or 6 segment would be easier --- IF you are doing the work purely by 'Hand' or even a manual milling machine or scroll-saw, Using CNC frees up all the constraints of accurately moving a work-piece 72° - rather than 90° or 60°. Even a 7 side (51.42857...°) becomes feasible  and of course for clock making 7 can be important (days of week). Mind you, I've seldom shied away from those sort of difficulties - back in 2007 well before I thought about CNC, I built a skeleton clock in Brass with a seven spoke 'Day Wheel'.

It's not so much about the 'Reuleaux' polygon (curved side and constant diameter) but a [Pentagon] to match the dial.


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## J-G (5 Oct 2020)

4th Oct
I can’t explain why it has taken me so long to appreciate that using the surface of the work as [Z = 0] is by far the easiest option. Up to now I’ve been using a stepped block with 10, 11, 12 ----> to 20mm to set the cutter position and that has meant that when setting the parameters in CamBam I’ve had to work out the target depth allowing for the clearance above the surface - see Fig-35 in WIP-7B.

A chance remark by an experienced CamBam user (on another Forum) and the issues I was having with the depth of the centre joint on the [Frame B] component made me re-think the whole methodology. This meant that I had to re-visit CanBam to modify the [Surface] and [Target Depth] parameters for all the MOPs but that’s a small price to pay for the greater convenience afforded.

I was having some problems with skimming the surface because the blanks came directly off the bandsaw - well I did run one face on the Linisher but to all intents and purposes the top surface was ‘sawn’ so therefore had undulations so wasn’t ‘flat’ nor particularly parallel to the bottom surface - well, within less than a millimetre but not close enough to provide an accurate datum. I created a [Skim Surface] MOP taking two cuts of 0.2mm so if the surface didn’t clean up I could adjust Z0 by 0.2 to 0.4 and run it again. Once the surface is ‘clean’ the next tool can be [Zeroed] to that and whatever the depth of cut needs to be will be accurate to that surface simply by using ‘Stock Surface’ = 0 and ‘Target Depth’ = whatever figure is needed - - - - Result!

Whilst I was waiting for the Denford to complete its work cutting out the [Frame B] component I got on with work on the Lathe and since the Pendulum Rods had arrived I decided to start on the components for the Bob adjustment. This consists of a small brass section which will be epoxied into the end of the Carbon Fibre tube - I did think about putting an M4 thread directly into the tube but the suppliers warned against trying to cut threads as they thought that the fibre would just crumble. Only time will tell whether I need to also use a cross-drilled hole and pin to secure this section to the Carbon Fibre tube. This small section just has an M4 thread which will have a 130mm long brass rod with 50mm of M6 thread screwed into it.

When assembled, this ‘rod’ will pass through the Pendulum Bob and into the [Adjusting Nut] in the centre.

Regrettably, my phone camera won’t show the component adequately so I’ve resorted to showing the assembly as a drawing (Fig-48). I've rotated it 90° to reduce the white space on the forum.







Looking at which part to make next I decided to carry on with the Pendulum - in fact the [Bob] which although I originally designed as a conventional disc, I’ve now decided to make as a Reuleaux Pentagon. I still haven’t decided whether it should have the point Up or Down! 

I have a ‘lump’ of Walnut which was given to me some while ago with the caveat that it came from a sack of ‘firewood’. There is enough to make three - you will have noticed, I’m sure, that I’m making 4 of everything with the hope that I might end up with at least two clocks. This is essentially a ‘learning CNC’ exercise so there are bound to be mistakes made but hopefully by the time I’ve made 4, I should have sorted any issues. This ‘lump’ was accompanied by another three, two of which really are firewood but I can get the fourth Bob out of the last ‘lump’. Fig-49 shows the 'Lump' with a template attached to determine the location of the centre hole.






Today I've cut the outline roughly to size and drilled/reamed a 6mm hole in the centre as a datum. This will become the clamping hole, positioning the blank at X0/Y0, but the first thing that needs to be done is to get the thickness down to close to finished size. Ultimately the surface will be curved and therefore machined on the lathe but I also need to drill a ¼” hole from top to bottom (125mm) and for that I need the blank to be flat and parallel so that I can hold it in an independent four jaw chuck on the lathe so that there is a fighting chance that the hole will be central and straight – It is much better to turn the work rather than the drill and I will start with a stub drill moving on to a ‘Jobbers’ series and finally a long series . If necessary I also have a 12" long drill if the long series doesn’t quite cut the mustard. This will be an ‘interesting’ operation!!


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## J-G (8 Oct 2020)

6th Oct
Machining the Pendulum Bobs has indeed been interesting - and I haven’t even looked at drilling the through hole! I originally intended to use a 6mm cutter for the outline but then realized that the only 6mm cutter I have is only capable of cutting up to 15mm deep and I need at least 25mm. Fortunately I do already have a 63mm long router bit but it is ½” Ø so I had to re-jig the G-Code accordingly.

The first P-Bob blank I left as it came off the saw which meant that the ½” cutter was taking a full width cut for about 50% of its travel but by the time that it was 24mm deep there were issues with parts outside the pentagon breaking free and causing some surface damage. Not that it mattered too much since it was a ‘roughing’ cut and the finishing cut of 0.3mm would clean that up but it made me decide to trim the other three blanks to within 5mm of the finished size before mounting them. Once I’d done that it was just a matter of letting the Denford take its time and a travel distance in excess of 20m @ 200mm/min does take some time.

While that was being done I did the lathe work on the Pendulum adjusting nuts so the next job will be cutting the ridges in the sides of those. I haven’t cut Brass on the CNC machine before so I first made a ‘dummy’ out of Maple just to check that the G-Code did what I expected. You’ll notice in Fig-50 that I’ve crossed out the original design dimension of 30mm and penciled in 28mm. The brass I had on the shelf was only 1-1/8" diameter so I took the pragmatic approach and re-designed the part rather than order new.




*Fig-50*

The brass billet is there because I did a physical test to make sure the Denford could handle the forces needed to cut brass but I forgot to turn it around so that you could see the test cut. In fact it proved that I needed to reduce my estimated feed and speed. Rather than cut a ‘Profile’ I had decided to use a ‘Drill’ Canned Cycle MOP so that I could easily control the amount of material being removed with each pass which I’d assessed to be 0.4mm. It would also give me a cleaner edge to the indentations though to some extent these will be smoothed out when I do the final polishing - Brass deserves to be polished! - Fig-51 is a drawing of the four cuts that I need to take and Fig-52 shows the Denford part way through one of the cycles.








*Fig-51 . . . . . . . . . . . . . . . . . . . . . . . . .Fig-52*

7th Oct
To give you a clearer idea about how these parts go together Fig-53 shows the Pendulum Rod (Carbon Fiber Tube) with the connecting piece as well as the Adjusting Screw and Nut.



*Fig-53*

Eventually they will all be inside the Pendulum Bob of course but since I haven’t yet drilled that hole, this just shows you where they will fit - assuming I can drill a straight hole through the Bob.

I said that drilling the hole would be ‘interesting’ well it certainly was! The first thing that brought me concern was the fact that the Bob Blanks do not have a ‘flat’ side which I can use as a datum so positioning them in a four-jaw independent chuck needs to be done with some care. The ‘points’ can be used to check that it is held centrally the one at the top must lie on the lathe centre-line and the next two must be equidistant from the centre-line.

To check this I used pointers in the lathe tool-posts and the first one took me about 10 minutes to get to a satisfactory position. In Fig-54 you can see the two pointers, one connecting to the top point and the other locating the side point. To check that the Bob was centred, I could flip it over 180° and the pointers should still connect to both points.




*Fig-54*

It is also necessary to make sure that the Bob is centred when rotated 90°. To do this, all I needed to do was set it upright and bring a centre drill up in the tail-stock. The centring is not hypercritical so holding a steel rule with the centre-drill and making sure the two sides are equal. Fig-55 shows this. I could have done this by checking the cross-slide dial reading for each side as well.




*Fig-55*

Once I was happy that the Bob Blank was centred I could start the lathe and drill a centre hole followed by the various length drills, finishing with the 12" long ¼”. This was necessary because although the long series drill did break through, it is only 6mm diameter and the hole needs to be a clearance for the 6mm Ø adjusting screw. Although the blank is not a solid round, the fact that it is centred means that there is no danger of it being ‘out of balance’ but even so there is no need for high speed. In Fig-56 you can see the long series drill but the blank is a blur.




*Fig-56*

Now I have to make a small jig to locate the Pendulum Bobs so that I can position them so that I can cut the centre slot accurately in line with the side that is already done - but that’s for another day!


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## donwatson (8 Oct 2020)

Thanks again JG


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## J-G (8 Oct 2020)

I've now edited my last post to add an image that I referred to but didn't insert and add annotations for the Fig. Numbers.

The new image is Fig-53 which shows the Pendulum Bob with the Adjusting Screw/Nut and the bottom of the Carbon Fiber Tube which is the Pendulum Rod. I would appreciate opinions as to the orientation of the Bob - whether the point should be UP or DOWN?


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## Yojevol (8 Oct 2020)

1 for UP


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## J-G (9 Oct 2020)

Can anyone suggest why this thread - and the one by jonzjob - has lost the reads & replies information?

This also inhibits the thread rising up the order when a new reply is posted.


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## MikeK (9 Oct 2020)

J-G said:


> Can anyone suggest why this thread - and the one by jonzjob - has lost the reads & replies information?
> 
> This also inhibits the thread rising up the order when a new reply is posted.



I moved both threads from the General Woodworking forum to the Projects forum. If you, and everyone who is watching this thread, have Notifications enabled, you would have received a notice stating why the threads were moved. The notification icon is the little bell in the upper right corner of the screen to the right of your user name.

The threads you see, with no reads or view counts, are temporary redirects to the threads in the Project forum. The redirect will expire soon, and you will not see it in the General Woodworking forum. Until the redirect expires, every time you click on the thread in the General Woodworking forum, you are automatically taken to the thread in the Projects forum.


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## Yojevol (9 Oct 2020)

MikeK said:


> I moved both threads from the General Woodworking forum to the Projects forum. If you, and everyone who is watching this thread, have Notifications enabled, you would have received a notice stating why the threads were moved. The notification icon is the little bell in the upper right corner of the screen to the right of your user name.
> 
> The threads you see, with no reads or view counts, are temporary redirects to the threads in the Project forum. The redirect will expire soon, and you will not see it in the General Woodworking forum. Until the redirect expires, every time you click on the thread in the General Woodworking forum, you are automatically taken to the thread in the Projects forum.


Thanks for your explanation MikeK and also for your notification to me about my comment on Jonzjob's clock. However i think my comment is still relevant and it should have been migrated along with Jonzjob's thread. I will be grateful if you will reinstate it in its 'correct' location. 
Brian


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## donwatson (9 Oct 2020)

1 for point down


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## J-G (9 Oct 2020)

MikeK said:


> I moved both threads from the General Woodworking forum to the Projects forum. If you, and everyone who is watching this thread, have Notifications enabled, you would have received a notice stating why the threads were moved. The notification icon is the little bell in the upper right corner of the screen to the right of your user name.
> 
> The threads you see, with no reads or view counts, are temporary redirects to the threads in the Project forum. The redirect will expire soon, and you will not see it in the General Woodworking forum. Until the redirect expires, every time you click on the thread in the General Woodworking forum, you are automatically taken to the thread in the Projects forum.


Thanks for the explanation Mike --- I did notice the [Redirect] and did click on it but it had no effect. I hadn't noticed the alert on the [Bell] though. I didn't know there was a [Projects] forum and had some difficulty finding it and I still haven't found jonzjob's post but I'll look again after posting this.


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## J-G (9 Oct 2020)

Yojevol said:


> 1 for UP





donwatson said:


> 1 for point down


That's interesting - and aligns with my thoughts - since I'm making four of these I've done two of each 

I'm sure there will be a difference explained by 'Physics' but lack the knowledge to quantify what it might be so the only criterion I have is aesthetic - ie. how does it 'look' - and I still can't decide which I prefer.


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## Yojevol (9 Oct 2020)

J-G said:


> That's interesting - and aligns with my thoughts - since I'm making four of these I've done two of each
> 
> I'm sure there will be a difference explained by 'Physics' but lack the knowledge to quantify what it might be so the only criterion I have is aesthetic - ie. how does it 'look' - and I still can't decide which I prefer.


That's a pity. I thought you be democratic and go sideways. However you have found another way to sit on the fence


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## okeydokey (9 Oct 2020)

Hi another vote for down looks aesthetically better


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## AES (9 Oct 2020)

Again, thanks to MikeK for moving this thread (and no, I didn't see any "notification" but it IS possible I missed it).

And as already said, thanks to J-G for an excellent WIP & pics (I DO understand your initial use of .pdf format and have done the same myself for a couple of long posts, but I must say since the "takeover" of UKW, the new software makes the job of a "sensibly" formatted document with pix in the "right" places is MUCH easier than it was before).

LOVELY clock Sir.


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## J-G (9 Oct 2020)

AES said:


> ...but I must say since the "takeover" of UKW, the new software makes the job of a "sensibly" formatted document with pix in the "right" places is MUCH easier than it was before.



I'll agree there AES - it still needs some lateral thinking on occasion though, - for instance 'white space' is ignored so where I wanted to put the Figure Number under Fig-52 it defeated me until I put some dots between the two anotations and made them white. Even then (I've just checked) if the display isn't wide enough then it moves the image down! I (we?) have to accept that this is a text forum not a Graphic Layout program 



AES said:


> LOVELY clock Sir.


Thanks


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## AES (9 Oct 2020)

J-G said:


> I'll agree there AES - it still needs some lateral thinking on occasion though, - for instance 'white space' is ignored so where I wanted to put the Figure Number under Fig-52 it defeated me until I put some dots between the two anotations and made them white. Even then (I've just checked) if the display isn't wide enough then it moves the image down! I (we?) have to accept that this is a text forum not a Graphic Layout program



Yup - we were obviously "brought up in the same school" when it comes to creating "readable reports" (!), and I must say, that using the relatively restricted laptop screen makes the job a bit more difficult too - BUT this new software is certainly streets ahead of the old UKW software. What I haven't tied yet is writing a whole "report" in MS Word, placing the pix (and their titles) exactly where I want them (that's also a bit of a fiddle with Word but I learnt those tricks years ago) then doing a simple cut & paste direct into the Forum. I shall find out soon though, as a long WIP that I started off in .pdf over a year ago now, now needs to be updated and extended, and I shall, try just that. i.e. no more .pdf. So "We'll see", but yeah, clearly a text-based system, that "just manages - more or less" to handle graphics too).

Cheers


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## J-G (9 Oct 2020)

AES said:


> ...What I haven't tied yet is writing a whole "report" in MS Word, placing the pix (and their titles) exactly where I want them (that's also a bit of a fiddle with Word but I learnt those tricks years ago) then doing a simple cut & paste direct into the Forum.


Good luck with that!!

MSWord not only has its own idea of what you might want it also changes any imported graphic to its own format which may or may not be acceptable to the forum software.


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## AES (9 Oct 2020)

Yeah, I know J-G, but at least I can - usually! - make it do what I want (BTW, I deliberately STUCK with Word '97 - THAT works for me!).

But as said, "we'll see".


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## J-G (12 Oct 2020)

There's nothing wrong with older versions of software AES - unless it's Microsoft's of course  I do have a copy of Office 2002 from which I use Excel but for writing (not that I do much of that) I use WordPerfect - in my opinion a vastly superior word-processor.

Anyway, enough of that discussion, I have another two pages of the W.I.P. - PDF 12 attached.
========================================================================

*9th Oct*
The second side of the Pendulum Bob Adjuster Nut slot has now been machined along with the recess for a brass plate which is there to prevent wear caused by the brass nut rubbing against the Bob. On reflection, I suspect that this is overkill since the only time that any adjustment will be made, after initial set up, is when (if) the clock is moved to a different location - either Latitude or Altitude - and the Centre of Mass of the Pendulum needs to be changed due to the change in the value of gravity. The brass plates have also been cut to size and drilled for the Adjusting Screw to pass through. Ultimately they will be epoxied in place. Fig-57 is the [Bob Assembly] with the adjusting Screw and Nut in place. The Pendulum Rod is not yet attached as I still want some freedom.



*Fig-57*​I now need to make a fixture to position the Bob ready to have the face ‘Domed’. This will need to be a billet of Ash or Beech fixed to a Lathe face-plate, turned with a suitable size ‘boss’ in the centre and then that held in the Denford so that the precise size of a plug to fit the Adjusting Slot can be machined. Both sides of the Bob can be done using the same fixture as it will be supported by the tail-stock and a live centre. Before I do this, I can get on with making the [Frame Brace] as I’ve selected the material from a very nice piece of white Ash that is left over from a Presentation Case project. The blanks have been sized, had clamping holes drilled and the first one has been ‘CNCed’ - Fig-58 shows it on the Denford table alongside the piece of card I use under each component to try to minimize damage to the ‘Sacrificial’ table – It took me some time to make that with the 67 threaded inserts so I would sooner cut into the card than the table!




*Fig-58* 


*Fig-59 


Fig-60*

After I’d removed the waste part from the Brace, I realized that I could have also machined the other face to size by surface skimming on the Denford as I had done the first face. To do that would need the other side to be counter-bored to accommodate the clamping screw heads, just as the first side had been. It would also allow me to cut the other side of the tenon which fits into the [Frame A] part as well so the other three blanks were re-mounted on the milling machine to do just that. The result can be seen in Fig-59/60. In Fig-60 the face has had a clean up on the Linisher so that face will be down on the table for the first cuts which will enable me to clean up the face in Fig-59. After the shape has been cut out (kept in place by the ‘Holding Tabs’) the blank can be turned over - using different clamping holes - so that I can skim the ‘cleaned’ surface to size and cut the other side of the joint. I’ll finish the first Brace to size on the linisher and mill the joint. Nothing about this component is really ‘critical’ and the only reason I’m doing it on the Denford is due to the shape.

I’ve also worked out what Walnut I need for the rest of the Frame and Dial so I’m going to a couple of local(ish) wood-yards later this week to select a 2.1m board of 6" x 1½” which I’ll have to ‘slice and dice’ into 50 pieces.

From Fig-61, you’ll see that there will be some spare. I’ve had quotes from both but I want to see exactly what each are really offering. One is at £55 and the other is £80 for Grade A or £65 for Grade B. The fact that I paid nearly £70 for a 600mm long 4"Sq. piece about 6 months ago makes me think that the Grade A will be my best bet.





*11th Oct*
Waiting for the Denford to complete the work on the Frame Brace, I started looking at my options for Holding/Driving the Pendulum Bob to finish the face. I have a small (4"Ø) faceplate which will be plenty big enough but holding it on the Denford table with a sacrificial plate attached would be challenging since it is 28mm thick. I can get clamps on the bare plate so I could make space for the clamps by using a triangular block. A piece of scrap floor-board is perfectly good as the drive peg. First though I had to make a locating peg so that the face-plate could be clamped accurately and an oddment of Ash fitted that bill perfectly. It was a five minute job to first draw the position of the locating peg (on the CNC Table) and in accurate register with the oblong driving peg for the Bob and then create G-Code to do the work.




*Fig-62*​That would both position and drive the Bob but it would also need to be supported by the tail-stock since even a good tight fit would be insufficient to stop it wanting to creep off. Fig-62 has both drive and Tail-stock support on the lathe bed and Fig-63 is the Bob mounted on the spindle, supported by the tail-stock and with a tool-rest which I used to hand turn the face to the domed shape you can see in Fig-64.




*Fig-63 


Fig-64*

It will have to be sanded to a fine finish and for that the tail-stock support will need to be removed but as I will be applying pressure towards the head-stock, that will stop any possibility of it wanting to come off the peg.
​As predicted, I didn’t have a problem sanding the faces so, because I skimmed the face by hand, I started with 80 grit then went through from 180g to 400g before using Sanding Sealer which was cut back with 600g and finished with MC Wax. I’ve only taken one of the four as far as the wax and even that is only one side so the driving fixture will be retained - it will always go back to the same place on the lathe spindle so I don’t have an issue about de-mounting.





*Fig-65*​
Fig-65 is the first Bob with one face ‘finished’ mounted on its Adjusting Screw and Nut. I say ‘finished’ but in reality I’ll need to give it another coat of MC Wax and eventually it will be buffed just as the rest of the Walnut Frame and Dial will be.

Now I can return to the second stage of the Frame Brace which I put aside to make the drive fixture for the Bob so I'll report on the problems that I encounter doing that in the next installment.


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## donwatson (12 Oct 2020)

Thanks again JG. You are moving along very well with this project and I really enjoy what you are doing/explaining. Thanks again.
Don W


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## J-G (12 Oct 2020)

Thanks for that feedback Don. I sometimes wonder if I'm giving too much detail by treating the WIP too much like a diary but your comments seem to say that the detail IS useful. My feeling is that it might provide some ideas for other projects.

Your pic_3 does show a discrepancy between the size of the shaft and the hole and I agree that you're on a hiding to nothing with that set-up. Wood will move on a daily - even hourly - basis and the chance of the timber in the frame matching the movement in the spindle is remote at best so you have to allow a degree of 'slop' which is definitely what you don't need for the Escape wheel.

If you don't have the means to make steel spindles then the minimum I would consider would be Deep Groove Ball Bearings which you might be able to retro-fit to the frame.


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## AES (12 Oct 2020)

Well J-G, I can only speak for myself of course, but when you say:

"Thanks for that feedback Don. I sometimes wonder if I'm giving too much detail by treating the WIP too much like a diary ..... " I would say "Not at all Sir. Go for it, the more detail the merrier!"

As said, that's me, and is also my own "style", which I've found some members seem to like, others not. As ever in life.

But I will say that I do appreciate just how much time and effort it takes to get such posts ready, and at least from me "Thanks, please continue".


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## J-G (12 Oct 2020)

Thanks AES - that is useful feedback as well - and though it does take time, I don't consider that wasted, sometimes I'm ahead of myself and just jotting down what I 'intend' to do will help to determine what I actually do.

A bit like learning anything (in my case often music/lyrics) by physically writing the lyric down it has to go through a number of senses and being a Tenor who doesn't read the Bass Clef well, the mere fact of resetting it to the Treble Clef aids the learning.


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## AES (12 Oct 2020)

Funnily enough J-G, I (try to) sing Bass-Baritone in the choir I belong to. I'm not clever enough to do all that music transposing stuff, but I DO write out the lyrics - often several times.

Also in our choir we often sing foreign language songs, and especially for French lyrics, (at which I'm absolutely useless), I make my own "phonetic English" version of the French lyrics. You should see the look on my (Swiss) choir colleagues' faces when they ask to look at my own (English phonetic) "special cheat sheets"!  

Thread drift (of course) but so far all my WIPs have been done during/after the actual work. "Pre-writing" at least some ideas may well make some sense for me, thanks.


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## J-G (13 Oct 2020)

Thread drift is de rigueur! I'm in three choirs - though not rehearsing at the moment due to Covid restrictions - and have a go at Italian, Latin, German, Russian, Welsh - even Dutch !! - but don't give me French  - there are a few pieces (Cantique de Jean Racine...) but in general  

One choir has a concert planned for July next year in Dresden as a repeat of one where Dresden's Neuer Chor joined us in Coventry Cathedral in 2019.

Glad you find the concept of "Pre-writing" of interest, Today  Yesterday I started re-looking at how I'm going to make the gear blanks and the write-up for that is pretty much all 'before the fact'.


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## donwatson (14 Oct 2020)

Great comments chaps, I think a bit of forward thinking does no harm, and indeed will aid the the process to run a bit more smoothly at the end up.


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## J-G (14 Oct 2020)

I spent all day yesterday -- and a lot of Monday -- working out the segment detail for the Escape Wheel. During the Clock 'General Design' process I was only concerned with the overall size and shape of the Gears so didn't go into the nitty-gritty detail of how the blanks would be created. I knew that they would be segmented since I wasn't using plywood and at only 5mm thick solid hardwood will not remain flat enough at 120mm wide. 
I alluded to this in WIP-7 but hadn't taken on board how it would be achieved. WIP-13.PDF attached. 
=======================================================================
*12th Oct*
I’ve been putting off the preparation of the Gear Blanks for too long. Waiting for inspiration to some extent and trying to persuade myself that trying to minimize waste could be a false economy (and I can’t get to select the Walnut until Friday). I’ve already cut two pieces of Maple out of a 15mm thick billet that are really a bit too close to 5mm thick (the finished size) and all I have left is a 2-3mm sliver. The next strip I cut will be down the middle so there will be some ‘meat’ to provide an easy finish trim.

The Maple I have is 48mm wide and was bought with the intention of making up a 5 segment ‘ring’ plus a centre ‘boss’ - see Fig-37 in WIP-7 - but I now see that 48mm is insufficient to cover the 72° necessary to have the grain running in the correct direction ( it would need to be 83mm wide) so today I did some more work in CorelDRAW! & SketchUp looking at a 10 segment option. This is for the Escape Wheel which is 120mm Ø - ie. the ‘worst case’ situation - the smaller gears won’t be a problem. I also have Maple at 64mm wide but only 10mm thick which is OK for the 72 T gear which is 8mm thick (but will still need 6 or 8 segments).

