Portable (bench-top) Workbench

[Dr Al]

Last job of the day was to start work on one of the hand-wheels. After playing around with a few different approaches, I concluded that the best way to mount the hand-wheel on the lathe was with the jaws pressing against the inside of the outer rim.

The pilot hole wasn't concentric with the outer rim (I guess it was drilled relative to the inner hub), so to save my drill bits from having a hard life, I ran an end mill through to true the hole up:

I then drilled the hole out to 12 mm, bored it out to 15.7 mm and put a reamer through it to bring it to 16 mm. The choice of 16 mm was simply because I have a 16 mm reamer and I figured that would give a smooth finish for attaching it to the threaded rod.

I mounted a length of threaded rod in my collet chuck, faced it and turned a portion down to 16 mm.

I could then check that the hand-wheel fitted well:

I then transferred the set-up over to the collet block on the milling vice and tried to figure out how to drill a cross-pin hole! I glued the hand-wheel in place with some Loctite 603 and used a ER16 collet chuck to hold a 3 mm spotting drill and then 3 mm drill bit. I think the roll-pin I was using was supposed to be used with a 3.2 mm drill bit, but I don't have a 4 mm ER16 collet, so 3 mm was the only option. All of my other chucks would have hit the hand-wheel outer rim.

Thankfully I didn't have to open up the hole to 3.2 mm manually: the cross pin went in fairly easily:

With that complete, it felt like it was time for a trial assembly again:

I think the first job for tomorrow will be a bit of a tidy-up: I've made a bit of a mess everywhere!

 

[Dr Al]

I started this morning with a bit of a tidy-up and then sorted out the other two hand-wheels. I didn't bother taking photos of that process as it was exactly the same as the first hand-wheel.

I then fitted a cut-off bit of 50 mm EN1A into the chuck:

I faced the end, chamfered the corners and then spotted the centre hole.

Then it was up through the drill bits as usual, stopping at 25 mm.

I then bored it out to be 30 mm, to fit the bits of tube I'm using in this project.

I moved the tool-post round to an angle and chamfered the ID under power for this one rather than using a deburring tool by hand. No particular reason.

I then flipped the block over, faced it to length and chamfered the OD and ID on the other end as well.

 

[Dr Al]

I then put the block in the milling vice and spot drilled four hole locations.

I then drilled the holes out 5.5 mm and counterbored 8.5 mm.

Here's the finished block. You'll notice that the counterbores are open into the central hole.

My original plan had been to mount four cap screws on the face of the central vice mechanism body (the one for the standard vice). Those cap screws were positioned such that the heads of the cap screws would retain the central tube and stop it from moving up and down. It then occurred to me that if I made it a more rigid connection, the tube that covers the central screw could act as a sort of "stretcher" to increase the rigidity of the structure (the two ends were originally designed to only be connected together by the rails at the top).

This block will be attached to the central tube, probably just with my favourite metal glue, Loctite 603, and will then screw into the vice mechanism joining the two ends together. I could add a cross screw to supplement the glue, but for now I'm going to assume it isn't necessary.

 

[Dr Al]

Next up was the tubes to run in the slotted bushes for the dual-screw vice. The original plan was to have these threaded onto the shafts, but I couldn't face another bit of 2.5 mm pitch thread cutting, so I just took a bit of the tube and skimmed the OD down to 25 mm to fit in the slotted bushes.

I then cut it off with the bandsaw, flipped it over, faced and chamfered and Robert's your father's brother:

My original plan with the holes in the wood for the slotted bushes was to rout them out once the brass bits were glued in place. However, I got impatient and wanted to do some trial fits before things got as permanent as being glued together. The brass bits are a close fit and are prevented from rotating by some dowel pins, so I figured it would be fine.

I fitted a top-bearing flush trim bit in the little router:

After very carefully setting the height so the cutter wouldn't cut brass, I worked steadily away at the holes until they were the same as the brass slot:

Something went slightly awry on the second hole - I think I wobbled a bit and lifted one side of the router up slightly. I don't think it matters though as it doesn't look horrendous and will be on the inside of the jaw.

With all those bits complete I could do another test fit:

Here it is with the top slid into place as well:

That brings us to a bit of a landmark: all the metal-mangling is complete (apart from whatever I decide to do about washers for the dual-screw end) and I can get back to some wood-worrying!

First job is to open up the slots for the vice mechanism bodies (to compensate for moving the shaft hole as I mentioned a while ago) and then I can do some functional tests.

