WIP - Cogitation - Designed by Clayton Boyer

[Ian down london way]

And so it starts (November 2012).

This is the page on Clayton Boyer's site, of what I'm attempting to make.
http://www.lisaboyer.com/Claytonsite/co ... npage1.htm

I'll be letting Clayton know about this thread, so he can keep an eye on me

So, first, a picture, taken from the plans, of the overall project.

.

Having read (well, at least some of) the instructions, I'm starting with constructing the frame, which sits at the back. Its barely visible in the picture above, as its at the back.

The plans for the frame have to be assembled from 6 sheets of A4 (once copied) paper. Here it is assembled. The plans include a checking plate to ensure that the centers of cogs which are supposed to mesh, are the right separation (when they are on different sheets of paper).

I want to use a dark wood for the frame, to act as a contrast to the wheels / cogs, many of which are likely to be beech ply.
I've the remains of a fire place mantle given to me by a friend. Its a dark hard wood, very old and stable, so I shall see how that behaves first. The frame is made of 3/4 inch (sorry - they are American plans!) thick solid wood. I obviously want the grain to run along the three parts of the fame, so it will have to be constructed from at least 4 pieces.

So, first job, create a decent amount of 3/4 inch stock from the mantle.

Time to make some noise

 

[Max Power]

Sounds very interesting. Don't worry about quoting imperial sizes , we did invent the system over here after all :lol:

 

[xy mosian]

Great. A good thread to follow for at least part of the winter months.
xy

 

[Ian down london way]

So, to create the 3/4 inch dark hard wood for the back frame, I used my thicknesser (a noisy dewalt 733).
So, I have a 1.4m long, 140mm wide plank. Quite nice looking, but very narrow (only two of the bits are that narrow).

However, trying to fit the 4 or 5 curved sections needed for the back plate on such a narrow plank was tricky. Although i made templates of the pieces I needed, and then templates of the plank, it was too difficult.

In the end, I decided to create a single slab, as I could then pack the templates of what I needed much better. Pondered how to joint them, but decided on a simple edge to edge white glue in the end. Its not structural.
I had made my own clamps years ago, using some Veritas panel clamps, which I find work well. I remembered to apply plenty of top-to-bottom pressure before tightening the clamps to keep the planks flat. And this time, I remembered to protect the clamp bars from the white glue with some paper (I expect grease proof would have been better, but what the heck.

Slab looking pretty good the next day, but need to tidy them up. Cabinet scraper seems the right tool, but of course they are blunt. They do seem to loose there bur during storage - I wonder if that's actually possible. Humm.

After a quick search on the internet (I do like the luxury of a computer in the workshop, although I think the computer does not appreciate the dust), I managed to re-bur them, using a diamond file thingy, and found a Veritas bur-er (?).

I should say this is not an advertisement for Veritas. I think that may be all the products of theirs that I have. But getting the bur right on a cabinet scrapper is tricky, and I do find that two passes with the bur-er works really well (then rotate it, work the other way, and you have a bur on each side).

Dang - you can see the third Veritas tool I have, a gadget to hold scrapers. I love that, as it allows me to work without creating flat finger tips.

Next job, lay out the pieces, and remember to leave enough extra on the ones that are going to be jointed. I will do a simple lap joint, which will provide plenty of glue surface.

 

[Joe Shmoe]

this is great, awesome project and great wip. thanks very much, watching with great interest.

 

[Ian down london way]

From Slab to frame - in a week

Well, I said it was a hobby so don't expect progress to be too quick.

Having posted my first two entries I've taken the bold (to me) step of emailing the designer in Hawaii and my daughter, who can both keep an eye on this blob - Hi Tasha ! (and if she does not email me back, I know she'd bluffing if she says she'd looked at this !!!).

So, having studied (haha) the instructions, I chose to joint up the frame by rough cutting the pieces, then using a half blind joint joint it all up and only then, when its strong and stable, to lay on top the accurate plans, for the accurate drilling and cutting. Its really the separation of the holes that are important, not the wood itself.