Fig-66 is a screen-grab of the SketchUp image in which I’m testing how a 10 segment option would work and Fig-67 is the next iteration done in CorelDRAW! From that I can move the segments about to eventually create the .DXF file which will be used in CamBam to create the G-Code. 




. . . . . . . .



. . . . . . . . . . . . *Fig-66*

*13th Oct*
I’ve looked again at this problem, so Fig-68 is the latest (hopefully the final) iteration, Naturally there will be only one centre but there will be 5 each of the other two. Making segmented components is usually just a matter of making 6/8/10/12 etc. pieces with the appropriate angle (60°/45°... etc.) and simply gluing them together with butt joints but for gears I need more strength so have designed half-lap joints. It makes the whole thing more complex but vastly superior. 

Using Plywood would overcome all the issues of course but has the disadvantage of ‘Appearance’.




The shape of the two different segments can be seen in both plan and elevation in fig-69. They will both be made using CNC and all 5 of each together from two blanks - see Fig-70




. . . . . . 




It’s somewhat disturbing to realize that another day has come & gone and nothing material has come out of the workshop. A great deal has been done on the PC of course and all the G-Code has been produced so tomorrow I hope that I might have at least an Escape Wheel blank glued up ready for the outline teeth and spokes to be cut.


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## Yojevol (14 Oct 2020)

Just spent a few minutes trying to get my head round this. So, if I'm right, you're going to end up with a 10mm thick escape wheel fabricated from 10mm thick pieces joined by halving joints. The only comment I can make is that the outer rim will be made up with a mixture of solid and 2-ply wood. The strength, not that it needs much, will be limited by the single ply sections. At 10mm thick there is plenty of surface area for a simple butt joint which would be stronger than the timber itself, especially with the accurate shaping that your router can provide.
I'm really interested in this section of the work because I'm just beginning to think about making my next clock with solid wood gears. I will have 2 options. (a) similar to your method but with simple segments going right into the centre, or (b) making my own ply from a large amount of veneer which I really ought to find a use for. I'll probably experiment with both.
Brian


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## J-G (14 Oct 2020)

Not quite right Brian - the Gear will be only 5mm finished - well that is the current plan - after I've made the first I might change that to 6 or 8 but I don't want to go any thicker if I can help it. The 48mm wide Maple at 15mm thick does give me the option of going to 6.5 ish - if the band-saw doesn't wander  
This is as much to do with economy as anything - I'd hate to mill away more than half of the board!

I don't believe that the strength will be reduced by the half thickness for the same reason as you cite the glue strength of the butt joint - - - - but I could be wrong 

Whatever - it's a great leaning curve both as far as making Gears and the whole concept of CNC machining (which is what this whole exercise is really about).


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## donwatson (15 Oct 2020)

Thanks again JG. I am afraid you are both beginning to lose me in these details. I need some time to study the PDF.


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## J-G (18 Oct 2020)

I hope you've had enough time to assimilate those details Don  It took me some time to get it clear in my head but once it 'clicked' it became obvious. As you'll see from the next installment (.PDF attached) I've made the first Escape Wheel - based on the half-lapped segments, I've also made some spindles and Pinions.....​===========================================================================
*14th Oct*
The larger segment went to plan with no problems but the smaller one gave me a few anxious moments as I watched the 3mm cutter get closer to the clamping screws than I have bargained for! It just cleared the first but partially unscrewed the second. I was ready with the Emergency Stop though and once I’d turned down the head, removing the damage, I could re-secure the blank and continue the G-Code from where it had stopped. 

This was caused by my ‘thrift’  since I’d decided to ‘save’ the 50mm of Maple that was left over after cutting the two lengths needed and I’d also put just two clamping holes on the centre-line rather than 6 holes on the edge as I’d had to do with the large blank. You’ll see the difference in Fig-71 & 72.




*Fig-71*




*Fig-72*


After separation and a little clean up, I found it a little challenging to get all segments to sit nicely together until I hit upon the idea to screw the centre down. Once I’d done that, the glue-up was straight forward. I was anticipating having to screw 10 blocks in a circle and add wedges to press them all to the centre but eventually was happy with just a panel pin against the end of the long segment. (Fig-73) Whether it will ‘move’ overnight is another matter!



*


Fig-73 . . . . . .. . .Fig-74

15th Oct*
There is a slight ‘bowing’ due no doubt to the fact that I didn’t take enough care after hammering the pins in to also clamp the whole assembly ‘flat’. Nothing that a short time on the Linisher couldn’t overcome but I’ll know for the next one.
Spent the morning re-doing the G-Code for the spokes, Teeth and Pins. The later was of some concern since I want them to be a press fit - though they will be glued as well - and although CNC machining is accurate, the actual diameter of a drilled hole is governed by not only the diameter of the drill used but also by how accurately it is held in the collet. Because I made my own holder for 1/8" shank cutters (Fig-74) I was anticipating some minor ‘wobble’ and when I’m looking at 2mm Ø, a 1.9mm might well cut just a smidge oversize and when I measured the St-Steel pin material at 1.97mm it seemed sensible to do some test holes.

I was pleasantly surprised to find that the very first test hole with a 1.9mm dill proved to be accurate and a good ‘press fit’.

Because the drill was in place, it made sense to keep it there and change the order of operations, so, as you can see in Fig-74, the 30 holes for the Escape Wheel Pins were drilled before the Spokes or Teeth were machined.

The CNC operation went pretty much to plan though there were times when I thought that my 3mm cutter was cutting oversize - it turned out that I had left the offset between roughing and finishing the same so the second cut although being with a smaller cutter only trimmed a little out of the places there the larger cutter couldn’t reach. The re-writing of the G-Code soon sorted that so I now have one of the four Escape Wheels (Fig-75) ready to have the pins inserted. It still needs to have a recess machined to take the spacer between it and the Pinion which will also carry the grub-screw which locks it to the spindle. The centre hole needs to be enlarged as well but these two ops. were always going to be done on the lathe.



I’m quite happy with the thickness at 5mm but because I have the 15mm thick Maple I’m minded to simply cut that down the middle and adjust the depth of the joints once I’ve cleaned up the surface so the other three may well finish up at 6mm or just over. That will just mean that the spacers need to be a bit shorter. The current design is 16mm so there’s enough ‘meat’ in there for the 3mm grub-screw even if it goes down to 14mm.
*
16th Oct*
I have to visit a wood-yard (Whitmore’s Timber - Claybrooke Magna) this afternoon to select a Walnut board for the rest of the Frame and Dial so I started to make some of the spindles, specifically those for the Escape Wheel and 2nd Train since they are both the same length but with a different shoulder to position the gears offset to each other. These need to be concentric so I can’t trust even a newly bored set of soft chuck jaws to hold true when they are reversed. Therefore the only option is to turn them between centres which eliminates all potential concentricity errors. I had all 8 spindles machined to length, centre-drilled each end and one end fitted to the 8 x 4 x 3mm Deep Groove Ball Bearings before going to Whitmore’s.

A vast selection of Superior Grade Black Walnut boards and the yard-man couldn’t have been more helpful in allowing me to see many before selecting what we each considered the best ---- or so I thought!! ---- everything went well and he even pointed me to their ‘offcuts’ section where I found a 1.2m length of 8 x 1 Canadian Hard Maple @ £15. Took a while to deal with paper-work and payment but I was on my way less than 40 minutes after arriving. Only when I got home did I actually measure what I had  

Neither he nor I used a tape measure, I just accepted what he said was a 6" board - it turned out to be a 5" board - actually 130mm wide but unfortunately just not wide enough to get my cutting list out of. Another 10mm and I might have been able to re-arrange the cutting up. So I now have to return it on Monday to select another. 

So, back to the spindles - mind you, I can at least have a go at the Maple over the weekend to see whether my concerns over the grain direction are really worth the hassle of making 10/11 segment composite Gears.

The Escape and 2nd Train Spindles are now done - Fig-76 shows them comple


te with the bearings.

*17th Oct*
With the Walnut not available and the spindles made, I thought to make the 8T Pinion which goes on the same spindle as the Escape Wheel.

As all the pinions will come from the same 10mm thick Maple stock, it made sense to set them all out in one drawing so that there would be minimal waste due to having to provide clamping holes, and, after a couple of attempts I finished up with the layout in Fig-77 where I’ve separated the four different Pinions by applying a colour. Combining all four meant that I had to think carefully about the depth of cut when creating the G-Code and the order in which each MOP should be made but that’s nothing new.

I was also aware that these small components also had quite delicate 1mm thick walls which, when assembled (glued in), would be perfectly good but in isolation may well prove an issue so I made the ‘finish’ cut on these parts 0.2mm. The fact that I’m using a 1mm Ø cutter for the finish also had a bearing on that decision!




I’ve learned a little about how Maple handles when cut with an up-cutting end-mill - it leaves ‘whiskers’ which need to be removed by hand, well riffler file - I may have to make another two, if so then I’ll change the cutting order so that the surface is removed after the teeth have been cut, that should eliminate the clean-up, though the reasons for cutting the surface first was to make the depth of cut short enough to be covered by the flute length of the 1mm end mill (and that is still a valid reason) so there may have to be a two stage process where most of the waste is removed leaving a ½mm for a final cut.

Because the Gears are 5mm thick and the 8T ones have a 3mm boss there was at least 2mm and as much as 4mm to clear from the opposite side of the blank so it was always going to be necessary to turn the billet over. When I designed the G-Code, I made a point of creating a Pocket MOP to deal with this but still leave a 1mm bridge between each Gear tooth and the main body. Fig-78 is after the second operation with the gears still held in place but machined to the correct thickness. Most of the Pinions could be broken out but I did need to cut through some of the Maple with a Jeweller’s Piercing Saw.




​


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## donwatson (18 Oct 2020)

Thanks again JG. This is absorbing reading and a very good example of a true WIP.


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## J-G (18 Oct 2020)

Thanks for that Don. If I didn't write it up 'on the fly' it would never get written. 

Here's a tale of caution that went wrong. I'll add it to the next .PDF but while it's fresh in my memory it's worth noting.

While the Pinions were being cut I got on with making the 1st Train Spindles. They weren't finished yesterday so didn't get a mention but I did continue with them this morning. Again turning between centres and, due to their length and the fact that they have a 3mm Ø section, I had decided that I needed to be cautious about the depth of cut --- that was until it seemed to be going so well that I got 'greedy'  D'oh!!


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## donwatson (19 Oct 2020)

Oooooppppssss


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## J-G (21 Oct 2020)

*18th Oct*
While the Denford was cutting the main 72T Drive Gear I re-made the fourth spindle. Before that I took a 310mm length off the Maple board and split that down the middle (ish) - at 150mm+ wide I’ve discovered that there is no way I’ll get three blanks out of the 27mm thickness, particularly since the saw cuts on the face are about a mm deep, so I’m resigned to having to skim at least 2mm off both faces.

As I anticipated, there is some break-away on some of the tips of the teeth due to grain direction but I can’t tell yet whether this will impact upon how the clock ‘works’. At 148mm Ø the 72 tooth Gear (Fig-80) is the largest and is the main drive wheel – ie. it is attached directly to the weight-cord winding bobbin. I had some difficulty with my initial plan to finish cut the teeth with a 1mm Ø end-mill since the flute length on that is only 6mm and this Gear is 8mm wide but to make sure the tooth width is covered I’d written the G-Code to cut 9mm deep. 
In the event, I changed that to 6mm and created another MOP to use a point 8mm ‘burr’ for the last 3mm. Once the Gear had been cut, I turned the blank over and cut most of the excess Maple away using the surface MOP, well until the Gear was close to finished thickness - sufficient to break away the waste anyway - the final thicknessing was done on the lathe as was the final sizing of the bore and the clearance recess for the Ratchet.



I’ve included the 8 & 10T Pinions in Fig-80 to show the relative scale of each but it also shows the difference between the ‘white’ Maple I bought a while ago and the Canadian Hard Maple I bought with the Walnut last week.

*19th Oct*
I cannot praise Whitmore’s Timber highly enough for their service, (their paperwork processing is a different matter!) I returned the 5" wide board this morning and came away with a 9½” wide board as a direct replacement since that was the nearest they had over the 6" I’d paid for. The nett result is that I paid ~£85 cu/ft rather than the ~£140 cu/ft anticipated. With a second visit I also cemented some connections, building a useful relationship for future purchases.

Now I have the Escape Wheel, Pinions and some spindles made, and, after cutting the Maple board for the Main Drive Gear, I have a suitable ‘stick’ from which I can make the spacers. While cutting that up to make blanks, I also made blanks for the Winding Drum because there were oddments of Walnut, Oak and Ash laying about that were of a suitable size so Fig-81 gives you an idea of how these small items start life and Fig-82 shows the three stages that lead to the finished spacers which go between the Escape Wheel and an 8T Pinion.




 . . . . 




Tomorrow I should start cutting up the Walnut board to make blanks for the Dial but I suspect that I’ll start by finishing the spacers and winding drums.
*
20th Oct*
As anticipated, I pressed on with the Spacers & Winding Drums, what I didn’t expect is that it took me all day!

I’d forgotten that I needed two sets of spacers - one at 16mm & another at 14mm wide - and there is another part (a Boss for the Winding Spindle) which looks similar to a spacer and is on the same page so I made those instead of the second Spacer.  When I came to the Winding Drums, I machined the one end and decided that trimming the excess length that was needed as a means to hold the blanks in the lathe chuck would be better removed on the band-saw. Regrettably I was somewhat cavalier (read stupid!) in my regard for that machine and had a bit of a ‘nasty’ resulting in one of the part finished Drums flying off to somewhere in the workshop yet to be discovered, I know it flew past my right shoulder towards the Jewellery bench but I didn't see it land and it could have bounced anywhere.

Having spent far too long searching for the lost part I took the pragmatic path and found another piece of Walnut to start again. The second operation of the Drums wasn’t without it’s ‘challenges’ either. Whilst I do try to be very detailed with my working drawings there are times when I leave out ‘obvious’ or non-critical dimensions and in this case that became a ‘pot-hole’. Working out a dimension for the overall length of the Drum in my head, I failed to take account of the collar thickness so I finished up 3mm short. This made me review the General Assembly drawing - to determine if it really mattered - and since that was only on the PC in my office, I spent some time doing a physical printout -- at 85% size -- on 20 sheets of A4 which needed to be trimmed and stitched together - Fig-84. It was my original intention to pin it up in the workshop but at over a metre wide and high that’s a lot of wall space! _though I may be able to fix it to a batten and hang it on the open door._ Not that I will need to review it that often - the design is pretty much ‘in my head’ due to the time I spent at the drawing stage but there are over 150 components so the nitty-gritty detail does occasionally get blurred.




 . . 




In Fig-83 I’ve assembled a selection of the Winding Drums - to show both ends and also with it fitted to the Ratchet - along with the Boss (which will eventually have a brass sleeve) and a Spacer with 8T Pinion attached.

I still need to do further work on the drum to cut the Cord fixing hole and I have to make the matting piece which turns it into a ‘bobbin’, so I won’t get to cut the Walnut up today, and maybe not tomorrow. At least it is acclimatising and could well do with a few more days to settle the MC after being stored outside, under cover but not ‘In Stick’. I don’t have a moisture meter but the board did ‘feel’ somewhat damp so that may well be the reason I seem to be procrastinating.

Can't tell why but the PDF file refuses to show any text if I put two pages together so there are two separate pages to WIP-15.PDF (attached) - I had a similar issue with WIP-7.


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## donwatson (22 Oct 2020)

Thanks again JG. Looks like you have lots of problems with these pieces but seem to resolve them pretty quickly.


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## J-G (22 Oct 2020)

I suspect that I don't have any more problems than anyone else but because I'm writing this up as a diary, I record the issues as they arise whereas with a WIP written up after completion the problems get forgotten.

All problems are down to my own ineptitude and I don't find need to hide that since the whole point of a WIP (in my opinion) is to highlight what issues may come up in a 'fore warned is forearmed' attitude.


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## donwatson (23 Oct 2020)

I agree with sentiment.


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## J-G (23 Oct 2020)

*22nd Oct*
I’ve done nothing on the Denford for a couple of days so nothing more to show as far as gears or frame are concerned. I still haven’t started on the Walnut plank - but I have been thinking about the potential issues - mainly due to the problems I had cutting the Maple down the middle of the 27mm wide board.

I’m thinking that I’ll need to break out the Table Saw rather than hope that the Band Saw will behave. That will mean that the kerf will be about 3mm rather than ~1mm so I might have to re-think my cutting regime. Since the board is 9½” wide that won’t matter but it is a large lump and having another pair of hands on it will certainly be an advantage so I’ll probably make a start on it on Sunday when my grandson should be available.

The winding spindles are now made - well the turning part is done - they still have to have the square for the Key and the locking flat milled, and I’ve tentatively assembled the Escape Wheel/Pinion/Spindle together and tested how that aligns with the Latch/Finger/Pendulum as seen in Fig-85. I’ve attached the 1st & 2nd train spindles but the Gears for those aren’t made yet so that is my next task.





There are two gears on both spindles, a 32 & 60T on the 1st and a 64T + 8T Pinion on the 2nd. For a number of reasons I’d cut part of the Maple board down to 132mm wide so could get all the 32T gears out of a 340mm length of that but the 64T needs just a little wider to make sure that there is no ‘trimming’ of some teeth. This made me settle on creating the G-Code for 8 - 32T gears first and I needed to split the Maple down the middle which didn’t go as well as the first time. Hard Maple really is ‘hard’ - beautiful but challenging! Even with the Band-saw tension set for a 1" blade rather than the 3/4" I’m using the cut wandered over 5mm across the 132mm width after 200mm length so I started again from the opposite end but it took some effort to separate the two halves. 

I might retrieve the second piece and make two 60T gears from it but first I had to machine the first half to get it near parallel before mounting it on to the Denford table. It still needed a 3mm cut before the surface was clean though. In Fig-86 you can see that it’s finished up at about 9mm thick and it’s interesting to see a dark streak which is totally enclosed - not that it matters, it’s a natural product, and just adds character. The gears will be 5mm thick finished so there is enough timber available to not need a sacrificial sheet and once the gears are cut to 6mm deep the board can be turned over to have the second face machined leaving small tabs holding them in place to be sawn free in a third operation. This may not be possible for the 60T gears I hope to get out of the other board.


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## donwatson (25 Oct 2020)

Thanks JG


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## J-G (27 Oct 2020)

My workshop time over the weekend was restricted due to F1 & Strictly  . . .  but I did get some work done.
=====================================================================
*23rd Oct*
The drawings for the 32T gears were done a while ago but this morning they were still in CorelDRAW! I’m pointing that out only because it astounded me that I hadn’t created the G-Code and sent it to the workshop until mid-afternoon. It’s astounding how long it takes (me) to arrange multiple identical items on a grid to allow for minimal tool clearance and avoid clamping holes!



Maybe I’m being too ‘tight’ in trying to squeeze the most out of any piece of timber and not considering the time element as part of the cost....... hmmmm.

I’m finding this Maple to have a mind of its own! As you see in Fig-86 the blank was screwed down and flat against the table but, after the outline of the gears had been cut, the ends had lifted up by 2 - 3mm so before I did the finishing cuts I needed to use another 4 clamps to make sure it remained flat. I didn’t need the clamps after turning it over and the trimming of the backside made it easy to release all eight with just a few strokes of my piercing saw.

There were periods of 40 - 50 minutes where the Denford simply got on with following the G-Code paths so I used that time to mill the flats on all the spindles plus drill & tap the Winding Drums.

Finished the day by cleaning the 32T Gears to 5mm thick on the lathe - I still have to machine the recesses to take the spacers but I thought 11:30pm was quite late enough to be in the workshop! I suppose that Fig-88 is not a bad days work though, even if most of it was done previously 



*24th Oct*
Finally! - I bit the bullet and broke out the Table Saw to cut up the Walnut board. My original plan was to simply cut the 9½” wide board down to just over the 6" that I needed but after looking at the options decided that cutting a 700mm length off, that would be easier to handle than the 2.2m long board. It meant that I wouldn’t be left with a 2.2m length of 3 x 1½ Walnut which might become useful for some future project, but considered that a small price to pay for the convenience of handling a smaller ‘lump’. In a similar fashion I then cut another shorter length, enough to cover the next set of parts and so on. 

Although most of the frame components finish up at 10mm thick I’m only taking two pieces out of the 42mm thick stock at 15mm each and to ease the burden on the band-saw I’m starting the thicknessing on the table-saw by cutting 1/3rd of the depth from each side and then finishing the split on the band-saw. The parts for the Dial are more of an issue. They finish at only 5mm thick so I’m hoping to get 4 ‘slices’ out of the 42mm. With a 3mm kerf that could be challenging so I may attempt to try it on the Band-saw but that may not like an 80mm wide cut.

Time ran out on me today since I had other chores to get done but I hope to have all 50 blanks ready for their next operations before Sunday is done.

*25th Oct*
I thought I’d completed the ‘slice-n-dice’ this morning but when I stacked and labelled what I’d got there were only 48 pieces and I expected 50 ------- it took me some time to work out what was missing and I discovered that I’d missed one item off when I created the cutting list so in reality I needed 56 altogether. Fortunately there is plenty of spare so the extra 8 were soon sorted.


The facts that the Band-saw was causing me some grief and I really needed it to play ball when I was cutting the slices for the Dials made me spend some time looking for the problem.

I had fitted a new blade less than a fortnight ago but I did have another on the shelf so that was certainly worth fitting. More important was the fact that I couldn’t move the guide assembly down to just clear the work so that meant a major dismantling of the mechanism. It’s a very questionable design since the only way to get it off the saw is to drop it to the lowest level before removing the top wheel, but since saw-dust can (and does) get into the Rack & Pinion jamming it up it’s impossible to get the wheel off. I had to trim part of the structure away so that it didn’t foul the wheel. Even then it is very tight against the top wheel casing needing a specific orientation before allowing the clamping stud to go through the clearance hole. Drilling that hole out to 11mm rather than 9.5 made all the difference.
With the new blade in place and the guides at a new low, cutting 8mm thick slices for the Dial, whilst not a ‘breeze’, was certainly much easier with little to no ‘wander’. I had been taking it very slowly (specifically with the 150mm wide Maple) but actually found that a firm ‘push’ improved matters.
*
26th Oct*
Naturally, cutting the Walnut board into the basic sawn blanks for the Frame, Dial & Wall Plate is only the start of process and since my Table Saw is not an industrial Wadkin or similar I needed to make sure that the edges of these blanks were square to the faces so that when clamping them in the ‘vice’ on the Denford table they wouldn’t tilt - I’d made a decision that to skim the surface it would be better to clamp them by the edge rather than drill recessed holes so broke out the eccentric clamping block that came with the Denford. This meant that all the blanks now needed to have the edges cleaned up on the Router Table. 

It also seemed sensible to fix a piece of scrap to the table and machine the face of that to a specific point for each component and Fig-90 shows both the ‘Stop’ and the clamp.





As I don’t have a belt sanding thicknesser and most of the blanks are only just over 200mm long - too short for a P/T but too long for my mill - the surface needed to be cleaned up on the Denford. Starting with a blank for one of the side spurs of the Frame I soon realized that it would be most efficient to clean the surface of all of these blanks before moving on to cutting the outline and joints.

Cleaning up 16 blanks with each pass taking only 2 minutes meant that I couldn’t just leave the Denford to get on with it so I only got to cut the first outline and joints on the first blank quite late in the day and I forgot to take photo’s before I’d done two! The prepared blanks are stacked in Fig-91 and the first strut with joints cut in Fig-92. I still have to turn that over to cut a recess and finish the surface to 10mm thick.


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## donwatson (28 Oct 2020)

Whew !! Things are moving along. Thanks again.


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## J-G (29 Oct 2020)

*27th Oct*
Today’s been a bit fraught with the Denford trying to make me respect it more  The four rear right struts are cut out to depth and the first of those has been turned over and machined down to just over the finished 10mm thick. My first attempt at skimming the second face had to be aborted because the clamping mechanism I thought might work wouldn’t hold the part finished item flat so I had to resort to drilling and counterboring holes to improve that - or rather make it possible - by screwing the part finished blank down. Fortunately I found three places where I could align the holes with the 40 x 40 grid of holes in the Denford table but unfortunately when I got close to the final thickness, a part of the blank began vibrating causing some chatter tool-marks to appear. Not so much that they can’t be sanded out but enough to make me look at finding another clamping hole. I can’t show an image since my phone/camera can’t see the damage - I might try using an endoscope tomorrow to see if that will pick it up.

The annoying part is that the next operation - cutting a recess - had to be abandoned. At least I can take comfort in the fact that this is exactly what the project is about - finding out how to handle materials in a CNC environment.
*
28th Oct*
Having slept on the problem of the uncut recess, I think I can solve it by re-designing the G-Code. The issue is that the depth of the recess has to be 3mm from the top surface and although the blanks are all about the same thickness the potential .2-.4 mm difference does matter so that was the reasoning behind trimming to the final thickness first but in fact if I use the table surface as the datum, then I do know that the recess must also be 7mm from there. So, I can set the G-Code to cut a recess stopping at +7mm from the table rather than what I currently have which is -3mm from the top surface - the end result will be the same.