 

[Dr Al]

Well, so much for "no more metalwork"... but more on that later.

This afternoon I started by working out how much extra space was needed for the vice mechanism. To do this, I fitted the vice mechanism to the fixed jaw and slid the foot up as far as it would go:

I could then measure how much the foot needed to move to get to the right place and therefore how much material to take away. Then I could mark it up and saw down the sides:

Chopping the material away was very quick as I was cutting along the grain:

Finally, I pared the bottom down to make it a bit neater (although it'll be hidden under the vice mechanism so it's not too important how it looks):

Having screwed the vice mechanisms to the fixed jaws, it seemed a good point to try one out with all the metal bushes / bearings etc in place. That's where I found that the vice mechanism didn't work. Lots and lots of profanity ensued.

When I made the original vice mechanism prototype over Christmas, I did lots of testing to make sure it worked consistently and could be tightened very tight. When I modified the design to make it fit into a smaller space, I just checked it engaged and disengaged but didn't do any further testing. That was a mistake! What seemed to be happening was the geometry of the tube, the hinge bar location and the nut were such that as it tightened, the tube lifted off the threaded rod, which allowed the nut to drop away from the threaded rod.

After lots of messing around with various random scraps of material I had lying around, I worked out that all that was needed was something that would stop the tube from lifting when it was at the angle it sits when locking. I put one of the vice mechanisms back in the milling vice and drilled another 6 mm hole through both sides of the mechanism. I then turned a simple tube, 15 mm OD, 6 mm ID to sit on the new shaft and act as a stop.

The reason I went with a 6 mm shaft with a separate part sitting on it was it gave me room to tweak the diameter if it didn't work. I'm glad I did as for some reason I can't quite work out, one of the mechanisms needed a 16 mm tube instead of a 15 mm one. I presume it must be something to do with the location of the hinge bar (which is arbitrary) as I'm fairly sure I drilled the hole in the right place!

With this modification, the vice is rock-solid and clamps bits of wood extremely robustly. Phew!

Anyway, with all the vice mechanisms modified and working well, I put the whole lot back together and clamped a random bit of wood in the dual-screw vice:

and cut the end off!

That was amazingly satisfying for such a simple job!

This isn't really the purpose of the dual-screw vice (I'd usually use the standard vice for this sort of cut), but I'd assembled it with that end facing out so I figured it would do.

If you look closely at those last two pictures, you'll notice that I've clamped one of the feet down to the workbench. It's a sign of the heft and hence stability of this thing that it didn't wobble at all, even though the end I was using wasn't attached (apart from via the screw threads going loosely through the holes in the rails for the other vice) to the bit that was clamped down.

I'm a much happier bunny now than I was when I realised it wasn't clamping properly!

 

[Dr Al]

What with it being a work day again I didn't get much time today, but I did manage a little.

I took everything apart again and ran round a few of the edges (outside of the moving jaws and the edges of the feet) with a 6 mm Arris bit in my small router.

I then got some 120 grit sandpaper and gave everything a once over. For some strange reason, I elected to do this by hand rather than using any power tools. I don't know what came over me!

I'd been debating what to do about the feet as I wanted to round over the corners of the feet but it would look a bit odd if it blended into the hard edge of the fixed jaw. Without the rounded edge, I needed to do some adjustment to either the fixed jaw or the feet to either make them line up perfectly or make them look deliberately not aligned.

After playing around in the CAD model, I took the plunge and went round all the outside edges of the feet; hopefully it'll look okay when assembled having a rounded edge on a join.

You can (hopefully) see the where the rounded edge of the foot meets the square edge of the fixed jaw in the latest version of the CAD model:

Here's what one of the feet looks like after shaping and sanding to 120 grit. I'm definitely not going for perfection here: it is first and foremost a tool rather than something that has to look pretty.

While everything was apart, I took some photos of all the bits I've made so far:

 

[Orraloon]

I started watching this thread as ok another benchtop bench so worth a watch but its become the dog's thingies of benchtop benches. A woodworking thread where the metalwork is the star. Great to watch.
Regards
John

 

[Dr Al]

I started watching this thread as ok another benchtop bench so worth a watch but its become the dog's thingies of benchtop benches. A woodworking thread where the metalwork is the star. Great to watch.
Regards
John

Thanks John

 

[Dr Al]

I wasn't expecting to have any time in the workshop today, but I got the food shopping done fairly early and couldn't resist spending an hour or so in the workshop.