So, a picture paints a thousand words - thank goodness.

First, the rough layout. I'm not too worried about where the slab joints are, although avoiding where the holes go (hummm, more on that later).

Now, bandsaw out the pieces, but only roughly. I want plenty of spare space around each. Its way more difficult to joint curved pieces accurately. Much easier to cut it after its jointed, but then you need some slack on the size of wood.

Now, the blind joints. Now that is a challenge. Its a very hard old wood, and blind joints with a chisel are seriously hard work. I decided to try using a solid carbide router bit, mounted in a pillar drill. Its cut a cutting surface on the end, so whilst I'm not intending to plunge at all, its good for not burning the wood.
I take off only a little at a time, about 2mm, but it seems to work pretty well.

Of course this leaves corners which are round. Now long time ago I learnt that you really don't need to square up the holes, just round off the tenons, so much easier.
So, now all dry jointed.

I decided on helping the gluing process with some screws. (Shhhh - only you guys will know!)
So each tenon has a couple of screws as well as normal white glue.

I used a random orbit sander, plus a cabinet scrapper to flatten it all off.

And here is the end result, after I've used some more white glue in the gaps, and rubbed in a combination of cabinet scrapings and saw dust.

Now to lay the accurate plans on it. As for all of these bits of paper, I've been using a spray repositionable adhesive. Most recent purchase had a spare nozzle in the lid, which is great (although I do always turn the can upside down and vent till only propellent comes out, to clear out the nozzle anyway).

And the accurate cut - this was done using my Hegner (and a new large tooth blade). Also had bought a decent set of imperial drill bits. Of course the most important thing is the accurate placement of the holes. I drilled a small pilot hole (1/16th inch) for each of the holes - most of which are 1/4 inch. it helps to settle the larger bit more accuratly. I'm aiming for better than 1/2mm accuracy for the hole positions.
And there lay my first potential major problem, I hadn't thought, when I put the screws in, where the holes needed to be drilled. Very fortunately, none of the holes hit any screws, although one did go through a joint gap. However, its only holding a stopped, rather than anything too structural, so I think it will be fine (and if not, well, we shall see).

So, I'm quite pleased with the end result. I'm not sure yet whether to chamfer the front edges, or round them, or leave them sharp. Best to decide late in the context of how they look with the rest of the structure overlaid.

Of course, the rear is not quite so pretty. (don't tell anyone!).

End of another week.
So, too many pictures? feed back would be appreciated.

 

[Chems]

Very fortunately, none of the holes hit any screws, although one did go through a joint gap. However, its only holding a stopped, rather than anything too structural, so I think it will be fine (and if not, well, we shall see).

Worst case couldn't you glue in a dowel and re-drill the hole?

Of course, the rear is not quite so pretty. (don't tell anyone!).

Props to you for showing the Shrek side. I think you were right to add some extra form of stability on those joints. Although technically a half lap joint they can't be large enough to support something that looks quite large.

Keep the pics coming, there are an awful lot of lurkers on this here forum who don't contribute any but I for one am enjoying the build having spotted it this evening.

PS. The more pics the better!

 

[AndyT]

Yes, keep the pictures coming even if there are gaps between sessions and not as many comments as you would expect. I think that some of the most worthwhile threads on here are where you can watch how someone solves the succession of little challenges that come up in a project like this - as you are doing.

 

[trsleigh]

From Slab to frame - in a week

And the accurate cut - this was done using my Hegner (and a new large tooth blade).
So, too many pictures? feed back would be appreciated.

Ian, great pics, never too many.

Now a question re scroll saws. I've got the Axminster AWFS16 ( bottom of range ) and I can't say using it is particularly relaxing to use. A quick Google seems to imply that Hegner are the dog's b******s when it comes to scroll saws. Have you ever used any other saws you can compare your Hegner to? Is it much smoother, less vibration, in your opinion is it £300 better than a cheap n cheerful model?