This tactic also obviates the need to use the 40 x 40 grid holes to hold the parts. The part finished one can be positioned just as easily as the other three. Once the recess has been machined on all four I can go back to the surfacing operation using the clamping holes including the one which has been recessed though that won’t be on the grid so will need a wood-screw into the table which won’t matter a jot.

Having cut the recess I took a photo’ to show the clamping strategy but then thought that I could also try-out the endoscope to see if that would pick up the ‘chatter’ damage. It took a while since I had to install first Zoom, to give the Endoscope somewhere to display the image, and then Photoshop so that I could display the screen-grab.

As it happens, the chatter damage can be seen on the Phone Photo’ (Fig-93) but the Endoscope image (Fig-94) makes it more visible.









The four Rear Frame E Struts are now both recessed and skimmed to just over the 10mm finished thickness and I’ve started on the G-Code for the Rear Frame ‘C’ strut which is the opposite side. Having found that clamping down to the table via the grid of threaded inserts is necessary I’ll include the clamping holes in the G-Code and, bearing in mind the ‘chatter’ problem, modify the [Holding Tabs] from the 3mm x 3mm triangular default to 4mm x 4mm and square which will give a stronger hold for the second side machining. I’ll still have to cut the counter-bores as a second operation on the mill since they have to be from the side that is against the table but the positioning of the screw hole will be accurate and the counter-bore is by definition oversize and not critical.

Although I have the blanks for the Front Frame C & E struts prepared, I think that it will be better to prepare the blanks and finish the Rear Frame D extension first which will mean that I can get the whole Rear Frame put together.


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## donwatson (29 Oct 2020)

Thanks JG


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## J-G (1 Nov 2020)

What a morning!!! I did some work first thing and updated the WIP with the intention of posting it at about 10 o'clock. First problem was that my PC wouldn't allow me to create a .PDF file ??? The printer selection kept reverting to the physical printer which is the first in the list but not the [Default].

It seemed that a keyboard key was stuck because, when I tried to remove and re-install the .PDF Printer Driver, the file listing kept moving to the top of the list ??? Eventually traced it --- after closing all the open programs and re-starting the PC - twice!! --- to the wireless mouse/keyboard USB receiver which I removed and re-inserted and that sorted the problem.

I've been building PCs and providing support for over 30 years and never come across such a silly issue before.

I still had some issues with the .PDF losing some text so had to do two separate pages.

2 hours later and I can start to transfer the latest installment!
============================================================================
*29th Oct*
Having done all the transfer of CorelDRAW! drawings of both sides of the Rear Frame ‘C’ strut to .DXF files I soon had the G-Code files ready and could let the Denford & Mach3 get on with machining them while I got on with other small items such as spacers on the lathe. I had to keep checking the Denford to change tooling of course but I was able to sort of multi-task.

All went well for the first strut but just after one pass cutting the outline of the second I was aware of a change in the sound - even though I don’t make a point of listening to one machine doing its own thing whilst I’m working on another, the natural instinct is to be ‘aware’. The change came about because the 3mm cutter - a cheap single flute TCT item - had broken off just below the shank  ie. no cutting edge at all. This was a 1mm deep cut in wood so no real stress. Not having another 3mm router bit I had to re-jig the G-Code to use a 4mm.

The next problem arose when I left the Denford machining the last blank while I had a bite to eat. You can imagine my dismay when I got back in the workshop to see that the blank had moved about in the X axis due to being just a little narrower than the other three and not being held as firmly. ( I became complacent!!) A piece of thin card soon sorted the clamping out but I had to guess at the precise lateral position and although I did complete the remaining oper


ations I won’t know if the strut can really be rescued until I come to fit it to the rest of the frame. Fig-95 shows the damaged strut at the bottom and compare it with a good strut at the top. If I can make it fit then I’ll still have to ‘bodge’ an in-fill to repair the damage. The lesson learned is that I must also clamp in the X axis.

Other than that, I have the spacers made for the 32T to 60T gears (though not the 60T Gear yet) on the spindle which will also carry the hands. The hole in the spacer needs to be a good fit on the 6mm spindle to maintain concentricity so it was drilled out to 5.5mm and then Reamed to 6mm.

Because these spacers are


made from Maple, I anticipated that even reaming them might leave them ‘tight’ due to wood fibers swelling so I put the reamer in the lathe head-stock so that I could re-ream from both sides - working the spacers by hand until I got a good press fit on the spindles - that way the wood fibers were cut from both directions thus minimizing any tear-out.

I still have to ‘finish’ the teeth on the gears but that is going to be an intensive ‘hand-work’ job for which I think I’ll make a ‘frazing stick’ with 320g abrasive.
*30th Oct*
This morning I’ve completed the second side of the ‘C’ struts which gave me little time to work on the smaller parts which have to be done on the lathe but I did get the motion works spacer started before returning to the ‘D’ section of the Frame, specifically to machining the blanks to an even thickness. I’ve now realized - because I started to create the G-Code - that I’ve prepared the Front ‘D’ frame rather than the Rear. No big deal since both have to be done anyway but I was working on the Rear Frame, so I’ll create the G-Code for both before getting back in the workshop to prepare the Rear ‘D’ blanks.




Not a brilliant photo’ (Fig-97) but you c an see that the Frame ‘C’ strut has held together due to the wider & higher Holding Tabs and that the Rear ‘D’ blanks are taller than the Front ‘D’ blanks. The only difference between them (at this stage) is the width. The Front one has to take a larger bearing so is 42mm wide whereas the Rear is only 32mm. Ultimately the difference is also that the Front D Frame can have the joint and the bearing recess machined from the same side but the Rear D has to be turned over to cut the recess so I need to take care when selecting the position on the table. That difference made me realize my error.

A number of issues about work-holding came to light when creating the G-Code and it would probably have been better to leave the Walnut for the ‘D’ section of the Frame in one length rather than cut to individual blanks. Hindsight is a wonderful thing  Tomorrow I’ll have to see if I can machine the Frame D parts with just clamping in the Y axis as opposed to screwing them down.

*31st Oct*
The Rear Frame D sections are now all ‘thicknessed’ using just the eccentric clamping jaw. They cleaned up at just under 13mm (the Front Frame version is just over 14mm) so the G-Code has been adjusted so that I don’t cut into the table.

I’ve been cautious about using a 2mm burr to cut the outline due to the 11mm depth but since the 3mm TCT cutter broke leaving me only a 4mm option which I considered too wide for this part, I decided to specify it when creating the G-Code but I reduced the depth of cut to ½mm rather than 1mm which I’ve been using for the ‘rough’ 


outlines with the 3 or 4mm TCT cutters. I also specified the 2mm burr for the finish cut since my 1mm spiral flute cutters can only reach a depth of 6mm. The only problem with using burrs instead of spiral flute cutters is that they leave ridges. These will be removed when I do the finishing process through the abrasive grits of course.

As you can see from Fig-98, I’ve re-thought the clamping methodology and made specific width spacers to achieve a good grip but also restricting the blank in the X axis as well. Using this method also affords me the opportunity to cut the joint on all four blanks before changing the tool to cut the outline or drill the hole. Previously I’ve kept the blank in place and changed the tool for each operation before starting again with the next blank. For this particular part that would have meant 12 tool changes rather than 3, so overall quite a bit more convenient and faster - not that I’m too concerned about speed of manufacture.

Machining the outline was taking 15 minutes so there was time to do other work on the lathe 


and I got all the Beech bushes for the motion works made though not the brass bushes which will provide a ‘free running’ bearing for the hour hand.

Because I had no means by which I could screw the ‘D’ blanks down to skim the second side, I had to use a clamp at the right hand end. I was well aware that I couldn’t run the fly-cutter straight across the blank so when I created the G-Code for the surfacing I made sure that it stopped short of where the clamp would be. That would be all well and good as long as I also made sure that I positioned the blank in the correct position on the table. The adage of “measure twice and cut once” comes to mind here!!




What I actually did with the first blank was position it 40mm (one grid hole) too far along the X axis. I should have done a ‘dry run’ by cutting air but unfortunately just watched as the Fly-Cutter ploughed straight into the clamp and broke both carbide bits  Fig-100 is the remains of the carbide cutters retrieved from the cutter block. See WIP-3 Fig-12 for the cutter block itself. As it happens I use - _and break_ - quite a few 1/8" Ø solid carbide drills so I have a stash of spare ‘shanks’ so it only took me 10 minutes to replace the bits and sharpen them.

*1st Nov*
I’m somewhat surprised this morning to find that the blank _*is*_ in the correct location on the table ????

This means that I had to look again at the CamBam parameters/drawing and it turns out that I had drawn the engrave MOP line just short of the furthest extent I wanted to cut to rather than to the radius of the cutter - D’oh!!




In Fig-101 you can see the damage the fly-cutter did to the clamp and the Rear Frame D machined to 10mm thick as far as the cutter needed to go.
It also shows the ‘holding tabs’ which keep the integrity of the clamping sufficiently to take surface skimming cuts - I tend to keep them under 1mm deep.


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## AES (1 Nov 2020)

EXCELLENT WIP J-G, thanks. I'm really enjoying this, thank you very much Sir! 

While definitely NOT wishing to gloat ('onest Guv!) being a definite PC klutz myself I was heartened to read that the experts have "funny PC problems" themselves from time to time.

Keep up the good work please - I know myself how much time and effort goes into producing such posts.

All the best.


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## J-G (1 Nov 2020)

Thanks AES - it's difficult to know how useful - or simply 'interesting' - a WIP is when there is little feed-back so yours is much appreciated.

Being able to solve PC problems is often down to having experienced the same (or very similar) problems yourself and most of my customers know me because I've suffered the same issues - and sorted them - in the past. It's very much a matter of following the 'logic', - after-all PC aren't sentient no matter how often it seems that they have their own agenda


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## AES (1 Nov 2020)

J-G said:


> Being able to solve PC problems is often down to having experienced the same (or very similar) problems yourself and most of my customers know me because I've suffered the same issues - and sorted them - in the past. It's very much a matter of following the 'logic', - after-all PC aren't sentient no matter how often it seems that they have their own agenda


 

Thanks J-G, glad to offer "encouragement" 

Re your comment about PC's (quoted above), sorry but you're quite wrong you know - ALL my PCs most definitely DO have their own agenda (or perhaps better said, "that young Mr. Gates and his merry band of brigands do"!!!!!!!!!!!


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## J-G (2 Nov 2020)

Starting to see some progress now that I have a Frame 'Dry assembled' so here is the 20th installment!
==============================================================================

Once I’d finished the Rear Frame D struts it made sense (to me anyway) to work on the FRONT Frame D struts since they were already prepared by having the surfaces skimmed and they would be easier than those for the Rear Frame as the recess for the bearing is on the same side as the joint so there was no issue with re-positioning after turning over. It still took me the rest of the day to get just the one sid


e done due to other commitments! — and even then I’m not satisfied with the result. You’ll see in Fig-102 that I mis-judged the position of the blank on the Y axis by about 1mm. Fortunately the diameter of that section is not ‘critical’, 40mm was just a convenient number I came up with so I can quite easily create another MOP to cut it down to 38mm.

The only other part I’ve done any work on today is the 10T Pinions used in the Motion Works - the start of the train that takes the hour hand rotation and speeds it up to drive the minute hand - I thought I’d done all the work on these but I’d been less than explicit when I did the technical drawings and I mis-read a 12mm x 1mm [Slot] as a 12mm Ø [Recess] so that needed to be addressed. These 10T Pinions fit on the main spindle but in front of the frame and pass through a needle roller bearing. They are drive


n by a 1mm Ø pin which fits in a cross-drilled hole in the spindle – which I can’t drill until such time as I have both Front & Back Frames fitted together – and that pin sits in the slot. The recess I cut in error won’t matter because it will be behind a larger gear.

In Fig-103 you can see the slot in the stacked pinions and the recess in the pinion on the spindle. There is also a slot in the single pinion but it’s difficult to see.

*2nd Nov*
Doing the 38mm Ø trim on the Front Frame D strut has taught me that I don’t need to do both roughing and finishing cuts with the 2mm burr. You’ll see in Fig-104 that the finish straight off the burr is very good indeed - though trying to photograph the ‘ribbed’ finish is not easy - 


this is on the straight sections which were cut with a ‘finishing’ cut of only 0.3mm but the main reason for the ribbing is down to taking a 4mm depth of cut. This would be fine if I were using a spiral flute cutter but I suspect that the ‘burr’ has a 1mm pitch and the ‘teeth’ are not cut on a helix so it is effectively a ribbed cutter. The trim to 38mm Ø on the round section was done with a 0.5mm depth of cut which I presume gets around the burr ‘pitch’.

Now all the rear frame sections are cut out I spent the morning breaking away the waste, removing the holding tab left-overs and dry assembling the parts to check that there are no major adjustments needed. I’m well pleased with what I found. The C & E struts all went together with just a little hand pressure. The D strut is an ‘easy ‘ fit and that is - if anything - a benefit since it will allow me some tolerance in the positioning of the winding spindle bearings which can only be finally fathomed when I have the two frames fully assembled and the main spindle in place. I’ve annotated Fig-105 to give you a better understanding of how I referenced the struts. I


’ve also shown the frame with the brace made from Maple which again fits very snugly in place - ultimately it will be glued both to the rear frame and also to the spacing pillar at its foot which will hold the front & rear frames apart.

I did find one small error though. For some peculiar reason when I made the ‘A’ component I cut the main spindle bearing recess 8mm deep rather than 3mm ??? - 8mm is correct for the FRONT frame which has an 8mm long Needle Roller bearing but the Rear Frame has a 3mm thick deep groove ball bearing.

This meant that I had to make some 8mm Ø x 5mm long plugs which I did from some of the Walnut scraps.


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## donwatson (4 Nov 2020)

Thanks JG. I am having some PC problems at the moment but they should be easily cured.
Don W


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## J-G (5 Nov 2020)

*3rd Nov*
A busy and interesting day with a few mistakes made & corrected. It started when I picked up the sawn blanks for the Front Frame ‘A’ section and began to think “Why did I need to saw these at 15mm thick when they will finish at only 10mm?”. This question was answered some time later when I realized that I’d created G-Code to cut both joints 5mm deep when in fact one of them should only be 3mm deep. Not only had I created the G-Code, I’d actually cut all four before I realised  

This meant that I had to trim 2mm off the face and then re-cut the one joint back down to 5mm. Re-positioning wasn’t a problem with that last one which I hadn’t dis-mounted but the other three did need careful attention to make sure that the width of the 5mm deep joint wasn’t increased.

The fact that I’d (unusually for me) allowed a 50% waste factor saved the day but it took me all day to recover the error and I eventually completed the four Front Frame ‘A’ sections just before midnight — I had taken time out to eat though 

I was hoping to get the frame spacers turned while the Denford was busy and I did at least get some Maple sawn to 18mm square and used the Router Table to round the corners so that I could hold the blanks in a 20mm collet chuck. Turning them down to 16mm Ø and drilling a ¼” Ø hole will be a job to do the next time the Denford is tied up.

*4th Nov*
I hadn’t finished the Front Frame ‘A’ section yesterday, because the cut to round the ends only went 1mm over depth so I still had to remove the waste and clean them up on the linisher.

For some time I’ve been concerned that I didn’t do a thorough job when I drilled the grid on the Denford Table since I only drilled the holes deep enough to take the threaded inserts and I’ve found that the M4 screws which I have in 5mm increments sometimes ‘bottom out’ before the work had clamped. I had been manually drilling the table deeper for the holes that I needed to use and then tapping them, but this morning I resurrected the G-Code which cut the grid and changed it so that all the holes were drilled right through the sacrificial table and left that running while I created the G-Code for the Front Frame ‘B’ section which will be the next part to be made. I’ll still have to tap each hole by hand of course but I can do that on an ‘as-I-need’ basis. At least I can’t make the same mistake as yesterday since all the joints on the ‘B’ section really are 5mm deep!

*OUCH!!!*

Well, I didn’t make this mistake! It seems that either Mach3 or the Denford decided that I was doing too well today having skimmed both surfaces of the Front Frame ‘B’ sections with nary a problem, and even cut the joints and two holes in the first blank whilst also giving my grandson instruction in the use of the milling machine during which time I just let the Denford get on with cutting the outline. I knew it was going to take a while since I’d decided to take just a single cut down to the 11mm depth in ½mm increments and I just kept an eye on what it was doing occasionally. All was going to plan and the depth was at about 8mm when I had to spend a little more time on the mill. The next time I looked at the Denford it was cutting the blank in half !!! - The drawing in CamBam, Fig-106, from which the G-Code is generated has no line going from top to bottom but that is what was being cut when I got back to checking the Denford – the result can be seen in Fig-107.
​




Maybe the Denford felt neglected  




I’ve poured over the G-Code and can find no error so therefore no reason that the Denford suddenly changed from following the instructions and simply moved the table along the Y axis, and since I wasn’t watching at the time I doubt that I’ll fathom what went wrong.

I stopped it before it had completely cut deep enough to sever the two halves and I suspect that I can glue in a 2mm thick piece of Walnut to recover it. The concern is that it will happen again on the next blank so I’ll have to watch every pass - just in case. It will be prudent to split the cutting of the outline into two sections, the first going down to (say) 8mm in 1mm increments and the second starting at 8.5mm, going to 11mm in ½mm increments. That will at least address the issue of the ribbed finish that the burr creates when using full mm pitch cuts and might stop a repeat ‘rogue’ cut.

After some deliberation - read :- ignore the problem and do something else - I switched the Denford off and closed Mach3, left it for a while then re-started both. The first thing that has to be done on starting Mach3 is to [Zero] the axes. This showed that the Axis registration was way out and I now suspect that the ‘X’ Axis motor or the ball-screw had jammed but the ‘Y’ Axis continued to operate.

I have plenty of thin sections of Walnut so it didn’t take long to trim a piece down to 2mm and glue it in to the damage and that is now curing overnight.


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## donwatson (5 Nov 2020)

Very strange behaviour indeed.


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## J-G (9 Nov 2020)

*5th Nov*
Re-created the G-Code for the outline in two parts and the first run of the 0-7mm deep code went exactly as expected. The depth of cut at 1mm was no problem and because the Y axis only cut must have been 8 or 9mm deep without breaking the 2mm burr I suppose that I could quite easily use a 4mm cut but I’m not yet confident enough to attempt that!

The main cause for concern is that I have no idea how the X axis lock-up happened so can’t tell if or when it might happen again. This means that I have to keep an eye on it rather than leave it working away while I do other work. Only time will tell and I’m sure that I’ll again become complacent and just get on with lathe work.

Not quite ‘complacent’ but I have been making the Frame Spacing struts which I started a couple of days ago whilst still watching the Denford. Rather than drive them with a Collet Chuck (they wouldn’t fit in the largest I have) I turned them ‘between centres’. A total of 12 ar


e needed (3 per clock) - 16mm Ø and 78mm long with a ¼” hole. There needs to be some small clearance to allow for minor adjustments and the clamping screws will be 6mm Ø with M5 threads on each end. I made 4 lengths at just over 300mm long so I could afford to grip the first 20mm in a carrier (Fig-108) and still cover the 3 - 80mm lengths.

The Front Frame B sections are mostly finished but I still have to create the recesses for the Dial Pads and for that I’ll have to make some positioning blocks so that I know exactly where the Dial Pegs should be. 

*6th Nov*
Serendipity reigns it seems because when I designed the Dial, I put the stand-off/location pads at 160mm apart which is a multiple of the 40mm grid spacing on the Denford Table so I can use the existing screw holes and just make locating pegs to fit the already drilled holes in the Front Frame B section. More than that, the head of a standard M4 Button Head screw is 7.3mm Ø and the holes I want to locate are 6.8mm Ø so could easily be turned down to fit the holes. Using CorelDRAW! it is a simple matter to draw two circles at 160mm centres, align them with the grid pattern and export a .DXF file ready for CamBam to create the G-Code to cut just the recesses. So no need for positioning blocks, I just had to put the B sections on the two machined screws and clamp them down.
Cuttin


g two recesses only took about a minute so there was no time to multi-task and finish the spacers but I did want that job completed so before starting the Front Frame C & E sections I spent some time on the lathe and completed the spacers. I‘d machined the one end and drilled through as a first operation but I had to trim to length by machining the other end and it seemed sensible to drill out this end to 7mm Ø to make sure that the 6mm shafts would have no prospect of ‘binding’ and even give me some room for minor adjustments in case that became necessary.

In Fig-109 you can see both sides of the Front Frame B section before I separate the component from the blank by sawing through the holding tabs. In the background are the Frame Spacers. The change from using the (CamBam) default holding tab dimension of 3 x 3mm Triangular to 4 x 4mm Square has made second operation surface skimming much less demanding

*7th Nov*
I thought the


Front Frame C section were going to be very straightforward since all the joints are on the same side so there isn’t a potential ‘alignment’ problem but in any case I’d decided that screwing a piece of scrap material to the table and cut it by CNC to exactly where the blank needed to be (Fig-110) gave me a very solid ‘Location’ clamp. I’d also written the joint depth on the drawing in CamBam to remind me that they aren’t all the same - however I hadn’t reckoned with the Denford wanting to assert it’s authority!

The X axis motion failed twice out of the four, causing some damage to one joint shoulder - the same joint in both cases. This may mean that I have to fit a small wedge of Walnut which will unfortunately be at the front but may be masked by the Dial - until I do the trial assembly I won’t know. In Fig-111 the lower component is good and you can see the damage in the top one. I suspect that there will be no more than 1mm taken off the shoulder which should be at a small angle (Green Line) but due to the X axis lock up has been cut square.





Naturally I have been investigating what might be causing this problem and have discovered that rather than the X axis motor or Ball Screw seizing up - which would be a serious issue needing difficult intervention - it seems that the X axis Stepper Motor Driver is switched off. I only found this out when I opened the back of the Denford to look at the ‘Electronic’ bits and in Fig-112 you can see that the middle SMD has no ‘light’ - therefore switched off. 

Turning the Denford Off and back On brings it back so it seems that it may be some sort of ‘overload’ protection might be being triggered but that is only a guess suggested by the previous owner.


I’m now looking at the precise point at which the Driver was turned off and suspect that it might be connected with the location of the [Holding Tabs]. Though why it doesn’t happen on every occasion is weird – inconsistency always defies logic and I may have to raise a question on the CamBam forum.

Due to these X Axis problems I can’t yet comfortably leave the Denford to get on with its job while I do other work on the Lathe or Mill so I’ve not done a lot of work toward making the clamping studs. I have done a little, but cutting an 8mm long M5 thread does take some time so only three have been done, though I have cut them all to the rough length.

*8th Nov*
Nothing whatever done today - it was spent creating a round for a ‘Zoom’ quiz session that I will be running on Tuesday evening.


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## donwatson (12 Nov 2020)

Thanks once again JG


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## J-G (12 Nov 2020)

I was beginning to think that you'd gone to sleep Don  the .PDF shows 0 views and I was nearly ready to post another installment at 2am but hadn't taken a photo so that will come within the hour.


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## J-G (12 Nov 2020)

*9th Nov*
Back in the workshop, but late so only got 3 of the 4 Front Frame E sections made and found that a 2mm solid carbide burr can be crushed to breaking point by the power of a stepper motor. Good job it broke really, otherwise it may well have punched a hole in the Walnut blank  As it happens I had two spares so I was soon up and running again. You can see the relative size of the two cutters in Fig-113.




I’m still trying to understand what I can get away with as far as feeds & speeds are concerned and for this operation (cutting the outline) I’d increased the depth of cut by 50% to 1.5 mm – to some extent this was prompted, not by wanting to increase work throughput, but to get a clean face with the burr and avoid the ‘ribbed’ face created when using a 1mm DoC. It is removed with a ½mm DoC but that doubles the time taken. The next operation needed the 6mm TCT cutter and the G-Code for that was created with a 1mm DoC and it suddenly occurred to me that if the 2mm burr could handle 1.5mm DoC then the vastly more robust 6mm tool ought to handle 2 or even 3mm DoC. It’s a pity that I didn’t realize this earlier.

On further consideration - _can you tell I’m ‘thinking on my feet’?_ - the DoC that can be taken is not just dependent upon the strength/robustness of the cutter but also the ability of the work-piece and clamping mechanism to withstand the forces........

*10th Nov*
The second side of the E section is now complete - though I haven’t loose assembled them - so I’ll move on to the Wall Plates. No ‘Joints’ or curves involved but they do have to have pockets and recesses for the Brass ‘Key-hole’ plates, and just for the appearance they need to be chamfered all round - which could very easily be done on the Router Table but the challenge of doing it via CNC is interesting.

I said that there were no ‘curv


es’ on this part and that is true of my original design but when I got the first blank on the Denford I realized that it would be very easy to round the corners off and also have a pleasing chamfer following that curve as in Fig-114. To do that by hand or even on the Router Table would have been much more difficult to get right.