The vice mechanism bodies for the dual-screw vice interfere with the beech rails that run along the sides underneath the top. My original plan was to cut away a section of the rail to allow for the vice mechanism bodies, but I decided to cut away the body instead. I put two of the vice mechanism bodies in the milling vice (one at a time) and hogged out a 12 mm × 4 mm section from the corner:

I then put each of the three vice mechanism bodies in the vice, centre drilled 3 mm and (very carefully) drilled 2.5 mm:

I then put an M3 tap in the chuck and turned it by hand to tap the holes. I generally avoid tapped holes as small as M3 given the choice, but I wanted a size that had a cap screw head diameter smaller than the 6 mm thickness of the plate.

Here you can see the tapped holes in all the bodies:

The reason for these holes is that the top surface of the workbench will have a number of dog holes drilled in it. Inevitably lots of sawdust etc is going to fall through the holes and I'd rather keep it out of the workings of the mechanism if possible (the mechanisms at the dual-screw vice end have to be removed from the workbench in order to get to them for cleaning or whatever).

To that end, I got some bits of 1.3 mm aluminium sheet out and marked the plastic-coated side:

I then used a Stanley knife to score along the marked lines. I find 10 strokes of the Stanley knife on each side of the sheet and then a little bit of bending back and forth results in a very clean and straight cut:

The resulting pieces:

I then marked the sheets out for the holes and centre punched fairly deeply:

Each sheet was then clamped down to my home-made fixture plate (drilling sheet metal is scary!) and drilled out 3.5 mm. The centre punch marks were deep enough that I didn't need to use a spotting drill first:

This is what the bodies look like with their lids attached:

I've left the plastic sheet on the aluminium for now; I'll peel it off when I'm closer to finishing everything.

 

[Dr Al]

I'm sure I said something about having done all the metalwork a while ago.

One of the jobs on my list was to decide what to do about the washers for the dual screw vice. The latest version of the model has each screw having a pair of very custom washers designed to cope with angular misalignment:

I've had some ideas about how I might make those, but there's no doubt they'll take a lot of time and for the amount that I'll be clamping tapered stuff in the workbench I'm not convinced it's worth the effort, so for now I've decided to go with something simpler.

I put the fixed steady back in the lathe (thankfully it was still set up for 50 mm stock, so this was quick and easy) and made these simple washers (I didn't bother with in-progress photos as they would be very similar to a lot of previous photos):

Here's where they go:

I'd also be pondering more about the block I made to fix the central tube to the central vice mechanism and make it act as a stretcher. You may remember my earlier change of plan when I went from cap screw heads supporting the tube to having a block that clamps the tube to the vice mechanism. That resulted in some nasty cap screw locations and I didn't like that very much, so this evening I made a new one out of 60 mm EN1A. You can see the new one here along with the old one and the vice mechanism to which it attaches: I've drilled and tapped two new M5 holes for this new block to screw to.

Here it is fitted:

While I was in metalworking mode, I faced all the jam bars to length on the lathe and cleaned them up a little with some wet-and-dry paper as some were showing signs of rust already:

Just out of curiosity, I thought I'd try out the bottle of cold blue I bought a few years ago and still hadn't used:

I've already had to sand a bit of rust off the tops of the vice mechanism bodies as well, so I want to treat them in some way (and maybe some of the round steel parts) before I assemble them into the vice. I haven't decided what I'll do yet though.

 

[TheTiddles]

For up to 7-degrees (I think) you can use spherical seating washers, readily available
Aidan

 

[Dr Al]

I spent a bit more time sorting out the steel parts in an attempt to make them resilient to rust today. I experimented with a few different bluing methods, including heat & various types of oil, but I concluded that I preferred the look of the cold blued parts, so I decided to do that to the rest of the steel bits (apart from the tubes for the vice rails as they're too big to do easily so I think I'll just rely on grease or oil or something like that for them).

Here are all the remaining parts (apart from the vice bodies, which I cleaned up with a non-woven wheel on the angle grinder and then forgot to take a photo):

The bodies were a bit of a pain to blue: the instructions on the bottle suggest they should be submerged, but that would requite a LOT of cold blue! I just kept turning them and brushing the solution onto the bodies.