Anyway, keep it coming.
Toby

 

[JakeS]

Yes, keep the pictures coming even if there are gaps between sessions and not as many comments as you would expect. I think that some of the most worthwhile threads on here are where you can watch how someone solves the succession of little challenges that come up in a project like this - as you are doing.

Seconded! I find the project fascinating, and I've read the posts so far with interest - I just don't have anything constructive to add!

 

[Ian down london way]

Now a question re scroll saws. I've got the Axminster AWFS16 ( bottom of range ) and I can't say using it is particularly relaxing to use. A quick Google seems to imply that Hegner are the dog's b******s when it comes to scroll saws. Have you ever used any other saws you can compare your Hegner to? Is it much smoother, less vibration, in your opinion is it £300 better than a cheap n cheerful model?

Anyway, keep it coming.
Toby

I'm afraid I can't help with that. For many years I'd buy cheap tools, and then eventually go through an upgrade. However, having used a Henger on a course in Wales, I went straight for that as my first, so I can't compare.

 

[bugbear]

A quick Google seems to imply that Hegner are the dog's b******s when it comes to scroll saws.

I think they're the Le Creuset of the scroll saw world. Not the absolute top, but very near it, and for a very long time.

BugBear

 

[Ian down london way]

Have you ever used any other saws you can compare your Hegner to? Is it much smoother, less vibration, in your opinion is it £300 better than a cheap n cheerful model?

Anyway, keep it coming.
Toby

I'm afraid I can't help with that. For many years I'd buy cheap tools, and then eventually go through an upgrade. However, having used a Henger on a course in Wales, I went straight for that as my first, so I can't compare.

One thing I wood add (haha), is that I did attach the hegner to the table, but placed it on a foam mouse mat rather than directly on the chipboard bench I use for it. I found that the noise was much reduced, even thought its held down by a couple of bolts (well, bolt threads with handles attached, as I don't always have it out). The bolts (2 of) hold it in place, but the foam reduces the transmitted vibration.

 

[trsleigh]

One thing I wood add (haha), is that I did attach the hegner to the table, but placed it on a foam mouse mat rather than directly on the chipboard bench I use for it. I found that the noise was much reduced, even thought its held down by a couple of bolts (well, bolt threads with handles attached, as I don't always have it out). The bolts (2 of) hold it in place, but the foam reduces the transmitted vibration.

Thanks for the tip, I'll just persevere.

 

[Ian down london way]

Woodwork? What woodwork!

Well, its time to make the arbours on which the cogs will all spin.

I bought them all from CJW steam, on the web. They are a model engineering place, seem to specialise in train stuff. However they have a full range of imperial and metric, brass and steal, good prices, good postage, and very fast. Used them a few times and no regrets at all.

However, one pic I left out last time, how I sanded the curves. I used a spindle sander - works a treat.

I thought you guys may be interested in the dust extraction system I use.
I have a primary extractor, which I plumbed in using a combination of rigid ducts (clear - love to see the stuff wosh though!) and flexible, to fit.

I also have an overhead suspended air-born dust remover.

But my most recent toy really adds to the effectivess of the dust extractor, especially the main one. I never invested in the electrically connected blast gates, so I have to walk over to the main extractor to switch it on, then use the tool then walk back.
Hmmm. I must admit, it wasn't used as much as it should.
Then I saw a remove control device in B&Q. I was a bit concerned it might burn out from the inductive load, but in the interests of helping other woodworkers out, I thought I'd give it a go.
This is the one. Comes with 3 (I think) things you plug into the wall, and one controller. which I hand around my neck.
This is it. It works a treat. I control the overhead and the main extractor. I still have to manipulate at least one blast gate, but that's normally the one by the tool I'm using. Only the thicknesser has a separate thick pipe.