Yesterday I remarked about increasing the DoC with larger cutters and the Wall Plate was cut mostly with 4 and 6mm Ø tools with a 2mm DoC - easily handled - the chamfer was also cut at 1000mm/m feed. That compares to the 400mm/m I’ve generally been using.

*11th Nov*
It was my intention to do some lathe work today but realized that I had to skim the other side of the Wall Plates first and then got to thinking that the chamfering had been easy, so I looked at the Wall Pad which is just a 20mm Ø x 4mm thick ‘button’ of Walnut which will act as a wall protector for the vertical adjustment screw which also has a chamfer. At that size and needing to be ‘face grain’ rather than end grain it is an awkward piece to hold in the lathe but all four could easily be made from a Walnut scrap/offcut - and I have plenty of that!




I did finish the 8 Frame Clamps on the lathe while the Wall Plates were surfaced and then set about the G-Code for the Wall Pads and the Wall Spacers - these hold the Steel Buttons which fit into the Brass Key-hole Plates and would similarly be awkward to mount on the lathe - and it is much more material efficient to make by CNC.

Whilst the outline of the Wall Pads were being cut I started on the Brass Cups which fit in the two fixing holes in the Wall Plate (Fig-114) I only got 6 made so the other two will be done tomorrow, along with the Spacers and Steel Buttons.


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## donwatson (13 Nov 2020)

Thanks again JG. Will have a look later when I have been to the wood store.


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## J-G (16 Nov 2020)

*12th Nov*
I seem to have done a great deal today - but little ‘CNC’. It’s interesting to realize (though I always knew it to be true) that selecting the best method of manufacture is not always obvious. Before I had the Denford if I needed a round wooden object with the grain running across I would automatically cut a square piece - maybe cut the corners off to make it octagonal - and mount it in a four jaw chuck. Having now made the Wall Pads and Wall Mounting Spacers from Walnut off-cuts by drawing them in a ‘staggered’ layout, it makes more sense to do this type of part by CNC - even for a one-off - (though naturally multiple identical parts benefit more) due to the ease of work-holding.

Having finished the last two Brass Screw Cups first operation, I re-mounted each and finished them to thickness and loosely fitted them to the Wall Plates. As I had the 10mm Ø Brass bar to hand, I then made the Vertical Adjusting Nuts. Although they are ‘nuts’ they are 10mm Ø but will be fixed into Walnut spacers with Epoxy. This is better than putting a thread in Walnut end grain even though there is unlikely to be much ‘Adjustment’ when in use - it is just there to take account of the wall (which the Clock is hanging on) not being truly vertical. The Spacers which these fit into came out of 25mm square stock held in a four jaw chuck with a live centre support. 




In the meantime, the Denford had finished the Wall Mounting Spacers - well as far as could easily be done using CNC - so they could be mounted in a pre-bored chuck on the lathe where they were drilled and counter-bored to suit an M4 Threaded Insert. This was the reason that the grain needed to be across the part rather than along its length - you should never screw into end-grain.

The last part I made a start on today was the ‘Key-hole’ Plates from 1.5mm Brass plate. I did think about making them on the Denford but decided that the Mill was a better option since they are just oblong flat parts with a ‘Key Hole’ and two countersunk holes for screws and the Mill is more robust and can take a 1.5mm cut with a 5mm end-mill in one pass whereas I would have to let the Denford take 8 - 0.2mm cuts.

*13th Nov*
Fig-116 will give you a better idea how each of the parts I’ve been working over the past few days fit together. They are all concerned with fixing the clock to a wall. The Wall Plate screws to the wall via the two holes with the Brass Screw Cups to provide two ‘hooks’ (via the ‘Key-hole Plates’) for the Mounting Buttons (not yet made) to lock into. The Wall Mounting Spacers will be glued into recesses in the back of the Rear Frame ‘B’ section and the Mounting Buttons screw into the M4 threaded inserts.

The Vertical Adjusting Screw, Spacer, Nut & Wall Pad go at the bottom 


of the Rear Frame ‘A’ Section so, along with the two Mounting Buttons, provide a three point fixing.

The first operation of the 8 Mounting Buttons is now done (left hand image of Fig-117) so tomorrow I should be able to turn them around and machine the M4 thread.

*14th Nov*
Well that didn’t go well, or rather I struggled with cutting the M4 threads - not with machining down to 4mm Ø but die-ing the thread. Had I been 


using En1a material rather than 304 Stainless I’m sure it would have been a breeze but only being able to hold on a 2mm long x 8mm Ø, the stresses involved in cutting even an M4 thread were ‘challenging’ and the part was slipping in the chuck. The fact that I wasn’t feeling 100% health-wise, the workshop was quite chilly and there was both F1 and ‘Strictly’ to watch during the day, meant that I gave up after two had taken me the best part of an hour.

The right hand image in Fig-117 is the finished ‘Button’ and Fig-118 shows it attached to the Wall Mounting Block.

*15th Nov*
Feeling somewhat better, I tried again this morning but wasn’t happy with the first M4 thread which I could only die about 5mm of the 8 but it did fit in the mating part so can be used. I should have understood from past experience that having only a small section to hold on to would cause problems - with Stainless Steel. Free-cutting En1a would not be such an issue. 

The upshot was that I bit the bullet and decided to re-make the Mounting Buttons and cut the M4 thread first. The first two off the lathe was relatively easy and the prospect of holding on the thread - even screwing it into a ‘nut’ - would make second op. machining of the Button face a doddle.

Machinery/components always want to assert their authority though and the third thread I cut made sure I knew who was in charge when I was a little too keen to make sure the thread was fully up to the shoulder — there really is no need for that to be the case since the threaded insert has a 3mm deep clearance — but the last 1/3 turn of the work sheared the thread off - naturally leaving the thread in the die  Drilling that out was going to be ‘fun’, so I anticipated all the potential problems and started with a 2.2mm Ø drill which did cut about 6mm deep before I turned the die over to work from the other side – that’s when the drill broke !! 

I finally did get the stainless steel out of the die by using a short 3.2mm Ø drill and a variety of pin punches to deform the remains of the thread. Can’t show you how or what the problem was because in my ire I simply got the thread out rather than taking photo’s of the mess. The next 5 all went without incident and I’ve now machined the front faces as well.

*16th Nov*
Today I returned to making gears - well more of the 72 tooth main drive gear - making small modifications to the G-Code in the light of further experience as well as taking account of the fact that I no longer have a 3mm TCT router bit. Knowing that the 2mm Ø Burr will easily stand up to a 1.5mm cut, I didn’t bother doing two roughing cuts for the tooth outline, I did one cut leaving 0.3mm to be removed by a 0.8mm Ø burr. Looking at the first one I made (a month ago!) I decided to increase the speed to 20k rpm (was 15k) and reduce the feed to 80mm/m (from 120). This meant that the final cut of the teeth took 45 minutes but I’m not concerned about time - there plenty of other work to do 




It’s suddenly occurred to me that you may not be familiar with the type of ‘Burrs’ or ‘Up-Cut’ end mills that I’m using so in Fig-119 I’ve put 4 of these alongside a 5 pence piece (18mm Ø) and a ruler marked in mm - essentially to give you a sense of scale. From Left to Right they are 2mm Burr, 0.8mm Burr, 1/8" up-cut End Mill and 1mm up-cut End Mill. They all have a 1/8" Ø shank.

You can see that the flutes on the 1mm End Mill are quite short - in fact it can only cut 6 - possibly 7mm - deep, that is why I’m using the 0.8mm Burr to finish off the gear teeth because the 72T Main Drive Gear is 8mm finished so needs to be cut 9mm deep. I would prefer to use End Mills because they are stronger and will do so for the smaller gears which have still to be cut.

Earlier today I said that I’d increased the speed to 20k from 15k but after finishing the first gear I noticed a little ‘burning’ on some of the teeth so I changed that again to 18k - I also fitted a brand new 0.8mm Burr since the one in use was showing signs of heating. I had occasion to go past the Denford after about 7 minutes into the run and noticed that the new burr had broken!! After fitting yet another, I reduced the depth of cut by 50% as well. That still didn’t stop the new burr breaking so I re-jigged the G-Code to use the 1mm End Mill for the first 7mm and finally the 0.8mm burr for the last 2mm but in 1mm increments.


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## donwatson (17 Nov 2020)

Thanks JG


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## J-G (20 Nov 2020)

*17th Nov*
I left the Denford working away last night and was disappointed to find yet another broken burr and an unfinished gear when I went in the workshop this morning. I can’t see why three new burrs from the same batch have succumbed to the smaller stresses - after I reduced feed, increased speed and halved depth of cut but it seems prudent to change tactics. To that end I’ve taken a day off to ponder the options.





It’s too late now to do anything with the gear in Fig-120 since I’ve taken it off the Denford table and the chance of re-mounting in the identical location within the 0.01mm tolerance that would be useful is impossible so I’ll have to finish the last 2mm of each tooth by hand.




I have mounted the next blank and run the G-Code as far as roughing out the teeth. Whilst that was running I looked at what cutters I had that would handle the 9mm depth. All the Burrs will, but the smallest I have (above the 0.8mm) is 1.8 and the small end mills won’t go deeper than 7mm.
Not to be defeated, I decided to modify a 1.5mm end mill by grinding away part of the shank such that it wouldn’t foul the top of the teeth - Fig-121 shows the result.

Tomorrow I’ll run the G-Code to finish the teeth with the 1mm end mill which can get down to 7mm and create new code to use the 1.5mm cutter for the last 2mm. Because the 1.5mm cutter won’t be able to get quite as close to the ideal tooth form, it will mean that I’ll still have to do some ‘fettling’ on the teeth once I’ve cleaned the face of the gear to 8mm thick - but I won’t have run out of the 0.8mm burrs!! 

*17th Nov*
Sleeping on a problem - I often find - has a beneficial effect and, after I’d set the G-Code running using the 1.5mm modified cutter, I had a look at what options my mind had brought to the fore overnight.

My concern was that the gear tooth form could not be followed closely with a 2mm Ø cutter – ie. that there would be potential for binding because the ‘root’ hadn’t been fully cleaned out – this was only from a ‘thought process’ rather than empirical study. So, - I’ve now done a drawing of the tooth form at a 10x enlargement and along that plotted the path of the centre-line of the cutters at 2.0, 1.5, 1.0 & 0.8mm Ø.



As you can see from the drawing which is Fig-122, I was surprised to find that my concerns were totally unfounded. Even a 2mm cutter will reach into the deepest recesses of the root so all my faffing about - read that as breaking tooling!! - over the past three days has been without benefit  Unless of course you consider that the learning curve has its own benefit!

I think that I’ll still use the 1.5mm cutter (especially since I’ve already increased its reach) because it is an ‘Up-Cut End Mill rather than a ‘Burr’ so should leave a cleaner finish. 

I’ve just checked and even a 3mm Ø cutter would still cut down to the root correctly but a 1/8" (3.175mm) would not, and I’ve only been able to source Up-Cut end mills at 1, 1.5 and 3.175mm Ø (at sensible prices anyway).

*18th Nov*
The last 72T Main Drive Gear did get completed using the modified 1.5mm end mill and all four were finished to 8mm thick on the lathe where I also finish bored out the centre hold to fit the p


ositioning Boss and the Ratchet clearance recess. All four are assembled (Fig-123) on their spindles along with the Ratchet and Winding Drum but without the Pawls or Pawl Pins - the Pins will be a press fit and I only want to do that operation once so it will be left until after I’ve applied the ‘finish’ which will be Sanding Sealer and MC Wax.

I also found time to cut the slot in the Lower Frame Spacer to accommodate the Frame Brace. 

Initially, I thought to cut the slot on the Milling machine but soon realized that it would be both quicker and more accurate to do it on the Denford - primarily due to the difficulty of getting the parts absolutely level in the Milling Vice. The Denford table is, by design, flat and 


level so setting up a clamp to accurately position the 16mm Ø spacers was a few moments work and the actual machining would only take 2 minutes at most — it just meant that I had to spend 30 minutes or so drawing the tool paths and creating the G-Code. I suspect that it would have taken an hour to do the job on the Mill with the prospect of error.

The M5 threaded inserts which will eventually be screwed into the Front Frame have all been fitted to the clamping spindles so that I know that I have sufficient and don’t need to order more stock. Fig-124 has one of the rear frames loose assembled with the Frame Brace, Spacer & Clamp spindle.

*19th Nov*
Back to CNC and Gears - When I made the 32T Gears I was still drilling and counter-boring holes in the basic stock to machine the surface down close to the finished thickness but I’ve learned from making the 72T gears that putting the part finished Gear on the lathe to skim to finished thickness is easier to do - both as far as holding and machining is concerned. For the 30T gears I made today I didn’t even cut the 400 x 64 x 10 Maple blank down to the 297mm length that I needed to cover the four so there was room to fit a 10T Pinion on as well – I needed another due to knocking a part assembled unit over and after a week of hunting still can’t find the Pinion that was in the assembly. Now I’ve made another I’m sure it will turn up!

Up to now I’ve left the ‘waste’ at the thickness of the blank and used a Jeweller’s saw to cut the components out, thinking that I might want to use the ‘waste’ for other projects but I now have boxes full of off-cuts of Maple and Walnut and am less of a scrooge  so when I prepared the drawing for these gears I planned in an area to be machined away so that the gears could be cut off and held in the lathe chuck. 







In Fig-125 you can see the gears with the waste removed and Fig-126 after they’ve been separated on the band-saw ready for finishing on the lathe.

Because the width of the blank was very close to the O/D of the gears, I had to be very precise with the positioning in the Y axis such that even adding strips of paper/thin card made a difference.


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## donwatson (21 Nov 2020)

Thanks JG


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## J-G (22 Nov 2020)

*20th Nov*
This is a day I will remember!!




I’d determined to give the Denford something to do while I set about finishing the 30T gears and rather than start on the Dial – for which I have the blanks semi-prepared – the 64T & 60T gears looked to be the best bet.

My work-flow now starts with determining what size the blank material is so naturally I needed to look at the Maple plank I have to make sure that I could cut three slices at 7+mm thick. I knew it had some ‘edge damage’ (see Fig-127) but imagine my dismay at realizing that when I cut a piece off the one side, to make the Frame Spacers, the board finished up at 130mm and to make the 64T Gears I need a clear 132mm !!

Clearly a re-think was needed so my ‘fall-back’ position turned out to be making up composite boards using the 64mm x 10mm thick Maple offcuts which I rebated along the 410mm length to make half-lap joints. As I was preparing a suitable clamping jig for the glue-up I had a phone call from my Grandson (who lives with me) enquiring if I was home. On hearing that I was, he suggested that I not venture out since he had just been tested Positive for COVID-19  

I knew I should have gone shopping yesterday but my ‘needed’ list was small. The rest of the day was taken up with finding out what I needed to do as far as getting a test was concerned and learning about the horrors of on-line-shopping!!

As I said - a day to remember!

*21st Nov*
Back to the Maple glue-up and the 64T gears. I finished the clamping jig and glued up the three lengths to give me a 160mm x 410mm board (Fig-128 is the jig with the Maple under pressure) from which I can cut three Gears. The Denford has a 400mm ‘soft’ limit on the X axis but by judicious testing this morning I’ve found that I can push it to +205 so I do have a little more leeway than I thought.




At 162mm the board is just a little too wide to allow me to clamp it on the table using the eccentric jaw so I’m going to return to clamping by screwing down. I don’t have to skim the surface so there is no need to sink the screws and the heads will be avoided by using a 6mm Ø cutter to cut outside the red line in Fig-129 to clear the area around each gear to ease the separation on the band-saw.






The space between the gears should be cleared by the smaller cutters when they are forming the teeth.

The brown bands in Fig-129 show the position of the half-laps.




That went pretty much to plan though I did stop the first clearance profile when it got to the bottom of the centre Gear because it was too low. A small adjustment to the position of the whole drawing in CamBam and a re-generation of the G-Code soon corrected that. 





I surmised that the clearance space between each gear would be removed by the 2mm cutter but you can see in Fig-131 that was not the case. Not that it matters


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## donwatson (22 Nov 2020)

I hope it goes well with your test. Stay Safe.
Thanks again for the WIP.


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## J-G (22 Nov 2020)

Thanks Don, since I don't have any symptoms (neither does Steven) I can't get a free test -- I'm sure that I could get a test at one of the 'walk in' centres I've been told about but that would mean breaking my isolation which sort of defeats the object.

Combine that with the fact that any test is like an MOT - it is only valid at time of issue - and there is no guarantee that, having been tested, one cannot pick up an infection on leaving the test centre - or at any time on the journey back to isolation.

Steven has been tested every week for the past month since he is working in a food distribution centre and the company are testing every member of staff regularly. Upon testing positive he was immediately escorted off the premises and bundled into a taxi !


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## J-G (26 Nov 2020)

*22nd Nov*
A busy and productive day which started with making another composite board as a blank for the last 64T and the first two 60T gears. Naturally, that had to be left on the clamps until the glue had cured so there was plenty of time to create the new drawing and G-Code. I soon realized that I’d forgotten to measure the width of the new board (the Maple off-cuts are not all the same width) so although I could place the outlines of the three gears roughly in position, I would have to wait until I could release it from the clamps before finalising the G-Code. Just as with the previous board, I’d decided to cut a 6mm wide clearance ‘slot’ but, knowing the mis-alignment issues I’d had, thought to create a ‘test cut’ only ½mm deep to make sure that I didn’t need to stop the run and re-align after a deeper cut.

As expected, cutting the three 64T Gears out on the band-saw was easy, and left me with a clear means to grip them in Beech Jaws - Fig-132 is a photo taken after I’d started to cut away the excess – ie. I nearly forgot! – You can see that with the blank at 10mm thick and the gear outline being 8mm deep there is a 2mm ‘slab’ that has to be removed 


just to get the waste between the spokes out. Ultimately the thickness has to be reduced to 5mm and because these gears are cut from a half-lapped composite board that has to be done from both sides.
In Fig-133 you can see the 64T Gear still in the Beech jaws at the finished 5mm thick. Similarly, Fig-134 is the 30T Gear held in a smaller recess in the jaws.








*26th Nov*
Although there has been a 4 day gap since my last comment, I’ve not been idle, it’s a combination of other commitments and the fact that nothing had gone wrong and worthy of reporting – or so I thought!

Much of the time has been spent on repeating many of the tasks already mentioned but also further work on the rough-sawn Dial Blanks. Since these blanks will need work on both sides, it is imperative that they can be positioned accurately when ‘flipped over’ so the first thing I had to do was make a positioning jig - nothing extraordinary just a piece of 10mm ply screwed to the table and machined in position to provide constant X and Y axis end stops. There are 20 blanks in total and cleaning the surface by taking 0.5mm skims off each side until such time that all the saw marks were removed simply took what seemed forever.

Once they were all clean and finished at 6mm thickness, the ends also needed to be machined square. I had determined that they needed to be 233mm long but due to a couple not cleaning up at that they finished at 230mm – no real problem I thought, a little ‘tight’ but judicious positioning of the outline should sort that out. To make absolutely sure of that I set about printing ‘life size’ images of the five Dial sections so that I could easily check how much ‘adjustment’ might be needed.




Drawing sections A & B didn’t cause me any concern but I was somewhat miffed when I looked at the overall length of section C and noticed that it was 242mm long...... again ‘Measure twice, cut once’ comes to mind but in this case that should be ‘check all components twice’! Section D & E do not present a problem but another ‘annoyance’ is that I could, with a little forethought, easily have made the blank for ‘E’ shorter and ‘C’ longer. I now have to start from scratch to make 4 blanks for section C.


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## donwatson (27 Nov 2020)

I think you are making an outstanding job of this and can only commend your perseverence and your knowledge of the subject. Thanks again for the info.


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## J-G (1 Dec 2020)

Thanks Don -- you're not the first to reference my perseverance  I seldom give up on any problem without a positive result as many of my computing customers will attest.

It's been a few days since I posted an update so it seems reasonable to confirm that it continues at 26th Nov.
==============================================================================

That was not as onerous as I thought - I still have Walnut in the original plank, the table saw is still set up (it often resides tucked under a bench-top since I don’t use it that often) and the Denford still has the Dial Blank Jig fitted.

I took the opportunity to re-surface all of the Dial blanks down to 5.5mm, leaving just 0.5mm excess over the finished size so I don’t have to mess about making the depth of the joints cut from opposite sides different, I’ll make them both 2.75mm. This will also help to make sure that when I cut the slots for the Hour Battens and holes for the Minute Dots I can afford to go 2.5mm deep to make sure that they won’t be trimmed out of existence when I do the final surface skim.

*27th Nov*
I decided that it would be good to have the Battens available before I start machining the Dial parts. I had initially thought to make the Battens on the Mill but sanity prevailed and I realized that it made much more sense to cut them on the Denford and once I started the drawing saw that making two together - end to end - would also be more efficient. Fig-136 is a drawing of the Dial Section A 


with Maple Hour Battens & Minute Dots to show the potential problems that I’m likely to encounter.

You’ll notice that the Batten on the right is very close to the joint. This particular joint is in fact at the 12 o’clock position which has two Battens - one each side of the joint line - with only 3mm between the battens at the closest point, so having the Batten in place before I cut the joint will afford some protection to the Walnut.

With this in mind I created a drawing of the Battens as in Fig-137 after preparing a small piece of Maple - 150mm x 48mm - and skimming the surface down to 3mm thick. This would be sufficient to make 24 Battens (in case there were ‘failures’) and I only need 16 . . . . . well that’s what I thought . . . . What I actually need is 16 for each Dial - so in reality I need 64!



When I created the G-Code, I set ‘holding tabs’ in the centre top and bottom of each Batten pair thinking that this would be sufficient to hold them all in place and would be where they would be separated. The reality was that cutting right through the 3mm caused some ‘chatter’ at the bottom right of the first column but that only lost one so I left the Denford to com


plete the second column. Coming back a while later I wasn’t pleased to see the mess in Fig-138. At least I didn’t come back to find a broken cutter! That was very welcome since it is a brand new 1.5mm Ø Up-Cut router bit with a flute length of 12mm which I found along with a 4mm x 22mm flute and a 2mm x 22mm flute at reasonably sensible prices. I will be able to rescue 16 Battens but of course I need to make another 48. For these I’ll reduce the depth to 2.8mm, that will be plenty to fill the 2.5mm deep slots I have designed into the G-Code for the Dial Sections though.

*That did not go well!!. . . . .* When I saw the first cut, I thought it was a little wide but let the process continue. It was a fortuitous that I kept a watching brief while doing other work because it was suddenly obvious that the X axis had stopped working again!! I was able to stop the run before too much damage was done but then noticed that my initial suspicion that the cut was wider than the 2mm that I expected from a 2mm End Mill was true. In fact the brand new 2mm cutter actually cut a 2.6mm wide swathe. This meant that the Battens were in fact not 4mm wide as designed and drawn, but just over 3mm. I can only surmise that the length of the cutter (22mm) means that at 15000rpm there is some ‘whip’ which is somewhat disconcerting but may only be a problem when the depth of cut is small - in this case it was 0.5mm.

I’ve now re-visited the CamBam file and modified it to specify my existing short 1.5mm end mill and am in the process of cutting the second batch. I can recover half of the first 24 Batten blank due to the way that CamBam 


organized the cutting order (Fig-139) but I’ll still need to prepare another thin Maple blank to make another batch.


*28th Nov



*
At last I have successfully cut a sheet of 28 - increased from 24 because with a 1.5mm cutter it was possible to get another row in - and another 14 from the first blank.

D’oh! - - - The astute among you will notice that when I dressed this morning I put my ‘Stupid’ head on  Though that might be true of yesterday as well! I’ve mentioned making batches of 24 and 28 Battens, but if you look at Fig-140 carefully you’ll see that there are 56 Battens so with the extra blanks I’ve made, and without counting my first two failed attempts, I’ve actually made 128 - and taking account of the fact that I’ve cleaned off the ‘Holding Tabs’ on the linisher by hand so there may well be some variance in the finished width I can at least select the best when I come to fit them into the Dial. I also sat and watched as my Fly-cutter ran into the clamps  I simply thought “it’ll change direction before it reaches those” - - - - Oh no it didn’t.

I can now prepare the G-Code for the Dial sections so I’m starting with ‘C’, which is at the bottom and has 4 Battens, 10 Minute Dots & two joints all cut from the front. The only thing it has on the back is a hole for the Dial Locating Peg.

Having been caught out by the new 2mm End Mill cutting at 2.6mm I thought it wise to do a test cut with the 4mm cutter which came from the same source. Slightly annoyed that I missed the part in the description that said 4mm shank - I had expected either 1/8" or 6mm - it is 4mm, and I don’t have a 4mm collet! One of the advantages of having a reasonably equipped workshop is that I can make tools, jigs and fixtures pretty much as and when needed, so 15 minutes on the lathe and mill and I now do have a holder for 4mm shank tools to fit a ½” collet. I’m sure that is running ‘true’ but the test cut showed that the 4mm End Mill cuts a slot 4.3mm wide - good job I checked!