Here are all the parts having been blued, rinsed, oiled, left for an hour and then wiped:

The finish on the bits that were fully submerged came out quite well:

With that done, I figured it was time to start making stuff permanent (scary moment)! I started by gluing the magnets into the half-tubes. As it's always a good idea to make a major change at the point of gluing and without testing , I decided to glue two magnets into each tube instead of just one. Hopefully that will increase the strength (not that it needs it really). I started by cleaning the bore carefully and then putting some Araldite around the rim:

I then pushed the pair of magnets into place and daubed over the inside and outside of the magnet. An offcut of threaded rod was used to wipe the excess from the inside and I carefully scraped most of the excess of the outside with a plastic spatula thing.

With that done, I thought I'd carry on with the gluing and fix some of the other bits together. Here are the bits that I glued in today. I've still got the hinge bars to glue in, but I'll do that tomorrow once the Araldite has set.

First I glued the bushes that run in the slots in the dual-screw vice into their new washers:

Then I glued all six jam bars into the bodies. That's all the gluing done for the day.

While I was waiting for the cold blue to do its magic, I also marked up the bench top for the dog holes. I'll drill them in the next day or two probably.

I've got next week booked off work, so it feels like I'm on the home straight now.

 

[Dr Al]

Today I acquired...

Some spherical seating washers. I decided to take good advice and just buy these components. Until I can get round to making spherical turning attachment for the lathe, this seemed like the best idea. According to the dimensions on the website I bought them from, the convex parts should have been a reasonable close but loose fit on the bushes I made and the concave ones should have a reasonable amount of clearance for angular adjustment. The latter was true, but the convex ones don't quite fit. I'll have to mount them on the lathe and skim a tenth of a millimetre or so off the bore.

More on that later.

As far as actual work on the bench goes, I started today by drilling out the dog holes for the top.

I then put a chamfer bit in my small router and chamfered all the holes slightly.

There had been a bit of tear out on the bottom of the holes (despite having a backing board: I hadn't clamped the top to the backing board so I think they separated as the drill bit went through). To hide some (but not all) of the tear out (which will never be seen anyway as it's on the underside of the top) I did the chamfer a bit deeper on the bottom.

I then put the workbench together with clamps so I could mark out the hole locations:

With the top in place, six of the dog holes are over part of the feet:

I marked the hole locations out by using my 20 mm Forstner bit and pressing down by hand. I then followed that up with an awl to make the mark more obvious.

My plan had been to drill these holes out 22 mm to allow for some movement in the top (which will be attached with buttons). The holes in the foot will be there to allow clearance for longer dogs to be inserted, but they won't be providing precise location or anything, so 22 mm seemed a good size.

Unfortunately, when I came to drill the holes out, I came across a bit of a problem. I was sure I had a 22 mm Forstner bit, but it seems I'm wrong! The outer holes are also only 11 mm from the edge of the wood so that size Forstner bit is probably not ideal. I'm going to ponder on this for a bit. I could just cut the end of that bit of the foot off, but I quite like the fact that the edge of the foot goes up to the rail. I could also cut out more selectively (cut a U-shaped bit out of the edge). To be determined...

 

[Dr Al]

Putting the decision about how to relieve the holes to one side for a bit, I decided to get on with the buttons for attaching the table top. I started by setting the table saw up at an appropriate height and offset for one side of the groove:

Two passes on each piece later and I have grooves all the way round so I can put the buttons anywhere I want:

I used an offcut from the scrap bin (it had several nasty knots in it, so wouldn't be much use for anything else) and used the table saw to cut the button outline:

I then cut two strips away from the block and did a test fit:

The two strips of buttons were put in the vice and marked up. This is going to produce WAY more buttons than I need, but it doesn't take much extra time to make them en masse and I can pick the best looking ones at the end:

The holes were drilled and countersunk (a bit raggedly):

I then used my home-made bench hook thing to separate the buttons. The stop makes this very quick to do:

I now have a big pile of buttons!

 

[Dr Al]

A very nice man sent me a bundle of strips of American Black Walnut.

I ripped three of these to size (two because I need them and one spare) and then planed them such that they were all exactly the same size. The actual size doesn't matter, but they need to match:

I then proceeded to play around with lots of ways of making a simple finger joint and concluded that it's quite hard to get it looking good! In the end I settled on using a biscuit cutting router bit:

I then extended the cut down with my dovetail saw and chiselled across the bottom to complete the joint.