Anyway. The brass rods and tubes all need to be cleaned, and cut to length. Quite a lot of them.
I use metal polish from Halfords to clean them first - very expensive, but you don't need much. I mount them in a slow-ish running pillar drill and use paper towel to clean them down. The coating comes off very black. I hope they won't tarnsh now the coating is removed, but they shine afterwards

I use a dremel to cut them, much neater than a saw. Then I use a grinder to get them neat and the correct length.

The end result is this - yea - that is quite a few hours of work, especially the tubes, which need to be clean / polished inside too, so they slide over the brass rod.

So, Lastly, I've now mounted the frame on a board, so I can start assembling the beast, in the manner the plan suggests.

Next stop - Cog-land
(and the Hegner earns its keep !)

 

[paul-c]

hi ian
great wip pics.
i look forward to the future work.
thanks for posting
cheers
paul-c

 

[Ian down london way]

First Cogs - the Drivers

And so the Hegner starts to earn its keep.

The weights which drive this contraption hang down on cords in order to turn the 'drive cog'. This is a substantial first cog which has to take the highest levels of stress. The plans span two sheets of paper, so its worth ensuring it all lines up by using a large compass, to make sure the teeth still form a circle.

Therefore this one, of all the cogs, really needs to be made out of ply, in order for all the teeth to be strong enough. It needs to be 1/4 inch thick, but I decided to make it from two layers of 3.8mm ply, (rotated 60 degrees) and then thicknessed (is that a verb?) off the back only - keeping the front nice.

First thing, is to accurately drill the centre hole. If that goes horribly wrong, then at least I've not invested lots of teeth cutting time before starting again. In this case, I need a 9/32nd hole (odd size reasoning in a moment). Having rough cut a circle, leaving some spare wood around the outside, I cut one side of the teeth only, all the way around. The spare wood give me some room to steer the blade to start the cut more accurately then had I made an accurate circle first.

Then I cut the opposite side of the teeth, and also the base of the cut, popping the waste wood out. This leaves sharp teeth all the way around.

To make sure the teeth ends are circular on the cog, I mount the cog as it will be mounted. This involves a 1/4 shaft, and a 9/32 brass tube which will later be attached within the cog centre hole. The thickness of the tubing is such that a 9/32 tube can smoothly rotate on a 1/4 (8/32) rod. So, I mount the 1/4 rod on some MDF and present that to my rotated belt sander (I keep it that orientation permanently). and turning the cog against the belt sander can ensure that all the teeth are a good 'height'. I hope that makes sense.

After then cutting out the insides of the cog, and smoothing off using the bobbin sander, and a little bit of finishing with random orbital sander, and by hand the results is this:

I need a cap to keep the 9/32 brass tube (and hence the drive cog) in place. I decided to use off cuts from the frame for the caps, ties the front to the rear and a nice contrast against the birch ply. I'm not great at turning, and this is very small. However I did find that if I drill a 1/4 hole in the off-cut, and then super-glue it onto a short length of 1/4in rod, it holds ok. I then mount the rod in a drill chuck, and turn it that way. When finished a sharp tap can dislodge the cap off the rod - job done.

And here is one I made later - the item needs two drive cogs. So, two down, and LOADS to go.
(And hey, if it doesn't work, at least I'll have something nice to look at - I do like the contrast of the dark and light wood - even if one is ply)

Next step, is a sort of pulley arrangement which is glued to the back of the drive cogs (through which the supports of the weights go) and the escapement (duplicated top and bottom).

 

[xy mosian]

Great stuff, keep the updates coming please. I admire the concentrated patience you must have to cut those gears.
xy

 

[Ian down london way]

Drive Drum (behind the drive cogs)

AKA The First big "Oh Dear"

(Please see bold edit I've added at the end of this entry)
First job, is a decorative front to the drive cogs. Easy enough, except it's supposed to be 1/16th inch ply. Hum. Not available (would have to be incredibly thin layers. Could make it from three layers of veneer, but that would be really expensive). I decide to sand down some ply, which takes forever, and isn't very flat. Successful technique is to slip in a raised bed on the thicknesser, and then use that. Although its a heavyweight machine (see earlier posting), as long as its only skimming, it can take down to that thickness without destroying too many pieces in the process Our course, it's helped by only one face needs to look good.