This means a re-think as far as the G-Code is concerned so I’ll now use a 1/8" cutter and an inside profile MOP rather than an Engrave MOP - I now have to do a test to make sure the 1/8" cutter rings true.

*29th Nov*
I do hate it when ‘tests’ are inconclusive. A slot drawn at 4mm wide cut with my 1/8" (3.175mm) End Mill set at 3.175mm for a profile MOP finished up at 4.3mm wide but a drilled hole was 3.2mm Ø!! A hole drilled in the same way with the new 4mm End Mill was 4.6mm. The next test was a 4mm slot cut with the tool diameter set at 2.6mm which produced a slot just a smidgen over 4mm. Thinking outside the box I then mounted the 4mmØ Single Flute TCT cutter which I’ve had for some time and did a test drill with that - - - Spot on at 4mm! I didn’t bother with a test ‘slot’, I’m happy to go with the 3.175mm mill being called 2.6mm.




It now feels as though I’m moving forward again since I have the section C of all four Dials cut out and with Battens, Minute Dot holes and Joints all cut. Fig-141 shows the Maple Battens in place. These aren’t glued in yet but I will do that on the A & E sections before I cut the joints for the reasons I mentioned on the 27th.

I pressed on with Section D which needed a joint cut on the second side and this did cause me a small problem - it seems that every new component raises yet another ‘issue’ that I hadn’t considered - naturally, cutting right through a blank, even though I am putting in ‘Holding Tabs’ means that the blank is not as solid, so when I turned it over to cut the second joint the grip afforded by the clamping was no where near as high as it was for the solid blank when I cut the first joint. The first time I noticed that


this was an issue was at the first cut at 1.3mm deep and the blank just moved with the cutter in the X axis! I was able to abort the run and clamp both ends but I still reduced the cut to 0.4mm - it just took that much longer. By now I had glued the Battens in so I had to cut them back to level on the Linisher otherwise the depth of the second joint couldn’t have been controlled.

I did get all four Dial D sections completed before Strictly and F1 needed my attention though.

*30th Nov*
The second operation clamping issue made me re-think how I organized the order of operations for the next part - Section B - and I realized that there was no reason that I couldn’t cut the second joint before cutting the outline, so that is how I organized the G-Code for this and all subsequent sections.

That modification to the cutting order was a definite benefit and I now have four of the five sections complete - well as far as the machining operations are concerned, I still have to break them out of the blanks and clean up the joints but hopefully tomorrow will see the Dial ready for glue-up or at least I should be in a position to set up a glue-up jig.

*1st Dec*
An auspicious day since I entered this world 79 years ago - how time has flown and what changes I’ve seen – or not ?? in 1941 death was all around but so it is today - very different reasons but the bottom line is the same.

I have now finished the last section of the Dial but the manual clean up and final fitting of all the joints - just niggling small (less than ½mm) adjustments to the length of the half-laps so that they ‘nestle’ into each other - on only one Dial has taken me most of the afternoon. Fig-143 is the first Dial simply laid out without glue. It was very satisfying to measure the width and height at within a millimetre of the designed 340mm, by the time it is glued up I anticipate that it will be spot on.


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## J-G (4 Dec 2020)

*2nd Dec




*As I hoped, I set up a jig to position and clamp down the 5 sections of each dial while the glue cures. It was heartening to see that the glue just squeezed out of the joints when I gently tapped up the wedges going around them 3 or 4 times. The image at Fig-144 is the first one and releasing that was a little stressful because some glue had seeped out of the back of each joint so I had to apply a gentle tap on a chisel to release it. For the second Dial I added a piece of paper under each joint! 

The first Dial has now had the Minute Dots added not as tedious as I had been thinking. Normally I get bored when I have to make more than 4 of the same part and this needed 48 but in fact turning a short length of Maple down from 6mm square to 4mm Ø and cutting of 3mm long lengths went remarkably well. As you can see in Fig-145 the curved joint at the 5 o’clock position is ‘tight’ (as are the others) and the Dots are glued in and stand just a little proud. They will be sanded back flat and level with the Walnut on the Mill using a 50mm Ø sanding pad and then finished with the Makita ROS.




I’m not sure that there is any benefit in leaving the Denford to get on with running a G-Code file while I get on with other work.

This has been my methodology for some time and I’ve been caught out by something going wrong and destroying the CNC work because I wasn’t watching its every move and hitting the emergency [STOP] as soon as any error occurred.

This was brought home today when the blank for the two Escape Wheels released itself from the clamps allowing movement in the X axis. I was totally unaware that there was anything amiss until after the run was complete and I returned with the intention of changing the tool and setting up the next operation. The first thing I noticed was that the 2mm burr was broken and then I saw the mess that had been made - Fig-146 - I suspect that the Burr had broken because it was being forced to take a deep cut due to the movement of the blank which I suspect was caused by it getting hot and warping because of 


the moisture content. When I took it off the Denford I could see that it had ‘curled up’ about 3mm - and when you consider that it is only 8mm thick that is a serious amount and certainly enough to release it from the clamp. Basically, this is down to my reliance upon the eccentric clamp rather than drilling clamping holes and screwing the blank down.

*4th Dec*
To make the blank for the last two Escape Wheels I used up the last stock of my 10mm thick Maple offcuts but fortunately I do still have the Hard Maple board and it is 130mm wide so sufficient to cover the 120mm Ø needed. The only ‘issue’ being that the board is 27mm thick so I had to cut a 10mm thick slice (or rather two slices) off and skim them down to 8mm before running the G-Code again.

Strangely, I didn’t learn from my previous mistake  and still didn’t screw the blank down, nor even clamp the corners, so would you believe that I had a similar failure! - again, for exactly the same reason 

A third slice off the Maple board and this time I did clamp them down at each corner and eventually got the last two Escape Wheels completed - well, as far as CNC machining is concerned - I still have to mount them on the lathe to trim the faces to finished thickness so there is still an opportunity to scrap them 

At least I did finish the Dial Minute Dots as my multi-tasking operation, so the four Dials are ready for finish sanding


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## donwatson (6 Dec 2020)

Thanks again JG


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## J-G (9 Dec 2020)

*5th Dec*
With the last two Escape Wheels completed I think that all the CNC work is now done so I need a time of ‘reflection’ and checking all the components do fit together. I still have some lathe work to do on the 64T gears, Escape Wheels & Minute/Hour Train since they aren’t yet mounted on their spindles.

*6th Dec*
I discovered today that not only had I not made the short spindle for the Minute/Hour train, I hadn’t even done the engineering drawing for it! That wasn’t such an issue really because it’s a very small part and it took only 10 minutes to sort out. Fitting the Spindles to the Escape Wheel and 64T Gears proved interesting. The spacers had been made 3 or 4 weeks ago so naturally there had been some movement in the timber and I had to Ream the bores out again and drill & tap the M3 holes which clamp the Gear assemblies to the Spindles. It’s amazing how long it takes to fit components like this together but at the end of the day I did at least have the gears mounted on all the spindles.

*7**th Dec


*
The first thing I did this morning was to see whether the gears on the three main spindles would mesh together. The rear frame was already fitted together but not glued and I haven’t yet fixed the pinions absolutely to the gears because I want to be able to finish sand the surface and apply sanding sealer/MC Wax before final assembly but there is sufficient ‘interference fit’ to see whether rotating the Escape Wheel causes the whole train to rotate.

It was encouraging to find that I could ‘spin’ the Escape Wheel and the whole train moved. The problem manifested itself when I then fitted the front frame which forced the spindles to be parallel which proved that there is insufficient clearance between the Gear and Pinion mesh. I could rotate the Escape Wheel about a quarter turn which means that the error is not great but still unacceptable. To some extent this was to be expected because I tend to work (draw) to an ‘ideal’ size.

There are a number of ways to effect a solution;

1 - re-cut the location of the bearing seats in the frame - 1mm each would be ample.

2 - Make an abrasive stick and ‘file’ each tooth - or make a jig to do the same thing on the mill using a burr.

3 - re-make the pinions using an effective diameter 1mm smaller.

The first option may well affect the mesh between the main Driving Wheel and the 32T Gear on the centre spindle which would complicate matters further.

Nº 2 would be tedious and liable to make each tooth different.




The third seems to be the best option and would also give me a chance to correct the small ‘irritations’ in the way that the CNC process cut the ‘hubs’ which fit in the gears. Fig-148 shows the hub damage due to the method I used to cut them. The Pinion on the right is how they should be but the one on the left shows that the thin wall has broken away - this is due to cutting a circle with an end-mill and proves that it is important to use CNC where the benefits are to be 


had but not just because it is possible to do the job that way.

With hindsight, I would now just CNC the pinion leaves (teeth) and then turn and bore the hubs on the lathe holding the Pinion in a four jaw chuck.

The blue line in Fig-149 is the original outline/profile of the 8T Pinion and the Red line is the re-worked profile. A two minute job in CorelDRAW!

I’ve created the new DFX & G-Code files to make 8 Pinions and found out why there is a ‘bind’ - I’d created the G-Code for the gear outline ’finishing cut’ specifying a 1.5mm cutter but the cutter I fitted is 1mm Ø !!

*8th Dec*
Making the 8 Pinions went pretty much without a hitch but I then considered how I was going to hold them in the lathe to both remove the excess material from the back but also turn the hub & bore.

I’ve mentioned previously that I have what I’ve termed ‘Beech Jaws’ to hold


the larger gears. These are simply blocks of Beech which I’d previously made to fit on the three jaw engineering chucks that I have. They are fixed to ‘Soft’ jaws which I’ve drilled & tapped. For Fig-150 I’ve removed one of the Beech Jaws so that you can see exactly how this works.

I can prepare the jaws to hold any component truly concentric by first clamping a small piece of steel in the metal jaws and then bore the Beech close to the diameter of the new part that I need to hold. I can also simply glue a new block of wood to the Beech - the triangular blocks are in fact Maple that came out of the gears - and just re-cut them as often as necessary.

This methodology is very good but has a limitation due to being only 3 jaw which is generally no problem when needing to hold objects which are already ‘round’ but not when you start with a square. An 8 tooth gear/pinion is effectively a square component so could not be held easily - even if I were to glue new blocks to make the grip smaller.

I do also have a 4 jaw self-centering chuck with ‘carriers’ - for which I also have a number of jaws but they are all ‘hard’ so can’t be machined for absolute concentricity. Notwithstanding that limitation, having made Beech Jaws for the 3 Jaw chuck I saw no reason that I couldn’t do the same for the 4 Jaw. The small irritation that had stopped me doing this previously was the fact that the carriers on the 4 jaw have a circular location ridge which would be difficult if not impossible to cut on the mill without de-mounting the vice and fitting a dividing head but now I have a CNC machine those constraints vanish.



It still took me all morning to design, draw, G-Code and make 4 Ash jaws but the result will be a massive benefit to future projects. I drilled & counter-bored holes for both screw holes in each jaw but the next time I make them I’ll 


only use the outermost one. This will allow me to hold much smaller objects. . . . . . I could remove the innermost screws and glue a new block in place of course but I have already finished the 8T Pinions and fitted them to the spindles. The jaws - along with the Pinion blank and finished Pinion are in Fig-151 & 2.


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## AES (17 Dec 2020)

Well, this CONTINUES to be what I would describe as being a superb WIP J-G. Again thanks for all your effort.

It's been a while since I've been here 'cos I'm myself working on a lengthy WIP about a child's pedal car toy. It's turning out MUCH longer than I expected (I'm up to Part Ten and reckon there will be about 15 Parts when finished) with lots of words and lots of photos + a few hand-drawn diags.

If you remember a comment I made earlier (Oct/Nov time), I've definitely given up using MS Word (except for initial drafts from "blank paper" which then get "polished" on the actual Forum page). That takes time - and BTW, you were dead right, whatever it is that MS Word does to embedded pix (I'm using .jpg format) the UKW Forum software does NOT like it! So it's loading photos direct on to the Forum from my PC hard drive (I don't do photo hosting).

All of which has nothing to do with your EXCELLENT WIP. It's too late for me and this toy car, but next time ("Next time????? I haven't even finished the current one yet!!!") I shall definitely try the idea of your "planning/diary" approach - that would have saved me from a couple of problems with my "mods with un-for-seen consequences"!!!

BTW, I might have missed it, but I saw somewhere above that someone in your family had tested Covid positive but didn't see anything else. I do hope you and all yours are OK.

Thanks again and if it doesn't sound too patronising" keep up the good work.


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## J-G (17 Dec 2020)

AES said:


> Well, this CONTINUES to be what I would describe as being a superb WIP J-G. Again thanks for all your effort.


You're too kind AES.



AES said:


> It's been a while since I've been here 'cos I'm myself working on a lengthy WIP about a child's pedal car toy. It's turning out MUCH longer than I expected (I'm up to Part Ten and reckon there will be about 15 Parts when finished) with lots of words and lots of photos + a few hand-drawn diags.


These things always take longer than expected 



AES said:


> If you remember a comment I made earlier (Oct/Nov time), I've definitely given up using MS Word (except for initial drafts from "blank paper" which then get "polished" on the actual Forum page). That takes time - and BTW, you were dead right, whatever it is that MS Word does to embedded pix (I'm using .jpg format) the UKW Forum software does NOT like it! So it's loading photos direct on to the Forum from my PC hard drive (I don't do photo hosting).


MS Word converts any imported image to its own format - typical MS "I'm in charge" attitude. 
I avoid .JPG like the plague - every time you re-save a .JPG image you lose some detail and create 'artifacts'. Much better to convert to .PNG - even if your camera/phone initially exports a .JPG file.



AES said:


> All of which has nothing to do with your EXCELLENT WIP. It's too late for me and this toy car, but next time ("Next time????? I haven't even finished the current one yet!!!") I shall definitely try the idea of your "planning/diary" approach - that would have saved me from a couple of problems with my "mods with un-for-seen consequences"!!!


I haven't updated my WIP recently because I've been correcting some errors I made early on and it's taken me far too long. I have also been considering whether it is still beneficial since there has been very little feedback so your kind words have 'turned' that.



AES said:


> BTW, I might have missed it, but I saw somewhere above that someone in your family had tested Covid positive but didn't see anything else. I do hope you and all yours are OK.


Yes - my grandson (who lives with me) but neither of us have had any symptoms and have completed our self isolation.



AES said:


> Thanks again and if it doesn't sound too patronising" keep up the good work.


Your post has had a positive effect so look forward to an update shortly


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## AES (18 Dec 2020)

Thanks J-G.

If I may, a Q please. Using my old (V5) version of Photoshop Elements, I've just tried to save an originasl (straight off the camera) .jpg photo as .png, as you suggest above. When doing so a small options box appears asking me if I want "interlaced" or "not interlaced". Which should I choose please? I've just looked in my O'Reilly book about PS E V5 and can't find the answer. Can you advise/explain please?


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## J-G (18 Dec 2020)

Spurred on by AES I have spent the morning trying to recall my activities over the past week  I see that my last .PDF has not been viewed so that may indicate that Don is not currently able to read the forum, I do hope that does not mean that he is unwell.

An overlapping post from AES has just come in --- The point about 'interlaced' is to do with how quickly an image is displayed when being viewed on the internet. An interlaced image will show every other line of pixels - top to bottom - before returning to the top and 'filling in' the missing lines. On modern PCs and fast internet there is little difference and I often forget to select 'Interlaced' when the image is intended for the internet rather than local display but in general I would select interlaced for any web content.

===========================================================================
*9th Dec*
Having made eight new 8T Pinions and fitting them to the spindles that were to hand I realized that there were another four 8T Pinions needed as well as four 10T Pinions. These are for the gears which were not in the workshop simply because I needed more space and I’d forgotten them.

This meant that I had to create another drawing, DXF file and G-Code but having done multiple Pinions before I found that I changed the way that I handled the G-Code. Previously I had cut away a circle around the outside of each Pinion and then used a drill MOP to take away the main bulk of the space between the teeth only later using the outline to first do a rough cut and then a finishing cut. This time I used only the outline to first cut a swathe with a 4mm end mill leaving the teeth 1.3mm oversize followed by a 2mm burr leaving 0.4mm and finished with a 1mm end mill. The first two went 7mm deep and the last one 6


mm. The Pinion leaves need to finish at 5mm thick so there would be ample ‘meat’ to trim both faces on the lathe in the event that the top face sustained some damage - which I don’t think it has.

This method I think is much more efficient and ultimately produced a block (Fig-153) which will be simple to separate on the small bandsaw.

*10th Dec*
That still took some time and I needed to be cautious when trimming the excess from individual Pinions! Removing the inner screws from the Ash jaws and boring them out to glue on Maple pads was definitely worth while and made gripping these Pinions for the second operation much better.

The new - slimmer leaved and smaller - Pinions are definitely better but to be absolutely sure that they will run freely I need to glue up the frames so that I can fix the locations of the bearings. The jig (read - flat board with screw blocks!) that I used to glue up the Dials was easily re-worked to apply pressure to each joint but it’s a one at a time


job so will take a day or two to complete the 8 frames.

*11th Dec*
When I spoke about gluing up the Dials, I mentioned that I would use a 50mm Ø sanding disk but forgot to take a photo – Fig-154 shows the same process but used on the frame. The pad is held in the collet on the mill and the height adjusted to suit the distance between the flat board (40mm Formica faced kitchen worktop offcut) held in a vice. I started with 60grit and will eventually get down to 320g.



*17th Dec*
The past few days have been spent correcting some errors I made due a naïve belief that it would be wise to cut all the recesses for the Bearings etc. at the same time that the frame sections were made. It certainly seemed sensible at the time but once the frames were glued together it became obvious that the exact location of the bearing positions needed to be determined relative to the main spindle (which carries the hands) and with the knowledge of the mesh of the Pinions & Gears. Even a difference of 0.1mm in the position of adjacent spindles can make a difference to a clock running for 5 minutes or 24 hours.

I was very pleased with the way that the frames went together as far as the joints mating was concerned but the position of the winding spindle holes caused some concern. This was primarily to do with the short Section D joint being an ‘easy’ fit. Add to this the issue that necessitated the re-cutting of the Pinions and I decided that it would be prudent to simply bite the bullet and re-cut all the bearing recesses, along with the positions of the frame spacers.

A great deal of head scratching was needed and some experimentation which ultimately detracted from the process of photo recording - ie. not being clear in my own mind what I wanted to do I resorted to my ‘norm’ of just getting on with the job in hand. So, I’ll add some drawings to show how I solved the various problems that arose.

Because the Gear/Pinion mesh would benefit from ‘a little extra’ separation, (which I had determined by trialing the fit of the hour/minute planetary gear pair) I decided that the most efficient way to reposition the bearings would be to machine a recess and insert a new piece of wood into which I could cut a new bearing recess. This would allow me to add 0.2mm to the centre distance. Greater than this and I would be in danger of compromising the escapement. The position of the hour/minute planetary gear doesn’t matter quite so much so I made that 1mm greater than originally designed.

The Denford has a maximum capacity of 400mm in the X Axis and 200mm in the Y Axis so cannot totally accommodate the assembled frame without some judicious positioning. Fig-155 shows how I positioned the frame to cut recesses for the new bearing inserts. I chose to use Maple and make this correction a ‘feature’ 

The black blocks are positioning aids which were machined with reference to the table centre locating peg (Red Cross). The Frame was kept in position by fitting three clamps.




Using this set-up I could machine the three Bearings along with the Hour/Min Axle and M5 Thread Insert 3. To cut the other Thread Insert recesses I had to re-position the frame as in Fig-156 which took a little more ingenuity as far as accurate positioning is concerned. By now the Bearing recesses had been machined and I knew exactly where 


Bearing 3 had to be so could create another G-Code file to cut a matching location hole in an overhanging Jig Block. At the time of writing this I had already taken a photo of a similar Jig Block so although out of sequence, Fig-157 will give you a better idea how this ‘overhang’ Jig Block allowed me to use a locating ‘Peg’.

D’oh! - preparing this photo I discovered that I _*had*_ taken a photo of the first positioning Jig Blocks - but for a different purpose - so that will be Fig-155A.







​My original intention was to screw the M5 Threaded inserts directly into the frame but once I’d decided to use inserted blocks to reposition the Bearings, it became obvious that doing the same with the Inserts made more sense. It is important that Threaded Inserts are screwed into ‘face’ rather than ‘end’ grain and turning small blocks of face grain timber on a lathe has its own limitations so after making a prototype by hand, I created a G-Code file to make 12 from an off-cut of Walnut. I didn’t bother with cutting the outside circle, just machined 12 holes with matching recesses and part cut separating slots. This allowed me to screw the threaded inserts in on the mill so that I could then mount them on the lathe to machine to finished size which would guarantee that the insert was correctly centred when glued into the frame. Fig-158 is a montage of two photo’s taken from top and bottom of the mounted insert after part machining.




Writing this ‘after the fact’ has meant that I’ve missed out some salient details as well as not taking photo’s!. Specifically I haven’t mentioned how I made the Maple inserts which had to be glued in place and sanded down to a level surface before machining the final recesses for the bearings. 

This was a simple matter of taking a 22mm wide strip of 8mm thick Maple and writing a G-Code file to cut 4 x 20mm Ø and 8 x 12mm Ø ‘buttons’. They were cut 7mm deep and then separated on the small bandsaw. Once the ‘buttons’ were glued in place the frames were returned to the Mill to have the excess sanded off before going back on the Denford to have the real Bearing recesses machined. This was also necessary for the Thread Insert repair blocks of course though they didn’t need a second operation.





Having spent all morning trying to remember what I’ve actually done over the past week, I think I am nearly up to date so can at least add a photo of the current state of the front Frame (Fig-159) showing all the corrections.

I now have to do the same with the Rear Frame which will entail solving all the same problems again but in the opposite hand! Hopefully it won’t take as long!

Before posting this update I’ll add a photo of the Front Frame but with the spacing rods and some of the gears/pinions in place.


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## AES (18 Dec 2020)

Thanks a lot for the info re .png J-G. Noted n understood.

Re the .pdfs, if donwatson is the same as me, I reckon what we're both doing is "speed reading" your on line stuff (i.e. mainly looking at the pics & glancing at the text n dates) then downloading your .pdf s for later perusal. I presently have I think 3 or 4 of your .pdf s that I haven't even opened yet (getting near to Xmas, the number of "honey do's" seems to grow exponentially - a bit like Covid really!

(If I can make that "joke" at this time without offending anyone - NO offence intended - e.g. here our "R number" is above 1.0 and still increasing and a lot of our hospitals are apparently really close to their staff limits, while out National and Kantonal governments argue with each other about what to do - pure political posturing IMO - so I'm really NOT making the above "joke" lightly).


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## Yojevol (18 Dec 2020)

Having now got my own Denford I'm taking a bit more interest in the machining aspect of this project. Up till now I've been more interested in the clock itself, so it's nice to see it coming together. 
Brian


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## donwatson (19 Dec 2020)

Thanks for posts JG. I had minor irritations and am now back. AES has hit it on the head when he describes what he does, that is my way also.
Originally I was interested in the clock itself with a side interest in the CNC machining but I have become totally absorbed in this WIP and have revived my interest in using my Stepcraft machine to maybe try another project.
Thanks again for this WIP it has been great working through you problems.
take care and stay safe
Don W


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## AES (19 Dec 2020)

Yeah, I've just "discovered" that I've got your WIP nos 28 to 31 on my hard drive and not even opened yet. It appears from looking at your actual pages, the downloads don't count as "read" on the note-thingy against each .pdf, so don't be disheartened Mate. "People" (well at least Don & me anyway!) ARE reading - AND enjoying.

Seasons greetings, and stay safe & well.


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## J-G (19 Dec 2020)

donwatson said:


> I had minor irritations and am now back.


Glad to hear that they were 'minor'  and to see you back of course.


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## J-G (19 Dec 2020)

AES said:


> ...so don't be disheartened Mate. "People" (well at least Don & me anyway!) ARE reading - AND enjoying.


Not really 'disheartened' but it would be encouraging to see [Views] changing - which was possible up to 1K but beyond that the forum just reports 2K, 3K etc. and it takes some time to record 1000 views 

To some extent it's a matter of knowing that what one does is useful to someone else which is why I record all the mistakes! No matter how forward thinking you may be there always seems to be an opportunity for 'life' to trip you up.

The .PDF views are noted separately from the thread views so I can tell if the .PDF has been downloaded which is why I had concerns over Don's welfare.


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## paulrbarnard (19 Dec 2020)

J-G said:


> Not really 'disheartened' but it would be encouraging to see [Views] changing - which was possible up to 1K but beyond that the forum just reports 2K, 3K etc. and it takes some time to record 1000 views
> 
> To some extent it's a matter of knowing that what one does is useful to someone else which is why I record all the mistakes! No matter how forward thinking you may be there always seems to be an opportunity for 'life' to trip you up.
> 
> The .PDF views are noted separately from the thread views so I can tell if the .PDF has been downloaded which is why I had concerns over Don's welfare.


I'm certainly enjoying it! Just commenting as I don't want you to stop posting before you have finished.


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## J-G (19 Dec 2020)

Thanks Paul - that's good to know.