I also took a long cut out on one of the pieces. I did this by cutting as far as I could safely manage with the table saw and then finishing off with a hand saw:

 

[Dr Al]

With a small lump in my throat, I set my cross-cut sled up to take a big chunk out of the fixed jaw of the dual-screw vice:

Having cut round two sides, using the little "kerfmaker" knock-off to get the right width, I used my baby router plane (one day I'll find an affordable big router plane for sale!) to clean up the bottom of the groove:

This little router plane doesn't have any built in height adjustment, so I set it on a couple of feeler gauge pieces and dropped it into the groove:

The slot looks much better after routing:

I could then check the fit:

This little insert (which won't be glued into place so it can be removed when not in use) gives a right-angle reference for lining up dovetails, something like this:

It needs a fair bit of tidying up before it's complete, but hopefully you get the idea. In practice I'd probably put something under the tail board (and lift the pin board up accordingly) to reduce the risk of the knife cutting into the moving jaw of the vice.

 

[Dr Al]

This afternoon I started with a very quick job: drilling a hole in the end of the fixed jaw for the standard vice. The aim of this hole is to be a loose fit for an off-the-shelf dowel. I don't want to have to modify the dowel as I expect to replace it fairly often. It'll act as a sacrificial "saw catcher" when I'm cutting through stock close to the jaws. If I overshoot at the end of the cut, the saw will drop onto the dowel rather than onto the bench (or whatever) underneath.

I did some tests with a few different drill bits and found I didn't have one that was tight enough to hold the dowel without being too tight. 10 mm is too tight, 10.5 mm is far too loose. I dug around in my "antediluvian tools" drawer and pulled out a set of drill bits I'd inherited from my father-in-law with a 13/32" (10.32 mm) drill bit, but again that was too loose. In the end I settled for drilling 10.32 mm to a reasonable depth and then drilling a little further 10 mm. The dowel slips most of the way in easily and then sits firmly if pushed the last couple of millimetres. As it's only gripped at the last couple of millimetres, it's easy to pull back out again.

Next I fitted a stop block onto my router table (just a bit of wood clamped to the fence):

Then, taking a couple of millimetres off at a time, I cut a groove in one of the fixed jaws.

The result:

I then marked out and chiselled out an extra bit. This is (deliberately) not as deep as the routed groove.

With the foot in place, the result is a rectangular hole that's a loose fit for the dovetail guide I showed in the last post. The stepped bit in the top is a slightly tight fit in the section I chiselled out. When the dovetail guide isn't being used, it'll get slid into its home and will hopefully stay there but be easy enough to remove when required.

 

[Dr Al]

Next job was (scary) to start to glue the first few bits together. Before doing that, I thought I'd get some photos of everything pre-gluing.

 

[Dr Al]

The first bits to get glued together are the feet to the fixed jaws. The dual-screw vice end fixed jaw is aligned with lots of dowels and a bit of the tube that I've used for vice rails. The standard vice end is aligned with the two vice rail bushes. I got everything set up and mixed up some more Araldite (as it has a much longer open time than the wood glue).

I then glued and banged in the dowels and pushed the tube into place (without glue). I didn't take any more photos for a while after this one as everything gets a bit frantic when I'm gluing stuff together!

Finally (for this one) I pushed everything together, clamped it, wiped all (or at least as much as possible of) the squeezed-out glue off and then pulled the tube back out again (I'll glue that in later). The other end was much simpler, but before starting on the wood glue, I put some of the mixed-up epoxy on the inside of the flange where the vice rails (and the screw bush while I was at it) sit:

Since I was on a bit of an Araldite roll, I also epoxied the bearing block into the moving jaw for the standard vice and the two slotted bushes into the moving jaw for the dual-screw vice. The flanges were definitely a good thing on the other brass bits - there was a lot of messy squeezed-out Araldite at the bottom of the hole for the slotted bushes. I cleaned up as much as I could, but I'll have to do more when the epoxy has cured.

Here's everything clamped as it is now:

I also glued the hinge bars into place. To do this, I fitted each one dry, then slid it out one way and put a very small drop of Loctite 603 on the end, then slid it the other way and repeated that. I'm hoping that this results in the hinge bar being held in place but the nut still pivoting on the hinge bar. If it jams up I can always get it undone again with acetone or heat.

Finally I glued the dovetail guide up by clamping it to a small welding square. This will need more work to clean it up a bit, but I'll do that once the glue has dried.

That brings us to the end of the day's work. It's been a major step today as it's the first time I really can't go backwards and change something (without going shopping for more beech and basically starting again!). Hopefully when I go out tomorrow morning I won't find anything drastically wrong!

 

[TheTiddles]

Spherical seating washers aren’t precision components unfortunately, they’re mostly used to bolt I-beams together, which at least makes them cheap