After using a small jungle of clamps:

Job done - looks fine.

Times two, and onto the next stage.

Behind those nice drive cogs needs to be mounted a drum, through which is attached the line which holds the weight - 4 in all, 2 per drum.

They are made by sandwiching layers of wood together, but with some layers at 1/16 inch, making them out of the ply that is recommended, is tricky. It's not helped by the UK ply sizes not aligning to USA ply sizes (which are all about 1/16, 1/8, 3/16, 1/4).

However the pieces are small, so I try building up the drum from over thick layers, and then sanding them down to the required thickness. Worse case scenario, if I go to far, is to sand it right off and glue a new piece on. Not hugely easy to sand down parallel with previous layer, but by using a 1/8in hole down the middle, and by holding the item using a 1/8th in steel rod, I can both hold it more safely and with more accuracy against the belt / disc sander.

So, all is well with the world.

Glue these to the back of the drive wheel (which already has the right size hole, hence I could show it on the shafts, as its got one of the 9/32 brass tubes push fitted inside.

View attachment 603

Now just extend the 9/32 hole using the drive wheel as a guide - using my nice relatively new floor standing pillar drill.

Looks very nice I think.

Speaking of pillar drills, I bought this particular model as it has an adjustable head, which give a really deep throat. Very handy at times. The head can also rotate, but I've not seen the point of that, better to keep everything aligned, and use adjustable tables.

I also use this milling table quite a lot. Most often, it holds a surface, but sometimes I will clamp wood directly into it. Its not machining quality, but for woodwork, its very handy.

And this is where the first major problem occurs. Whilst the drive cog and drum look nice enough, when they spin, they wobble. So much, that it looks doubtful that I will be able to engage the escapement cog robustly. Oh C**P. :evil:

After some pondering, its clear that the hole through the drive wheel/drum combo isn't perpendicular to the drive wheel itself. After more pondering, this simple test, first applied to the top of the adjustable table, then to the pillar drill table, makes it clear that I've a pillar drill set up problem! The square is touching the drill bit at the top, but there is a ~ 2mm gap at the bottom. #-o

After much fussing around with the table, I eventually track the problem down to the drill head ! This fancy adjustable drill, has rotated a little at the top! Well, it may have a nice movement to it, but the locking handle which avoids the rotation of the head needed some more work. Well, I know now to keep an eye on that.

Grumpy for a day or so, till I face up to correcting the problem.

And so, how to fix it.
Well, first thing, drill out the 9/32 hold, to 9.5mm as that is the size of some metric dowel/rod that I have, and I plug the hole. Then I drill the 9/32 hold again, from the front, and out the rear. This is the result. You can see the old hole by the darker dowel wood. So it was out by about 1mm, over the 30 or so depth. A huge amount. I'm really annoyed I'd not seen that earlier. It does mean that the rods out of the frame won't be quite perpendicular either, but I've thought about it, and I don't think that's a problem. But I shall keep that in mind if things aren't quite right later. (what else had I drilled recently....).

Next stop - the escapement and the cog that engages with the drive cog.

I'd like to make a suggestion, in order to motivate me to keep posting. There is a "good" icon (thumbs up) at the bottom of posts. Even if you have nothing particular to say, that warrents a post, if you have an interest in this thread and would like to see future entries, can you use the "good" button. I can see how many people select it, and so differentiate between the number of views - which could be people with no interest in it, but perhaps the title caught their eye - and those who would like to see the next entry. It will help considerably to motivate me to spend the time photographing, editing the pictures and making the entry itself. Thanks very much.

 

[gregmcateer]

Looks bloody good to me - I'm going to keep watchin in interest and awe.