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## Jester129 (19 Dec 2020)

So engrossed in the write-up that I (and I'm guessing umpteen others) fail to make a comment.
Don't be disheartened, I'm sure there are loads of us watching, but just staying silent. I certainly don't have the skill required to do what you're doing.


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## J-G (19 Dec 2020)

That's great Jester - not that you fail to make comment, but that you are engrossed. It hopefully means that my writing style is 'interesting'  Without feedback I often feel self-indulgent instead of potentially passing on knowledge.

I'm sure you could have the skill required, it's just that your interests lie in a different sphere so you haven't needed to acquire some of the skills that I have devoted my time to researching.


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## donwatson (20 Dec 2020)

Yes, very minor, the biggest one was life getting in the way of everything. I was 81 on the 9th and it coincided with a very good update from you. At my age a birthDAY usually turns into a week (and I am thankfull for it).
As I mentioned before, I had constructed a clock from 6mm plywood and brass rod and all cut on the Stepcraft CNC milling/router machine. I had no success with that and was wondering if I should try again. Your article has inspired me to do just that but when is another matter. In spite of all the frustrations I think I treat all these projects as FUN things and all part of the learning process, YES, even at my age your thirst for knowledge does not diminish. I am off now for elevenses.
take care and stay safe
Don W


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## J-G (22 Dec 2020)

Good to have that confirmation Don. In these 'weird' times one cannot make assumptions that all is well.​==============================================================================
*19th Dec*
Yesterday was taken up mostly with bringing the WIP up-to-date but I also spent some time making a pair of 20T Gears for a Startrite Mercury 2 drill which is being restored and the owner was having problems finding replacements at a sensible price. I did get the drawing of the Rear Frame converted to a .DXF file though.

Due to other pressing issues (Strictly Final  ) I only got 3 of the four Rear Frames machined today and even then made an error on the first because I forgot to change the Profile MOP from the default [Outside] to [inside] ! - I let the Denford finish the first recess which made it 14mm Ø instead of 12mm Ø. Since I hadn’t actually cut the Maple inserts it made little difference - I just had to remember to make one of the Maple buttons larger.

*20th Dec*
The fourth Rear Frame was machined ready for plugging with Maple buttons this morning and I remembered to take photo’s so you can get a better understanding of how I use the Screw Hole Grid on the Denford table to make location jigs along with clamps. Although the Eccentric Clamping Jaw in Fig-161 has fixing holes at 40mm centre (which fits the grid) in this case I needed it to be at 20° so one screw went into a grid hole but for the second I used a woodscrew into the ply sacrificial table.




Because I needed to re-position the frames once the Maple Insert Buttons had been glued in so as to cut the Bearing recesses I did not want to disturb the side locating block but at this time I hadn’t made the Maple Buttons. These buttons are 12, (14) & 18mm Ø and 6mm thick so can come out of offcuts.

In Fig-162 you can see the 12 buttons I need which have been machined using an ‘up-cutting’ end mill. The benefit of ‘up-cutting’ is that it lifts the waste 


material out which would otherwise be pushed into the narrow grooves potentially jamming the cutter but as you can see, the downside is that it leaves some tear-out. This is no big deal really as they will be glued into the Frame and sanded off flush before I cut the Bearing Recess. To make it easy to glue them into the Walnut I do need to ‘ease’ this torn-out edge because the recess and the button are cut to the same size. Up to now I’ve done this by hand with a 2nd Cut file, however, I suddenly had a ‘light-bulb’ moment and realized that it would be a simple matter to use an engraving cutter - which has a 20° relief angle (Fig-163) - to simply trim the edge, putting a small chamfer on it which would provide an easy squeeze under the bench press. Taking photo’s inside 


the Denford is not the easiest job so I’ve drawn a cross-section below the photo’ to make what I’m talking about as clear as possible.

To also make it very clear how these Maple buttons fit into the frame, in Fig-164 you can see the top two ready to be trimmed down before going back on the Denford to



have the Bearing recesses cut.

Once the Bearing recesses had been cut it only remained for me to prepare a new jig to hold the Frame perpendicular to the table so that I could cut the last two recesses for the Frame Spacers and I completed those late in the evening so tomorrow I hope to be in a position to build the basic frame.

Since I didn’t photograph the Front Frame in position for


machining the top threaded inserts - resorting to a drawing - Fig-165 is a photo’ of the rear frame in the similar orientation to have the Spacer Recesses cut. They are ostensibly in the same relative location since they are at opposite ends of the Frame Clamping screws.

The first attempt at assembling a frame mostly went as expected and I was pleased to see that the holes for the main centre spindle aligned spot on but I then noticed that I’d forgotten to drill & tap the holes for the ‘beat’ adjustment so that will be a challenge to overcome shortly - certainly before I do any glue-up of the spacers or the Frame Brace. The tentative assembly has revealed that the attention to detail as far as using jigs has paid off since I was easily able to slide the front frame down the spacer screws bringing both frames face-to-face. I will however need to do some ‘fine adjustment’ to things like the Frame Brace, Bottom Frame Spacer and Vertical Adjuster block – this is not unexpected since although I’m using CNC for much of the manufacture, some parts have to be done on the Mi


ll or Lathe so are subject to my personal reading of machine dials.

The part assembly does not have a ‘natural’ base which would enable it to stand alone so I had to take it a little further and fit the components which will ultimately fix it to the wall.

There is a Wall Plate with ‘Key-hole’ slots - see Fig-116 in WIP-24 - and I was again thankful to find that the two Mounting Buttons (Fig 117/8) dropped easily into the key-hole plates with no further adjustment so I could quickly screw the Wall Plate to a door and hang the part assembly to take a photo’.

I have to hope that the Dial Mounting Pads will align as easily!




Well that is very fortunate! My concerns over drilling and tapping the beat adjusting holes was unfounded.

It was a simple matter of using a slightly extended holder for a 2.5mm Ø drill in the mill and my standard T-wrench tap holder just cleared the top of the frame while still getting the tap through the one side. The two holes do not need to be absolutely aligned as there will be two separate grub screws acting on each side of a brass plate.

Before I can start a real assembly (glue-up) I will have to spend quite some time in sanding all the components to 320 grit, apply sanding sealer and MC Wax. The frames have been sanded to 120g but the rest are pretty much all straight off the tool.

[EDIT] - I realized that I'd forgotten to attach the .PDF  so I've taken the opportunity to add another Photo'

*22nd DEC*
I didn’t expect to get much done today due to other work that was temporal but I did find the time to do an assembly of the parts that - although not properly finished - are at least pretty much to size. That does not include the Dial because I haven’t yet made the Dial Pads. 

I will have to do some fine fettling of some of the Gear teeth to ensure that there are no ‘bindings’ at some parts of each rotation but overall the first mock assembly proves that they are free to run for at least 95% and all the spindles do fit into the bearings when the frames are clamped together with the spacers!



=================================================================================

Although I'm not going anywhere for the 'celebrations' I doubt that I'll get another posting done 'til they are over so I'll just wish everyone a Merry Christmas & a hope for a new year which is better than 2020 has been!


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## donwatson (23 Dec 2020)

Thanks again JG and a Merry Christmas to you and yours. Have a safe and healthy New Year.
Don W


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## J-G (23 Dec 2020)

Thanks Don - I've just done a small edit and added the .PDF file which I'd forgotten


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## AES (23 Dec 2020)

Thanks J-G. Your .pdf downloaded (but NOT read yet)!

If I haven't already said it - I forget, a lot on right now - best wishes of the season to you and yours, and stay healthy. All the best for 2021 (by which time I WILL have read/digested all your o/s .pdf's)!


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## J-G (29 Dec 2020)

In these strange times of isolation - or at least social distancing - 'holidays' and 'celebrations' don't have the same demands on ones time so working at a hobby does at least fill the day!

*24th Dec*
Having done all that I could to prepare for the festivities I found time to look at how I was going to make the hands. These are to be only 1mm thick for the majority of their length but the ‘hubs’ need to be 2mm so since they also have to be 200mm long and 20mm wide they present a number of problems. Mostly as regards holding the material.

For some reason beyond my ken, I thought to use the same methodology that I’d been using for the other components even though I knew that I would be using thin sheets of Walnut 60mm wide, 3mm (ish) thick and 430mm long. Actually the 3mm thick was after I’d removed the thicker centre part of the material I’d selected which was a remnant left after cutting other bits from the large Walnut plank. I forgot to take a photo’ so Fig- 169 is a drawing of the cross section which came about because I first ripped the board on the table saw and finished the separation on the bandsaw. (I hate waste  ) 




All went well as far as skimming the surface was concerned and I was selective in the order in which I did the CNC machining, first taking out the main lengths of the hands to 1mm below the hubs, then cutting the axle holes before moving on to the outline which I knew might cause a problem even though I’d built in nearly 50 ‘holding tabs’.

The biggest problem came when I pushed my luck and decided that cutting the outline another ½mm deeper to make sure that it was cut though was wise - it wasn’t !! - At this point I hadn’t done some operations and was disappointed to find (after returning to the workshop - multi-tasking again!) that the blank had disintegrated.




I did recover two of the four - and fortunately one Hour Hand and one Minute Hand so I do have a pair. They needed quite a bit of ‘fettling’ and I had to resort to my Jewellers Piercing saw to cut the ‘spring’ slots but ultimately I did get them fitted to the first assembly in time to show the current state of the Clock to those who are intended as the recipients during a Family Zoom meeting tomorrow.

*25th Dec*
I hadn’t intended to be in the workshop today but since I had done all the festive food preparation last evening and the fact that I don’t have youngsters demanding attention, there wasn’t a lot to do before actually starting cooking so I found myself reviewing the options, and indeed ‘getting my hands dirty’!

I already had a second ‘sheet’ of Walnut prepared because I needed another two pair of hands but using the same method of holding was obviously not going to produce a better result.

Why I hadn’t previously thought about using double-sided adhesive tape I don’t know but it suddenly made the most sense. I needed to prepare a sub-base using the surfacing fly-cutter and make sure that the Walnut had a clean flat surface which just meant a quick rub on the linisher. In Fig-171 you can see the double-sided tape on the walnut and the prepared sub-base in the background. Fig-172 has the Walnut affixed ready for machining.















I didn’t need to modify any of the G-Code so by just changing the cutter and adjusting the ‘Z’ height, I could cut the second set of hands.

This time I did get the spring slots cut with a 0.8mm Ø burr before cutting the outline, it was only when I came to do the finish outline cut that I had a problem. Since I didn’t use a full coverage of double sided tape - ostensibly because that would make the removal of the finished hands, without damaging them, more difficult (but primarily because I’m a cheapskate and DS Tape is relatively expensive - and can’t be reused!). The end result is that one of the Minute hands had lifted away from the sub-base and the stresses of the final cut - albeit only 0.3mm wide - was greater than the 1mm thick Walnut could stand so it broke away at the junction of the stem and the pentagon counter-weight. (Fig-173)

This means I still need to make two Minute Hands and one Hour 


Hand but I still have two smaller thin Walnut off-cuts, though they are only 210mm long which is a little tighter than I would like but holding them with DS Tape will get them done I’m sure.

*26th Dec*
The two off-cuts needed only a short time on the linisher to get a flat, smooth, surface which could take the DS Tape but I still took all day to finish off the last hands.




The centre holes are machined as an ‘friction interference’ fit of 0.2mm on the spindles and the ‘spring slots’ are intended to allow easy fitting and the means to re-adjust the time by simply moving the hands.

*27th Dec*
Now I have the hands fitted to the first ‘mock’ assembly, the Dial needs to be attached but as yet I haven’t made the stand-off pads. They have been left until I can be sure just how much the ‘stand-off’ can be. They were designed at 6mm and measuring the clearance between the Frame and the Dial that may be a little too much so I’ll reduce it to 5mm. Unlike ‘normal’ clock hands which are usually made from thin brass sheet which can be bent, Walnut won’t take kindly to that treatment 

The Pads are another example of a component that is made much easier by having a CNC 


option. They needed to be ‘face-grain’ so a set of simple 20mm Ø circles drawn at the appropriate place in CorelDRAW! produced a .DXF file and ultimately G-Code which cut superb 20mm x 10mm Maple Buttons which were easy to mount on the 4 jaw chuck (Fig-152 - WIP-30) for 2nd & 3rd operations. I’m particularly pleased with the fact that once I’d ‘sized’ the first tenon to fit the recess I could simply ‘dial in’ to the same settings on the lathe and get the same press fit in all the others. In the foreground of Fig-175 there is the 20mm Ø button as it came off the Denford and in the background are the two (marginally) different finished Dial Pads. They are only different because the two Pads at the top line up with the threaded inserts so need to have a clearance recess for them.

*28th Dec*
Now the Dial Pads are in place it becomes very obvious that I haven’t made the Signature Plate that covers the Bottom Spacer Thread Insert, so today I’ve been working on that. It is customary to mark clocks with a full signature or at least a monogram. In my case I mark all of my work - usually with a simple 5mm Ø copper disk into which I’ve stamped my Silversmith’s Sponsor Mark. Due to the limitations of size (2mm high) my mark is a monogram in a simple pentagon. Fig-176 is an endoscope screen grab of the punch but the original version is a ‘fancy’ monogram 


in a Reuleaux Pentagon (Fig-177). After



a number of tests I’ve discovered that unfortunately that can’t be cut into wood - even close grained Maple - and still retain all the detail, smaller than about 2" high so I’ve settled on the compromise of a ‘filled’ version which will finish at 20mm high on a 25mm Pentagon.


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## Yojevol (30 Dec 2020)

Just a point of ergonomics, JG. The walnut hands may get lost against the similar material behind. I'm having this problem on my clock with maple hands in front of the birch ply components behind. It may be worth trying a sample of maple before committing to further manufacture. 
Brian


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## J-G (30 Dec 2020)

Good call Brian, I had considered that issue some time ago (during the design stage) and thought that 'Gold' leaf may be a solution. 

It may still be  even adding gold leaf to the tips might be an option. 

Due to the 'scrap' hands, I have plenty of 'test bed' pieces.


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## donwatson (31 Dec 2020)

Thanks again JG


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## J-G (1 Jan 2021)

I had meant to post this last night but got somewhat distracted 

*29th Dec*
It never ceases to amaze me how long some simple (apparently) little components actually take to make. The Signature plates took all day - well I did have some other bits & pieces to do and had to let paint dry - but essentially with the time taken to set up a location jig and the numerous tests to get the best engraving I didn’t get anything else done. More to the point - they are all scrap!!




I only discovered this when I came to attach one to the mock assembly and was puzzled by the fact that it wasn’t central on the fra


me.


It took me a while to fathom what was wrong and only resolved when I came to photograph two of the plates side by side to demonstrate how they are fixed that I couldn’t align the bos


s correctly.











I thought that I had been meticulous with positioning the various elements (Pentagon, Circle... which are on opposite sides) accurately and also central to the blank which had to be turned over and was surprised when the surface clearing cut was about 1.5mm out. Without much thought, I made an adjustment after flipping the blank so I suspect that that was my main error.

*30th Dec*
I’ve just measured the position of the surface clearing polyline in the CamBam drawing and find that it is NOT central on the blank  There is a difference of about 3mm (I wasn’t looking for micron accuracy!) so that does seem to explain it. 

Since I have to start again, along with the correction of the surface clearing line, I’ve made a few small adjustments to the Monogram which I think will improve the final result.

It looks as though there is quite an improvement. There are now three of the four sitting in the Denford waiting for a final surface clean-up when the paint has dried overnight. Fortunately I watched while the 2mm cutter did the pentagon outline so was able to abort the run when it began to slip out of the collet — how could I forget to tighten it and leave it only ‘finger’ tight??  This meant that one of the holding tabs was removed so during the finishing cut, it broke away.

*31st Dec*



Fig-182 is the back of the ‘One that got away’ (recovered) showing that the mounting boss IS in the correct place and Fig-183 shows the remaining three waiting for the paint to dry before the final skim. I’ve already done a 0.1mm skim but there were depressions in the paint fill so


I’ve applied another coat which will be skimmed again later today.
I think that having the monogram ‘filled’ is better than just a thin film in the depressions.



With just a little experience of the effects of engraving depth and very minor adjustments to the original outline (tenths of a millimetre) it surprises me how much improvement there is to the finished work.

On the left of Fig-184 is the first attempt, which went wrong due to the mis-placed fixing boss, with the deeper cut and surface painted monogram and on the right the second attempt cut only 0.3mm less deep and fully filled with Acrylic Paint.

With the end of the year fast approaching, I’ve reviewed what is still to be done as far as component manufacture is concerned and see that the only parts still to be made are for the ‘Weight’. Though I’m still in two minds as to whether to buy in winding handles, which are standard parts available from the likes of Cousins, the main issue being that I don't have a broaching facility to cut deep square holes.

The Driving Weight has been left ‘til last because until I have a fully assembled clock I can’t be sure how much weight will be needed. I know that it will be made from a clear Acrylic Tube 60mm Ø but the length will be determined by the weight needed and I think that a ‘part filled’ weight would look ‘odd’.

Tomorrow I should start to look at finishing the wooden parts by sanding, applying Sanding Sealer and MC Wax before gluing up the various ‘sets’ of Gears that belong on the same spindle.


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## donwatson (11 Jan 2021)

Thanks JG


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## J-G (14 Jan 2021)

*8th Jan*
First day in the workshop this year - though, to be honest, I have done some ‘fettling’ of the gears while sitting at my office desk and waiting for the PC to finish a task - most of the time has been spent on End-of-Year Accounts and VAT return.

I’ve finished all the CNC machining (well I thought I had! see below) so now it’s a matter of dealing with the surface finish on the Gears and Frame, starting with sanding to 320g, then applying Sanding Sealer, de-nibbing and finishing with MC Wax. 

I’d assembled some of the gears/pinions along with their bearings and taking these apart to do the sanding proved somewhat difficult - even though they had not been glued - and one pairing didn’t want to be parted at all and the Pinion disintegrated. With a second, I pressed the bearing deep into the pinion (with a bench press) such that I’ll have to break that apart to retrieve the Bearing — so, I now do have to do some CNC work to make two more!





The ‘fettling’ that I did at my desk was just cleaning up the Gear Teeth. I made a ‘stick’ roughly the shape of the tooth profile, glued a strip of 240g abrasive to it and simply went around each tooth to remove any remnants of wood fiber that would potentially cause a ‘bind’ with the mating Pinion or Gear.

Taking the photo’ for Fig-185 proved ‘interesting’ -- I only have two hands  ... but I suspect you can fully understand what I was doing.

*9th Jan*
Made two new Pinions but scrapped one by trying to take too big a cut when machining the boss so had to make yet another !!

I still have quite a few Gears to ‘fettle’ and although I made another abrasive stick it really is a chore  This led me to think about a better option which seemed to be a thin ‘flap wheel’ - or, better still - an abrasive ‘worm wheel’.

To sand the faces I’m using 50mm Ø abrasive discs attached to a pad by Velcro so I’ve had an idea to make a disc with velcro on both sides which will take the same discs. It might be somewhat more aggressive than my ‘Fettling stick’ so will need care but I have found 50mm Ø self adhesive Velcro discs which should be with me early next week so I can soon make a thin double sided abrasive disc which I can mount on a rod in the lathe. I’ll have to punch a 20mm hole in the centre of the Velcro & abrasive but that shouldn’t present much of a problem as I’ve previously made hole punches for Copper & Silver up to 10mm.

*12th Jan*
All the Gears have now been ‘finished’ with Sanding Sealer and had a final sanding with 400g so now I can start real assembly.

One of the most important things that I hadn’t made were the Escapement Pins so whilst I was waiting for the sanding sealer to thoroughly dry I made these. I had bought in 3m length of 2mm Ø Stainless Steel and had originally determined to hold that in a 2mm Collet on the lathe and feed enough to part off 14mm long pieces but I


had a better idea. To hold the steel in the lathe I would have needed to cut it into shorter (600mm max) lengths and even then by the time I’d parted most of that length off there would have been a short length that could no longer be held but it occurred to me that I could drill a 14mm deep 2.1mm Ø hole in a block of Aluminium and use that to saw off the 120 pins I needed.

I started by using a Jewellers piercing saw but the 4/0 blade was blunt after only 3. They are intended to be used on Silver/Gold/Copper/Brass etc. so there was no real surprise that Stainless Steel took its toll. Once I’d changed to a small Hacksaw I was cutting them off at a regular length in moments. I also needed 24 off at only 10mm long so a second hole soon sorted that and after a mornings work I had all the pins ready to be pressed into the pre-drilled holes.
The shorter pins are for the Drive Gear Pawls and only 6 in each so that’s where I started the assembly. I’d drilled the holes at 1.9mm Ø since I didn’t want to glue the pins in so I considered a 0.1mm interference sufficient. A problem immediately became apparent when I found that I couldn’t hold a pin above the hole and in a position to apply pressure from the Arbour Press so I had to open each hole out to 2mm but only for the first 1mm. Doing this by hand is not the easiest job I’ve had to do and I broke a drill leaving about 2mm in one of the holes  That took quite some time to get out! In Fig-187 you can see two of the pins ready to have the third Pawl dropped on.




With the holes widened, I could just press the pin in by hand and then use the Arbour Press to force them in leaving the 5mm height I needed.

My next job will be to put 30 in each of the Escape Wheels but I think I need to find a better way to open the holes in them.

My experience with the Pawl Pins made me think to use the milling machine to ‘carefully’ open the tops of the holes in the Escape Wheel. The potential danger would be that the drill might ‘snatch’ which would remove the grip afforded by the original 1.9mm Ø hole. In fact I found it quite easy to just tweak the top 1mm and after I’d done a few I made sure that the pins would hold. Not remembering how many holes I’d actually re-cut, I continued and found that because these pins are 14mm long, it was easy to hold them well enough to hammer them home into the original holes without using the Arbour Press. One end of each pin was still ‘as sawn’, often with a small burr where I hadn’t sawn quite through 


and been able to break the pin off the stock, but I had smoothed the other end off to get it in the jig. This meant that they all needed to be levelled in the same way that I’d sanded the Gears - with the 50mm Ø pad in the mill - but using 60g abrasive with a final skim using 240g.

Fig-188 is the complete Escape Wheel and Fig-189 a close up of the trimmed pins.






*13th Jan*
The glue-up of the Escape Wheel to the spacer and Pinion can now be done but I’d forgotten that the spacer also needed to be finish sanded & sealed!

The fact that the Spacer and Pinion are already mounted on the spindles made it easy to deal with that but I had to strip them for the glue up and ream the bore again to clean out excess glue.

I’ve received the 50mm Ø Velcro discs and made the thin disc sander that I mentioned on Saturday. Using two, back-to-back, would have been ideal but by the time I have even a thin backing card that the Velcro can be glued to it was too thick so I’ve had to settle for a single sided option and go round each Gear twice - turning them over for the second pass.




The rest of today was spent mostly in glueing together the ‘pairs’ of Gears but also finishing off small details that I hadn’t done on the Winding Drums. I still have to make the cord ends so that’s likely to be tomorrow.


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## donwatson (14 Jan 2021)

Thanks JG,glad your back.


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## J-G (17 Jan 2021)

*16th Jan*
Not a lot done to the clock since my last posting, my workshop lighting has been degrading for some time and although I bought new 600mm Sq. LED Panels in Nov.’19 I hadn’t made the time to fit them. With the demise of two more 5' flourescent tubes (or maybe ‘starters’) last week I really did need to make an effort. Since I’d bought ‘bare’ LED units I had to make ‘fittings’. I knew what they would be - very simple 19 x 45 battens with 16 x 16 trunking set in a slot, screwed to the ceiling so that the LED Panel could be slid in from the end. Exactly the same as those I fitted to my new workshop in 2019.

Nothing ‘fancy’ but deciding what suitable materials I had was, shall we say ‘fraught’! I eventually cut the battens out of some floorboard saved when I re-modelled my bathroom but I ha


d to resort to buying some junction boxes to make the connection to the existing lighting circuit ‘safe’. 

I don’t have a fear of electrics - just a sensible respect - but I don’t find working on the ceiling at arms length from a small step ladder the most comfortable  and just fitting one panel took me the best part of three days - I had made enough battens for all three lights though, and much of that time was spent in drawing the new LED fitting in the SketchUp model of my property/workshop. I like to know what I’m doing before I start! 

I eventually got back to the clock this afternoon but I’ve only made the Cord Ends from 4mm Ø Brass rod. These are quite small at 4mm long and have two holes - one at 1.3mmØ and the other at 2.7mmØ. Fig-192 gives a better idea when compared to a 5p coin.




To drill the holes I needed to make a jig which would precisely locate the small billets in the vice on the milling machine. A small scrap of thin MDF with another scrap of hardwood glued to it did all I needed to position the support in the vice and a 3mm deep slot cut with a ball nose 4mm Ø end-mill was enough to locate the brass billet. I had to change the drill with


out moving the blank of course but that’s no great hardship.

Now the Cord Ends are made, I can get on with finishing the Winding Drums.

*17th Jan*
The Cord will need to be about 1.5 to 2m long but I can’t be sure of that until I have a fully assembled clock but I do need to start somewhere so I’ll cut them at 2m.

It will be fixed to the Drum by inserting the brass End into a 5mm hole in the side of the Drum (Fig-194) with the Cord coming out of a 1.5mm slot. Keeping it in place will be an End Cap which is fixed with three wood-screws (2mm Ø x 6mm long).

Threading the 1mm Ø (nominal) Cord through the 1.3mm Ø hole proved to be somewhat daunting. In fact so much so that I gave up after nearly an hour of trying various methods - using glue to keep the stran


ds together, thin wire to bind etc. - and drilled it out to 1.5mm, but also widened the outside by using a centre-drill to provide a ‘cone’ which had a tendency to pull the fraying strands ‘in’ rather than push them out. I still had to make a clean cut with a scalpel though.

The Cord is polyester so once threaded through the small hole it becomes a simple matter of burning the end which melts it and forms a larger ‘blob’ to sit inside the 2.7mm hole.

The Endcap had to have the three screw-holes drilled & countersunk before being assembled to the Drum, after which I could run an 8mm Reamer through to clean up any minor irregularity and mount it on the spindle for final finish sanding, sealing, MC wax and polishing.









Fig-195 shows the part assembled Drum with Cord & Cord-End and in Fig-196 you can see the fully assembled Drum with the Cord wound on. The second Cord-End is threaded on but just held on the Cord with a simple knot. It can’t be finished off until I’ve made the Eyelet that will be the top of the Drive Weight. I will have to ‘un-wind’ the Cord because the grub screw that holds it to the spindle is under it and I have to take it off the spindle to glue the Ratchet to the Drum and fit the Main Drive Gear.


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## donwatson (18 Jan 2021)

Thanks JG


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## J-G (25 Jan 2021)

*18th Jan*
Quite a productive day today - how much that is down to the extra light in the workshop is debatable! - I got the Main Drive Gears and Ratchets finish sanded/sealed/MC waxed and polished. It never ceases to amaze me how good it feels to handle nicely polished hardwoods, the Ratchets are made from African Leadwood and the finish feels like silk. Not that the end user will get to handle the 50mm Ø face now it is glued to the Winding Drum. Equally with the Hard Maple Main Drive Gear although there is enough surface area to handle, it’s not something that would be expected to be touched but there is a certain satisfaction in knowing that it could be.




Regrettably it’s difficult to show the polished finish in a photo, though there is just a hint of a highlight on the rim of the Ratchet in Fig-197.

Now that I have the Drive Spindle assembled I’ve proved that the Ratchet & Pawl system really does work. 

I next turned my attention to the First Train Spindle (this carries the Hands) and was somewhat miffed to find that one of the four which I’d glued up yesterday had the 60T Gear set at about 3° out of square  The only solution was to saw through the spacer, re-cut the recess on both the 60T & 32T gears then make a new spacer. Fortunately I didn’t have to re-make the Gears!

Once I’d re-made and glued this pair of gears - making very sure that they were running parallel - I had to leave them for the glue to cure so turned my attention back to the Main Drive Spindle. I said some time back that I wasn’t sure whether I should buy a commercial Winding Handle or make one from scratch.

Part of the reason for this indecision was the fact that they were available at about £8.50 but also that it is quite a complex item. So, I looked again at the commercial product to both check the cost but also to re-evaluate the design. I soon discovered that the price today is nearly £14 - no brainer! - so I set about designing my own.





The ‘norm’ is to machine a square on the end of the spindle (Fig-198) but that does cause a problem when you don’t have access to a square broach to cut the mating square in a ‘Key’. However, thinking outside-the-box, there is no reason that the drive has to be square, it could be two flats (Fig-199). Yes, a square would keep the key in place but a matching slot can easily be milled in a round bar. 

One problem might be that there would be a tendency for the key to slip off the spindle. A solution would be to put a ‘sleeve’ over the slotted round bar. A further issue might be the ‘thin’ prongs left after the slot had been milled. I think I’ve solved all these concerns, along with some others that I didn’t foresee until I set about drawing both a SketchUp model (Fig-200) & a CorelDRAW! technical drawing (Fig-201). I wanted the ‘Knob’ to be captive but ‘loose’ so I had to make a small change from my original design which had the Spindle (116) as a simple 6mm Ø peg with an 


M4 thread on the bottom which would also act as a clamp for the Arm (114) - to incorporate a hexagon collar for a spanner. On further consideration I may well Drill & Tap the Arm so that the thread on the Spindle goes through it.

Since I don’t have any 10mm A/F Hexagon Stainless Steel ‘on-the-shelf’ I’ll have to visit a local metals warehouse tomorrow. 

To get around the ‘thin’ pegs I’ll make the slot 5mm wide rather than 6mm.

*19th Jan*
No real work done on the clock today, Stainless Steel Hexagon bar bought along with similar Brass which I also needed to make the Vertical Adjuster Screws, other than that, all I got done was the small modification to the Winding Handle drawings - ‘Life’ just got in the way 




*20th Jan*
A long day in the workshop but I only got a prototype of the Winding Handle part made. I still have to finish the base of the ‘Knob’, fully insert the ‘pronged’ part and pin it in place and make the brass plug for the centre of the knob.

Making the prototype has brought some issues to the fore and the next three will be marginally modified. Specifically, the knob has a brass sleeve which is a straight through tube but I now see that it would be better to make it blind so that the fixing does not rely upon a thin sliver of Walnut to retain the Knob on the Spindle. This becomes possible because the Sleeve can be affixed to the Walnut Knob with CA glue.
*
21st to 23rd Jan*
The Winding Handles have all been completed, again with small - practical -modifications.
The original design had a ‘pin’ holding the slotted insert in place but since I don't have any small taper pins I changed that to an M3 grub screw. I also decided to drill & tap both ends of the Arm rather than rely on a simple ‘clamping’ against a milled flat.

The Brass i


ncerts proved to be simple and they are glued in place making the Knob ‘captive’ on its spindle so it is free to rotate but I had to make a thin 10mm A/F spanner to tighten the Knob Spindle to the Brass base.

With 10 components, the Winding Handle is probably the most complex part of the whole clock so no wonder it took be the best part of three days to make the four. Far too much of the time was spent in tapping the Arm – Stainless Steel is much more difficult to work than EN1a and fortunately I didn’t break any taps! I did break 3 Carbide drills and even a 4mm end mill though.  

*24th Jan*
With the completion of three more brass Vertical Adjustment Screws today (now I have the Brass hexagon bar) I think all the components, other than the Weight, are complete so I can’t put off applying the finish to the main frames any longer. The faces had already been sanded to 320g but I hadn’t done anything to the edges so running those against a flap-wheel, some hand sanding where I couldn’t get the flap-wheel in, before a coat of Sanding Sealer followed by a de-nib with 1000g and a final MC Wax, has made them ready for gluing up with the Dial stand-offs and Spacer Brace.


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## donwatson (27 Jan 2021)

Thanks JG


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## J-G (29 Jan 2021)

*25th Jan*
Today was spent going through the various components finish sanding, sealing, waxing, polishing and finally allocating to a particular build. This means that all the less than perfect - or even outright ‘damaged’ but still functional - parts will all be on the one clock. The sorting has brought to light the fact that I’ve ‘lost’ a few components that I know have been made but I’ve been careless and dropped them whilst moving them around the workshop. I now have four containers to store the smaller parts so hopefully won’t lose any more!







*26th - 27th Jan*
Working through ‘fiddly’ bits and pieces which of course take far longer than it seems they should. The Pendulum Rods are now ‘pinned’ to the Escape Wheel Latch/Lift and screwed to the ‘Bob’.

I’ve now started real assembly - using Glue - ie. no easy return to the previous state.

This has been a simple matter of fitting the various pads to the frame though I have also built the Escape Latch support and fitted the Frame Spacers so I can at least show an assembled frame complete with Pendulum. The Bearings are all fitted so hopefully I’ll get the spindles & gears fitted tomorrow.

*29th - Jan*
Nothing done yesterday but today I started by gluing in the Frame Brace and Spacers to the Rear Frame using the front Frame with the Spacing Rods as a clamping mechanism.
Once the glue had cured I could take the frame apart again and realized that I needed to make sure that the Latch & Finger Support was correctly aligned. This is the curved part at the top on which the Pendulum ‘Finger’ and the Escape ‘Latch’ are attached and there is a means of adjusting its position to bring the clock ‘In Beat’ but naturally it would best to have it in a central position to start with. This is achieved by using the two M3 grub screws either side of the Rear Frame which act upon a Brass plate - - - a drawing paints a better picture! - Fig-206.





To achieve this ‘balance’ I had to make sure that the Frame was held exactly perpendicular to the axis of measurement so I lashed up a jig (Fig-207) with which I could measure the position of each ‘pivot’ accurately. That is between the two Red lines, the distance along the black lines must be equal.

That is, under ideal conditions, 


the beat will be Tic-Toc-Tic-Toc not Tic—Toc-Tic—Toc-Tic—Toc - - - - - - or any other variant!

The problem is that once the Clock is in use I have no control over the particular location and a fine adjustment becomes necessary. This is also why there is a fine adjustment for the Pendulum length since Gravity is not an absolute constant geographically.


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## donwatson (30 Jan 2021)

Thanks JG


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## J-G (3 Feb 2021)

The first ‘Build’ has revealed some issues - as was to be expected - nothing particularly onerous but certainly needing attention. There seems to be no problem with the gear teeth ‘binding’ but there is an issue with ‘wobble’ - that is with the Gears not being absolutely perpendicular to their spindles, but it may be more to do with warping or cupping of the timber.

This first showed itself with the Escape Wheel where I designed in quite a small space between the Frame and the back of the Wheel - 2mm - so as it is 120mm Ø and only 5mm thick, a small warp of 1mm should not be unexpected but couple that with the fact that the head of the Latch & Finger Support Clamping Screw stands about 1mm proud of the frame and there will be no clearance 




An easy solution to this was to re-cut the Support Pivot Bush recess 1mm deeper thus putting the screw head at least flush with the frame. In Fig-208, which is a photo’ taken from the top of the frame, you can see that I haven’t given myself a great deal of lea-way.

With hind-sight, it might be better not to rely upon the gears remaining ‘flat’ and finish machine them once they have been assemble on their spindles. I will have to dis-assemble the clock at least once because I still need to cross-drill the 1st Train Spindle for the pin to drive the Hour Hand Gear and the position of that needs to be determined empirically, so I still have the option to true-up the Escape Wheel - and of course there are three more clocks so I can take this new knowledge into account before I do the next build.

After the minor adjustments I was pleased to be able to turn the Main Drive Wheel and see all the Gears & Escape Wheel turn freely.

What is less gratifying is that I can only do so by pulling quite hard on the Main Drive Gear rather than pulling on the Cord. This may mean that the weight needed to drive it may be much higher than the estimated 2kg 

*30th Jan*
I got my Grandson to pull on the cord with me holding the Clock Frame and it seemed easier to get the Gears moving and I’ve now found a space in my workshop where I can fix the Wall Plate and therefore ‘hang’ the Clock for the next series of tests.

My first test was with a 1.7kg bottle of water which needed a little persuasion (by ‘flicking’ the Escape Wheel) to get any movement but it was no more than about a ¼ turn of the Main Drive Wheel. Changing to a 3kg bottle did get it to completely unwind the winding drum but it took between 4 and 5 minutes to do so. I also became aware that with that weight there is a tendency for the right hand wall anchor to lift out of the key-hole slot in the Wall Plate so I’ll need to design a locking mechanism to stop that.

Finding a lump of steel weighing about 2kg I lashed that to a (currently unused) part of my Myford 7 which brought the weight up to just over 4kg. This was less than successful since the left hand Wall anchor broke ! The main reason for this was that I had been less than fastidious when gluing it to the frame so it was only held in by a tenuous 5% of the circumference with no glue on the shoulder. The fact that I didn’t remove the wax polish first may also have been a contributing factor!! 




Due to the right hand Wall Plate button lifting, I needed to design a locking device. It made sense to devise a ‘cam’ locking which could be lifted out of the way to allow the clock to be mounted and locked down again once in position. As the Brass ‘Key-hole’ plates are held in a recess in the Wall Plate with two screws it also seemed convenient to use the top one as the Cam axis by fitting an M4 Thread Insert where it is currently a wood-screw. Fig-209 shows the right hand end of the Wall Plate with an outline of the Cam, open & locked. This was a simple matter to CNC out of 3mm thick Tufnol but I still had to do the job twice through stupidity! ie. not checking the location of the blank after re-clamping. Now I have to re-make the Mounting Block which broke so that I can test how effective the Locking Cam is.

*31st Jan*
Since the new ‘Locking Cam’ is only 3mm thick and the recess for 


the screw head can therefore sensibly be only 1.6mm deep, I can’t use standard button head screws, the standard head is 2.3mm thick and 7.7mm Ø so I had to modify them – a simple matter on the lathe but still taking time.

Cutting the hole for the M4 Thread Insert was also a simple matter, using the existing countersunk screw-hole in the Brass plate gave ample positional guidance and once that had been opened up to 4mm I could remove the plate and drill the 5.5mm Ø hole and 8mm counterbore needed for the Insert. One small bone of contention is the depth of the hole - - - I need the screw to ‘bottom out’ before the Cam is clamped tight and can’t swivel and that could be a matter of just a few tenths of a millimetre. There seems to be two ways to deal with this, either trimming the length of the screw or adding a small piece of steel or brass to the bottom of the hole.

Before I deal with that, I’m thinking about why it seems that I need a 4kg weight to drive the clock. One thing that occurs to me is that there may well be a pressure on the ends of the spindles created by the spacers being just a little short - or possibly that the Bearing recesses have been cut a little too shallow - either scenario would have the same effect. The fact that the Frame Clamping Rods seem just a bit too long seems to bear this out.

An easy way to test this would be to add a ‘washer’ under each Spacer. It cannot be too thick so a sample of Formica at 0.7mm thick might just be enough, but I could add two if one made little improvement.

An interesting morning, discovering some of the errors made early on in this project! The addition of the thin washer did wonders for the ‘weight’ issue – along with a small adjustment to the Escape Wheel to correct some of the ‘wobble’ - and I had a complete unwind of the drum with a 1.5kg weight.

I said ‘some’ of the wobble - - the Pins were meant to go in 4 of the 5mm thickness but I’d obviously been a bit too heavy handed and taking just about ½mm off exposed some of them. In case that ½mm wasn’t enough, I decided to take a further ½mm out of the Spindle shoulder. The potential repercussions of this would be a possibility that the Pinion wouldn’t align with the Gear but since they are both 5mm wide, pushing it ½mm along the spindle is not a serious issue.

After re-building the clock I mounted it on the Wall Plate and a further ‘free-fall’ test proved positive with no ‘rubbing’ between the Escape Wheel & the Latch/Finger Support.

Now came the acid test - with the pendulum.

Not 100% - in fact I had to increase the weight to 2kg before I got any useful power and even then it was very ‘hit & miss’ getting no more than about 15 seconds. After some investigation it seemed that there wasn’t enough power being past to the ‘Finger’ which is what the Pendulum needs. There was also an issue with the Latch not lifting quite enough to release the Escape Wheel. This last point is exacerbated by the fact that the Escape Wheel is not perfectly concentric with the Spindle - - it’s no more than ¼mm but that is a huge amount when the total lift on the Latch is only 1mm!

Stripped the clock again and mounted the Escape Wheel - on its Spindle - in the lathe and trimmed the top until all the teeth had been affected. I took off about 0.3mm from the highest tooth. Whilst I had it in the lathe I took the opportunity to apply some pressure to the Pins since some of them are just off being perpendicular.

With this ‘hind-sight’ knowledge, I think that rather than drilling the holes for the pins at the same time as I cut the teeth on the Denford, it would be better to leave that until the Wheel is mounted on its spindle and drill them on the lathe using an index wheel or on the Mill using a dividing head - it would be more work but guaranteed to be accurate. If the Escape Wheel were made of Brass I suspect that there wouldn’t be any problem.

Now I’ve done the same adjustments to all four Escape Wheels, it’s interesting to note that two of them had virtually no ‘wobble’ but one of them had nearly 3mm ! and that one is the first one I made! It was built from the 5 segments which I did thinking that it would be a way to eliminate some potential problems - obviously not!

I did lots of ‘fiddling’ with the Latch-Lift/Finger by adding bits to both and trimming the added bits back but still no real improvement. The one thing that did make a difference - and effectively changes the position of both the Finger & Latch-Lift - was to adjust the Pivot Screws. By screwing 


them further in, both the Latch-Lift and the Finger are raised changing the relative position of the Finger ‘tip’ to the Escape Wheel Pins and this certainly had a positive affect and I got a Pendulum swing lasting about 4 minutes.

*2nd Feb*
After a few attempts at cajoling the Pendulum to swing longer by increasing the Weight to 3kg and further adjustments to the Pivot screws I took a more pragmatic approach and made a pencil mark on the Gear Teeth when the Pendulum stopped. By now I had fitted the hands so that I could judge how long the Clock had been ‘going’ and it had achieved over 7 minutes.

It was good to find that it stopped exactly at the same position on three occasions which meant that there is certainly some binding between the Second Train Gear & Escape Train Pinion so I stripped the clock yet again and trimmed the 10 teeth either side of the one that was marked. I also mounted the Gear & Spindle in the lathe to check that the O/D was concentric and it turned out that the tooth with the pencil mark was about 0.3mm higher than the lowest tooth and was soon trimmed to concentricity. Likewise, I tested, and corrected, the First Train Gear which had a smaller difference.

After re-building the clock and mounting it for further tests, adding the weight seemed perfectly normal but after a few swings of the Pendulum it plummeted to the ground!!! It was disappointing to discover that two of the retaining pegs on the Pawls had broken away allowing the Winding Drum to ‘free-wheel’.





Fig-212 is the outline drawing of the Pawl and Fig-213 is the broken Pawl.

Since the Pawl is such a small component I suspect that I could have foreseen this possibility - - it doesn’t make it any more palatable - - but I think that making the replacements from Tufnol may be a better option, though increasing the size of the retaining peg (al la Fig-212 dotted red line) could be a way to maintain the ‘Wooden’ element. I’ll make that decision tomorrow.


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## donwatson (3 Feb 2021)

As usual a big thanks for this JG. Working on this project looks as if you have hit quite a few running problems/glitches and I find it interesting to see how you solve them. Good ideas you have on problem solving, keep up the good work.
take care and stay safe
Don W


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## Yojevol (3 Feb 2021)

Your latest niggles sound very familiar JG. 90% of my similar problems were associated with the escape wheel where the available torque is at a minimum. I took particular note of your gearwheel having a 0.3mm ovality. I have experienced exactly the same error on my first attempt at gear cutting on my Denford. I ran a few tests to find that I am getting constant errors especially in the X-axis. I've now found that I've got a 0.3mm backlash in the leadscrew and measurable wear in the guides which is giving smaller errors in the Y direction. I've opened up a thread on the Denford forum which you may be interested in. Also seeking advice here. I'm making some headway in resolving the issues.
Brian


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## J-G (3 Feb 2021)

donwatson said:


> Working on this project looks as if you have hit quite a few running problems/glitches and I find it interesting to see how you solve them. Good ideas you have on problem solving


Thanks Don. When I started this WIP I did say that it would be 'my take' on what a WIP should try to do - that is, catalogue the errors made and show how they are circumvented.

I have no illusion that I'm immune from error and probably make more than most since, even though I do always work though potential issues by creating 3D drawing well before I cut any material, it is often not until the manufacturing stage that an unforeseen 'issue' comes to light.

In the case of a clock there are some components where the tolerance to error is extremely small and the Escape Train is certainly one of them. 

The fact that the Pawls have shown that they need a much greater strength than I originally thought is just part of a learning curve and could only have been predicted if I had real knowledge of what forces would be likely to be applied, along with details of the shear-strength of potential materials, rather than a gut feeling that "Beech ought to be OK"


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## J-G (3 Feb 2021)

Yojevol said:


> Your latest niggles sound very familiar JG. 90% of my similar problems were associated with the escape wheel where the available torque is at a minimum.


I wish I had the maths knowledge to be able to determine the amount of Torque available! I know it is only a matter of determining the Mechanical Advantage at each transfer of power and for each Gear/Pinion combination that isn't too onerous but when you get to the Latch/Finger/Pendulum arrangement that's a whole different ball game. Couple that with the fact that when I did an ONC as part of my apprenticeship, I only just scraped through on the 'Mechanics' section with a 39% being re-assesed to 40% - (the 'pass' mark).



Yojevol said:


> I took particular note of your gearwheel having a 0.3mm ovality. I have experienced exactly the same error on my first attempt at gear cutting on my Denford. I ran a few tests to find that I am getting constant errors especially in the X-axis. I've now found that I've got a 0.3mm backlash in the leadscrew and measurable wear in the guides which is giving smaller errors in the Y direction. I've opened up a thread on the Denford forum which you may be interested in. Also seeking advice here. I'm making some headway in resolving the issues.
> Brian


I had noticed your posts about the potential use of Nylon Rod as a replacement guide material but didn't have a reasoned opinion to contribute. I would say though that I would be cautious about 'gluing' any material into the slide carriers. A mechanical fixing can always generally be reversed in the event that it is ineffective.

In my case I don't think it - necessarily - is the same, and it's not 'ovality', which would mean that the error would have two high points at 180° apart and similarly two low points. Mine is more a fact that the centre hole is not 'centred' and since the hole was machined on the lathe with the Gear being held in a pre-machined, and therefore total concentric, set of jaws, I suspect that it is more to do with the natural movement of the Maple.

The link to the Denford Forum is useful thanks - I hadn't looked for one - and I've already down-loaded the Feeds & Speeds .pdf which I'll look at shortly.


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## J-G (4 Feb 2021)

*3rd Feb*
Making small adjustments to existing drawings within CorelDRAW! is very easy but still seems to take forever. Adding the bulge indicated by the dotted red line in Fig-212 appeared to be the best option - whatever the material I choose - and by adding that it would also be necessary to increase the bulge at the top so that the weight is sensibly distributed because the Pawls are only kept in contact with the 


Ratchet due to gravity. In Fig-214 you can see the outline of the new Pawl in red compared to the old Pawl (dotted blue). The geometry of the main part is naturally not changed.

Considering the options open to me as far as the material with which to make the new Pawls, I was concerned that - now I know the Drive Weight is likely to be in excess of 3kg, (I had originally anticipated about 2kg or less) - Mapl


e, Beech, Ash, Oak, Elm etc. are unlikely to be strong enough to withstand the forces involved for very long. Other options are, Tufnol, (a Phenolic Resin Laminated material which essentially has no ‘grain’), Brass or Aluminium.
The later two probably could be cut on the Denford but I’ve not yet dipped my toe in that water so I settled for Tufnol and the result can be seen in Fig-215 where the Pawls are mounted on the Main Drive Gear.

As there had been damage to the Pawls I was not at all surprised to find that when I dismantled the Winding Drum from the Main Drive Gear, there was also damage to the Ratchet. That is quite difficult to photograph so I’ve done some enhancements to Fig-216 where the Yellow line shows where the Ratchet teeth should be (were!) and the red lines indicate the damage which amounts to three of the teeth.




The Ratchet is already glued to the Winding Drum so affecting a repair to this is going to be fraught with issues.

I could make a new Ratchet and destroy the existing one by holding the Winding Drum in the lathe and machining it away but I think that inserting Brass ‘Teeth’ would be preferable. These might be glued into radial s


lots which could be cut using an engraving MOP using the blue lines in Fig-217.
One problem with this is that I need to find a way to hold the assembly which is the Ratchet & Winding Drum on the Denford Table so that the Ratchet is uppermost but the bottom of that assembly is only 12mm Ø.
The centre of the Denford Table has an M6 threaded insert so I made a locating peg to fit the centre of the Winding Drum with an M6 thread on the bottom and an M5 thread at the top. This would ‘locate’ the Ratchet but wouldn’t hold it well enough to handle cutting the slots for the Brass teeth so the possibility for it to move would be high. 
Next I bored a close-fitting hole in a block of Oak which can be clamped to the table and milled a slot into which the M3 Grub Screw which clamps the Winding Drum to the Drive Spindle can fit thus arresting any potential movement.



*4th Feb*
The Ratchet is now positioned on the Denford Table and Fig-218 shows it with a 2mm Ø burr at X0-Y0 but I’ve just realized that I haven’t taken account of the precise orientation of the Ratchet Teeth . . . . . This is going to be important because initially I’m thinking of just inserting Brass teeth at the position of the three broken ones might do the job.

. . . . . . Now I have correctly aligned the block, I’ve noticed that a fourth tooth has some damage so that will also be replaced.

One of the issues I’ve become acutely aware of, as far as CNC Machining is concerned, is having the work-piece held firmly. Any possibility that it could move during a cut is pretty much certain that it will move and cause damage to either the work or the cutter - or even both! So, I was well pleased to find that this set-up worked very well. In Fig-218 the clamps are gripping the Oak block by about 2mm - they were firm enough but when I re-aligned it to correctly orient the Ratchet Teeth I increased this to nearer 6mm and it was solid as a rock.

Using a DOC = 0.5mm limited the stresses and the four slots were perfectly positioned. Making the Brass teeth was just a ‘fiddle’ at 5mm x 9mm x 2mm and one end rounded over but they were easily 


glued into the slots with CA, left for 10 minutes before mounting the Drum in the lathe and taking cuts of about 0.2mm soon got all the Brass Teeth at the same height as the wooden ones.

This of course left them 2mm wide with no relief and filing the back away when the length of ‘stroke’ for the file was only 7mm was interesting. 

Doing ‘repair’ work might be interesting in-as-much-as it is always a one-off job and often needs ingenuity, but it does take an inordinately long time! It may well be that I could have re-made the complete Ratchet in less time but the chance of similar damage would still be present.


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## Yojevol (4 Feb 2021)

JG I'm surprised you think the required weight is going be 4Kg or more. That is going to add directly to the loads on those pawls and ratchet teeth. Have you tried assembling the clock in stages and test running it at each stage? This gives a better idea of where any unwanted friction is might be arising. At each stage of assembly the gear train should be stopped and started to simulate normal running speed. Slow intermittent motion is much more onerous than just letting it freefall.
Brian


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## J-G (5 Feb 2021)

Thanks for the input Brian. With my last run, most of the tests were with 2.6kg and was getting 7 to 8 minutes, only later moving to 3kg, and suspect that the damage was caused earlier so after the latest round of adjustments I hoped to get more.

As you'll see from the latest post, I've not got as far as re-building so no further real tests have yet been done.

I can't quite see what you mean by 'running at each stage'. Without weight, I have both 'spun' the Escape Wheel and pulled on the Main Drive Gear - to also make the Escape Wheel spin (both equivalent to 'free fall') but I've also gently rotated the Second Train Gear which I suspect is more akin to the 'normal' action and didn't 'feel' any resistance at a specific point.

I have tested each Gear/Pinion pair but not with the frame firmly bolted together so that may well be a sensible ploy.

I've also added weight to the Pendulum Bob but there didn't seem to be any benefit to that.


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## J-G (6 Feb 2021)

*5th Feb*
As suggested by Brian, I made a point of testing the ‘free-flow’ of each pair of Gears/Pinions by applying as little pressure on the gear to just make them move and therefore to see if there were any further ‘high spots’ which would be likely to need more torque to overcome the resistance. As I found them, I marked the teeth with a pencil and judiciously trimmed the flanks until such time as I had a full rotation with no binding.

Spent most of the day either making very small adjustments to either the Pendulum Pivot height, yet more judicious trimming of the tooth flanks or simply pondering over what else might be inhibiting more that a couple of minutes continuous run.

Finally gave up and got on with ‘life’ 

*6th Feb*
First thing I did today was check the Pendulum Pivot height and a very small adjustment seemed to show that the clock would run for over 20 minutes (using a 2kg weight) IF I constantly made sure that the Latch remained in position - that is centred over the Latch Lift. There was a tendency for it to move backwards and eventually get out of the reach of the Lift.

The Latch is constrained on a 2mm pin with a friction fit Acetal ring acting as a retainer but it obviously has to be totally free to move on its 2mm Ø Pivot Pin so the hole is 2.1mm. The Pin is held in the support by friction since the hole was drilled at 1.9mm but if the hole is even marginally out of square then there will be a natural equilibrium pushing the tip of the Latch out of position. This ‘tendency’ can be eliminated by a small re-alignement of the pin which is what I did with a pair of Pliers!

Of course this meant that I had to dismantle the clock again so whilst it was dis-assembled I took the opportunity to make other adjustments. I particular I took a further 1mm from the shoulder of the Escape Wheel Spindle giving yet more clearance between it and the Latch Support and better aligning the Latch with the centre-line of the Escape Wheel. I also sanded the flanks of the teeth on the Second Train Gear both sides which - since I’m using 1000g abrasive - is effectively polishing them but doing the same to the mating Pinion is very difficult because that is glued in place such that there is only about 10mm space so I can’t do it with the 50mm Ø disc. - - - - I think I’ll have to make a small round abrasive ‘stick’ that will fit the Dremel.

Before that, I re-built the Clock, hoping that I would see at least 20-30 minutes running - - - - No more than 2  - - - - even after re-tweeking the Pendulum Pivot height.

It seems that the 2kg weight is insufficient but when the bottle with 3kg fell to the floor, it ruptured and I don’t have another bottle large enough.

When it stops, the Pendulum is still swinging for some time but the Escape Wheel is stationary so that indicates that there is still some binding between the Gears/Pinions so ‘polishing the Pinions’ could well prove to be the answer. It may also be that the Main Drive Gear and the First Train Gear that is driven by it needs ‘polishing’. . . . . . .
After yet another strip-down, ‘fettle’ & re-build I still can’t get a regular long run  I did have one session approaching 30 minutes but most trials ran between 1 & 8 minutes but the biggest disappointment is that there is no consistency. I’ve done tests with and without the Pendulum ‘Bob’ - just using the brass adjusting screw to provide some weight. This effectively shortens the Pendulum length to well below the 1 metre but I wanted to know if the weight of the ‘Bob’ was too great (it may not be), and I’ve also added a lump of steel weighing 1kg to the Weight making it 3kg overall.

I was able to take a Video lasting nearly 3 minutes (it can’t be added to the .PDF of course) but I had to install a Video Editing program to turn it through 90°. Due to its size I then had to trim it so there is just one minute.





Your browser is not able to display this video.


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## donwatson (7 Feb 2021)

Quite a bit of work there JG. Much the same place I was when I abandoned my efforts to make a clock. There seemed to be no consistency in what happened and when it happened. Wish you much good luck in sorting it out.


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## J-G (17 Feb 2021)

*17th Feb*
Though I haven’t reported my activity for a fortnight, I’ve not been idle - though I have spent more time thinking than doing!

Yesterday I had the clock going for nearly 12 hours and it only stopped because the temporary weight reached the floor. Today - up to now - it has done nearly 10 hours so I’m satisfied that the changes I’ve made latterly have been useful.

The main change has been to the Winding Drum. My original design called for 25mm Ø but I’ve now made a secondary Drum 50mm Ø. My calculations show that this ought to provide twice the amount of torque to the Escapement Finger but will of course halve the time between winds - at least I have a working clock!

I also re-cut the 64T 2nd Train Gear - somewhat of a challenge since I had to very accurately re-mount it (them) on the Denford (sorry didn’t take photo’s) making sure that the teeth were correctly oriented. This entailed making a jig to screw into one of the locating screw inserts in the Denford table and four clamps to make sure there was no movement. I only took off 0.2mm from each tooth flank but I also cut the root 0.5mm deeper.

The Red Line in Fig-220 is the new profile and the Blue Line is the original. I suspect that removing the 


‘bulge’ in the addendum has had the most impact.

With the new profile, and the original 25mmØ Winding Drum, I was still getting less than 5 minutes run time with seemingly random stopping positions.

Now I have to turn my attention to the real ‘Drive Weight’.

I had plucked ‘about 2kg’ out of the air as a starting point and with that in mind had determined to use steel inside a clear Acrylic tube. Now I’ve found that it really needs nearer 3kg - and I suspect that 5 or even 6 would have been necessary had I stuck to the smaller Winding Drum - I’ve been looking today at Lead Shot. As you may well understand, there are certain restrictions on the use of shot which is used mainly to fill shot-gun cartridges - or, in small amounts, for fishing weights. After some hours searching for ‘sensible’ sizes and prices it seemed unlikely that I could get the 12kg in good size shot - - - I have learned a great deal about the way that shot is measured though  - - - one site even suggested that to use it for anything other than ‘Fly’ tying would be illegal ??

Eventually I came across a ‘Sash Window Weight’ available in 50mmØ, 600mm long with a 12mm bore and weighing 12.7kg at a little under £60 plus carriage (not determined). Further searching with this new possibility found one supplier at £51 delivered and another at £37 + carriage which I’ve asked them for.

This will be ideal since I won’t have to drill an 8mmØ hole through 150mm of steel and one weight will give me enough for all four clocks. I’ll still use the Acrylic Tube with Walnut caps to cover it and may even use ‘Plasticote’ to further encapsulate it, totally sealing it from any possibility of both tarnish and environmental hazzard.

*18th Feb*
This morning I could determine how long the clock had gone for because naturally the weight had dropped to the floor and it was 21h 25m . This is with a drop of 1.3m whereas the design height should provide 1.5m, in which case I anticipate that I will get close to 25 hours. I can’t yet fathom how this can be since my original calculations predicted 26 hours but I thought that doubling the diameter of the Winding Drum would halve the run time - - I’ll have to do some more calculations!

Yesterday I was using a Weight of 3.048kg made up of a water bottle + a lump of steel and had also added an extra weight to the Pendulum Bob but in an attempt to remove some of the ‘trial adjustments’ today I took both of the extra steel lumps off and it looks as though it will work with a 2.2kg weight. I re-started it at 10am, it's still going and I've just checked and it shows 13:15 which is 5 minutes slow. I know that the Pendulum is too long because I have used a full 1m length of carbon fibre tube for the Rod but at least I now do have a 'benchmark' for proper adjustment. It's a pity that I can only test modifications in 'Real Time'.

The Lead Weight has been ordered and will be with me tomorrow so I can get on with making the other parts.


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## donwatson (18 Feb 2021)

Thanks JG, I thought you must have been busy making some adjustments.


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## J-G (18 Feb 2021)

I've just done an [Edit] to my last post and changed the .PDF so you may want to download the new version.

Good to be moving forward again


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## Yojevol (18 Feb 2021)

J-G said:


> I re-started it at 10am, it's still going and I've just checked and it shows 13:15 which is 5 minutes slow


@J-G It's fairly easy to calculate from the pendulum formula the amount to shorten it by. If it's 5mins slow after 195mins running it will need shortening by about 26mm (assuming G in your neck of the woods is 9.81)

Interesting source of lead - ready made into suitable size cylinders. I've been using scrap lead flashing and casting it but finding something to cast it into is not easy. 50mm drinks cans are common but that was to large for my recent clock. A source of lead shot in small quantities is the aqua-lung diving community. You can get 2Kg packs which they use. 
Brian


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## J-G (18 Feb 2021)

Yojevol said:


> It's fairly easy to calculate from the pendulum formula the amount to shorten it by. If it's 5mins slow after 195mins running it will need shortening by about 26mm (assuming G in your neck of the woods is 9.81)


I'm sure it is Brian, I just haven't done the work 

I know g at 52.5725ºN and 92m above Sea Level is 9.81269 so I have done that much previously.



Yojevol said:


> Interesting source of lead - ready made into suitable size cylinders. I've been using scrap lead flashing and casting it but finding something to cast it into is not easy. 50mm drinks cans are common but that was to large for my recent clock. A source of lead shot in small quantities is the aqua-lung diving community. You can get 2Kg packs which they use.
> Brian


I did look at a number of sources and after some research thought that it would be good to get AAA shot which is 5.16mm Ø but I could only find that in small quantities and always 'split' - presumably for quickly attaching to fishing line - the SCUBA community seem to use much smaller shot (#6 2.5mmØ) which has had more work done to it so is therefore more expensive (have I mentioned that I'm a tight-wad?).

The Sash Window community appears to be a better option with most offering 25 & 50mm Ø x 600mm long but also square section and I did find one company offering 'make-weights' which are shorter lengths which may suit you better - since I'm making four I can use most of the 600mm length.

Mine is coming from Mighton (the cheapest) - here's the link to their [Round] list





__





Round Lead Sash Weights


Lead Sash Weights from Mighton. Our lead sash window weights are available in a variety of sizes. All our lead weights are available to buy online with next day delivery.




www.mightonproducts.com





Having a solid lump with a pre-cast hole is a much better option for me and I'll make a sleeve using some Sycamore veneer that I have on the shelf so it won't matter if it tarnishes - it simply won't be seen.


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## Yojevol (18 Feb 2021)

@J-G The other method I have played with is to cut a length of flashing and roll it up tightly into a cylinder. Easier done with new rather that scrap sheets.
Brian


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## J-G (18 Feb 2021)

I had thought about Flashing but didn't look far enough as I thought that H & S had virtually wiped out the use of Lead for flashing due to the potential contamination of rainwater.

A quick Google finds Calder Industrial have a 100mm x 6m roll 1.8mm thick at £33.70 + carriage and that would weigh 12.25kg so a similar cost to the Sash Weight I bought, and it could well be more convenient since the weight could be adjusted by controlling the number of 'turns' used. They also do 150, 180 & 200mm wide.


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## Yojevol (18 Feb 2021)

My neighbour had a wide gully between two roof pitches relined recently. I was amazed to see them lifting a roll, which must have been 800mm or so, up the ladder!


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## J-G (22 Feb 2021)

The Lead did not arrive on Friday and FedEx are showing 'Delivery Schedule: Pending' ??? so I'm hoping that it will appear sometime on Monday.

In the meantime I have now made three of the 'Weight Shells', well the tube, caps and 



hangers are made but I’ve only made one of the bolts.

I’ve held off making the other bolts simply because as yet I’m not convinced that a 2.2kg weight will be sufficient and the length of the bolt (and the tube) may need to be increased. I say this because the clock has been erratic over the past few days, seldom getting past 5 hours run-time but yesterday I increased the drive weight to 3kg and have - up to now - had close to 8 hours and counting.

I assume from this that I will certainly need more than 2.2kg but maybe not as much as 3kg so I’m thinking that I ought to at least allow for some extra. If there is some space above the Lead filling it won’t matter but at the current length of the tube & bolt I can only get about 2.35kg. Adding 15mm to the current design will increase that to 2.68kg.

On a separate matter, a strange thing is happening to the Pendulum Bob. I noticed a while ago that the orientation of the Bob was ‘rotated’ but initially thought that I must have accidentally knocked it out of position so I then made sure that I checked that before I started the next test. Three hours later I saw that the Bob had rotated about 60°. Whether this is due to some natural phenomenon or the fact that I hadn’t fully tightened the Pendulum Rod to the adjusting screw I’ll have to fathom during more tests.

I haven't done a .PDF of this, I'll add it to the next post.


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## Yojevol (22 Feb 2021)

J-G said:


> Three hours later I saw that the Bob had rotated about 60°


I'm not familiar with the detailed design but could the bob be rotating itself down the adjustment screw thread under gravity?
Brian


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## J-G (22 Feb 2021)

Hi Brian, I do keep forgetting that I haven't shared the detailed working drawings - there are rather a lot of them 

Here's a drawing of the Bob along with how it is attached to the Pendulum Rod.




The 'Front' view shows the Rod, Connector & Screw expanded so you can see that they are separate parts and the 'Side' View shows them in their final position. I've also drawn in a possible solution in the shape of a locking screw which would be an M4 grub screw at the back of the Bob - I'm somewhat cautious about taking this approach since the fact that the Bob is 'locked' to the Rod could be forgotten if ever there came a time to make adjustments.

There is no possibility that the Rod could 'rotate' because it is pinned to the Latch/Finger/Pivot mechanism at the top so a grub screw against the Rod in this way would fix the orientation permanently.

I doubt that the Bob is winding itself down the Adjusting Screw but it is possible that the Connector is being unscrewed from the top of the Adjusting screw. A dab of LockTite might well stop that.

My first thought was "could this be the Coriolis Effect?" which is the reason that I use two pivots rather than one but the time-scale seems wrong - and in fact the twisting has never gone beyond about 60°.


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## Yojevol (22 Feb 2021)

I would say it is unscrewing on either the connector thread or the adjustment thread and then the walnut binds up stopping it going beyond the 60°. Coriolis effect is extremely small and would be difficult to detect here.
Brian
PS have you checked whether the nut is rotating as well?


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## J-G (22 Feb 2021)

I did say my 'first thought' was Coriolis - but it was sensibly dismissed 

No I haven't yet marked the nut to detect movement so that's a good 'heads-up' and I'd agree that the restriction to 60° could well be a 'binding' - the screw is M6 and the hole is ¼" Ø so there isn't a lot of clearance.

I now have the Lead so can swap the temporary water bottle weight for the real thing - which has a total weight of 2.56kg inc. Caps, Tube, Screw & Cord Anchor - and do some more tests.


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## J-G (26 Feb 2021)

*25th Feb*
I’ve already reported that the Lead arrived on Monday and I have a total weight of 2.56kg which over the past few days has kept the clock running - with 3 re-winds - for nearly 2 days. I’m sure it would have continued for as long as I re-wound it but it seemed sensible to move on by shortening the Pendulum Rod so that I could do better tests/adjustments to the Pendulum length to improve the accuracy.

There is potential for 50mm of adjustment within the Adjusting Screw so I first took 60mm off the Carbon Fibre Tube. You’ll see that the Brass ‘Connector’ was epoxied into the Rod; this was advised by the supplier since they considered that it would be unlikely that a thread would remain intact. In fact this is the reason that I used a ‘Connector’ rather than screw the Adjusting Screw directly into the Rod. 

Well - since I had a short length of CF Tube to use for a test - I did actually tap it 4BA. This was selected because the bore is 3mmØ and 4BA is 3.6mm OD and 2.81mm ID. It turns out that the Carbon Fibre does stand up to being tapped so I’ve made new Connectors with 4BA threads.



I’ve found a means to ‘Lock’ the Pendulum Bob to the Rod that isn’t as intrusive as a hidden grub-screw. All it needs is a friction device and with the Carbon Fibre Tube is 5mmØ and the hole in the Bob is ¼” there is a 1.35mm gap into which I can insert a ‘Wedge’ (Fig-222) which I’ve made from sliver of Maple. This has the advantage that it will simply loosen if the adjustment is longer (slowing) but would make the adjustment feel ‘stiff’ if it needed to be shorter (speeding) but wouldn’t prohibit any change in the way that a grub-screw clamping that I suggested in my post on Monday would.

Rather than modify the Pendulum that had been in use, I modified one of the other three – this taught me a number of lessons – First, I couldn’t get the clock going for more than a minute. The relationship between the ‘Latch’ - ‘Finger’ - ‘Pivot’ and ‘Escape Wheel Pins’ is extraordinarily delicate and despite ‘fiddling’ with the tips of both the Latch & the Finger, nothing seemed to improve matters.

Eventually I decided to modify the Pendulum that had worked for two days and immediately had it back running for an hour. The fact that it had been running for two days proved (to me) that at least there was no problem with gears binding nor with the Weight not being big enough, so the issue had to be down to the Escape Train geometry. After many attempts to find that ‘Sweet Spot’ - without success - I left it for another day!

There is some good news about the Lead weight - - - - Mighton Products had been excellent in their dealings so I thought it pertinent that they should know of the delivery issues so I sent detailed feedback purely to make them aware that FedEx has failed in their ‘Next Day’ service. Surprise, surprise – within 2 hours I had a promise of a delivery charge refund which materialized the following day!! This was prior to their knowing whether they could make a successful claim against FedEx. This is not just an inconsequential amount of a couple of pounds, it amounts to ~23% of the cost, nearly £12 so very welcome.

*26th - Feb*
During my attempts to get the second 


(shortened) Pendulum working, I had made changes to the ‘Beat Adjuster’, so, as I anticipated, the clock had stopped after less than 10 minutes. This made me take a more ‘scientific approach’ to the Escape Train geometry. Essentially, with the Pendulum ‘At Rest’ the tips of both the Latch and the Finger should just touch the Escape Tooth and Pin respectively - see the red circles in Fig-223 - so I spent some time this morning re-setting the Beat Adjusting Screws along with the Pivot Adjusting Screws to achieve this configuration.

With just a very slight nudge to the Pendulum Rod, I knew within a few seconds that I’d been successful - the ‘tick’ was in beat !

Now, at last, I could turn my attention to the calibration of the pendulum length. I had wound the Adjusting Nut right to the top of its potential travel and after only half an hour I could see that it was 2 minutes fast so I wound the Nut down about 10 turns and re-set the hands. Again there was a perceptible gain after another half hour so I marked the Adjusting Nut and made an accurate 2 turn adjustment. After 4 hours it was showing about 2½ minutes slow. I’ll leave it for a while before making any further changes but at least it seems that I’m moving toward a working and accurate time-piece in an orderly fashion. More importantly though I think I now know how to set the Escape Train up ‘by eye’.

-----------------------------------------------------------------------------------------------------------
The attached .PDF file includes the posting from Monday.


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## donwatson (27 Feb 2021)

Thanks JG


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## J-G (3 Mar 2021)

*2nd Mar*
It seems that I spoke too soon 

Due - I think - to the change in the weather, certainly here it is a few degrees warmer and probably more humid than of late, it seems that the second train main gear has distorted and become ‘oblate’. I only know this because I eventually made a point of marking the 64T Gear whenever the clock stopped, that is every few minutes!

After about twenty or so restarts I was able to notice that there was a preponderance of marks at 180° to each other.

I had by now re-located the clock from my workshop to my office so that I could more frequently check how the timing was progressing without constantly moving to and from the workshop. This meant that I had to dismantle the Pendulum and re-attach it in the new location which meant that the delicate geometry between the latch/finger/pivot was upset so I needed to make small adjustments (I think I need to find a way to ‘fix’ the pivot screws once I have them at the correct position). Because I had been making small - I’m taking less than a ¼ turn of an M3 screw - adjustments to the ‘Beat’, as well as the pivot screw positions when trying to find that ‘Sweet Spot’ again, the tick was no longer ‘In Beat’ so I was fighting well against the odds  







In Fig-224 you can see the pencil marks I’d been making each time the clock stopped. They are not all in the same (ish) spot but there is certainly a pattern, which is repeated directly opposite.

This leads me to surmise that the outline is now nearer to that shown as a red line in Fig-225 – somewhat exaggerated of course – as opposed to the concentric black outline. I’ll have to do some more work on the other 64T gears before I build the other clocks but for now I’m resigned to waiting for the weather to settle down again before spending more time in trying to get the first clock fully operational.

*3rd Mar*
In the meantime, two things have been keeping me occupied.

1 - When needing to make adjustments to the length of the Pendulum I found that I couldn’t remember from one adjustment to the next which way I was 


making the change so had to work it out from first principles each time! This made me decide to add marks to the Bob showing [F] and to signify whether the adjustment should be Faster or Slower. I’ve made small Maple buttons engraved with the two letters filled black. (Fig-226) These will be set into recesses in the Bob, either side of the Adjusting Nut.

2 - I’ve decided that I could add a ‘Seconds Sub-Dial’ to the basic design. Had I done this originally, it would probably have been at the 12 o’clock position which might have impacted 


upon the design of the Dial but, doing it with hindsight, it will go 50mm lower and be set inside the main Dial. This means that it is slightly more complex in-as-much-as it will need three gears rather than a direct ‘pointer on the end of the Escape Spindle’.

I’ve shown the Gears super-imposed on top of the Dials in Fig-227 and - in the light of the issues I’ve had with respect to the ‘binding’ of the other gears - I’ve changed the tooth profile to provide more clearance. In reality the Gears will all be behind the frame. As silly as it sounds, this ‘complication’ has added 20 components to the total and that’s only counting the ‘dots’ as one!


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## donwatson (4 Mar 2021)

The weather conditions do seem to have an effect. I would opt for building it where it is going to hang and allow all the materials to acclimatise to the conditions. But as we all know they put a case around the grandfather (and other) clocks to stop the wind/draught affecting the pendulum so it looks as if it will be a long road to get the wood conditioned ??


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## Yojevol (4 Mar 2021)

J-G said:


> This means that it is slightly more complex in-as-much-as it will need three gears rather than a direct ‘pointer on the end of the Escape Spindle’.


More gears = more friction = more weight

Is there any particular reason why the last 2.5 paragraphs appear to be struck through? Is this how they appear to you, @donwatson? They appear OK when viewed on the PDF
Brian


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## J-G (4 Mar 2021)

donwatson said:


> The weather conditions do seem to have an effect. I would opt for building it where it is going to hang and allow all the materials to acclimatise to the conditions. But as we all know they put a case around the grandfather (and other) clocks to stop the wind/draught affecting the pendulum so it looks as if it will be a long road to get the wood conditioned ??


I would agree that acclimatisation of materials would be ideal and I do try to keep even raw material as well as part worked stock in an 'inside' environment - my main workshop is directly attached to the house and even my secondary workshop (1m gap between this and the house) is on the same central heating circuit ! 

One of the clocks is was  destined for Essex and another for California so that adds a level of complexity.


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## J-G (4 Mar 2021)

Yojevol said:


> More gears = more friction = more weight


I take your point Brian but hope that with the new (leaner) tooth profile and the fact that there will be a needle roller and a deep groove ball bearing in the train will mitigate the possibility. It will certainly add to the learning curve!



Yojevol said:


> Is there any particular reason why the last 2.5 paragraphs appear to be struck through? Is this how they appear to you, @donwatson? They appear OK when viewed on the PDF
> Brian


Can't explain the strike-out but I've just done an edit and it seems to have sorted it. I certainly didn't select the strike-out intentionally at any time and the icon didn't show 'live' but click [on] and then [off] did the job.


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## donwatson (6 Mar 2021)

I did see the strikeout originally but it has gone now.


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