Portable (bench-top) Workbench

[RichieG]

Has been great following this. It's a work of art! Thanks for the comprehensive updates

 

[Dr Al]

The first job of the day was to take a deep breath and have a go at fitting the leather. I had no spare leather and have never worked with this material (apart from for the test jaws) before, so I was a bit nervous about this. I started by getting a bit of 9 mm plywood (that came as part of the packaging for a very well-protected #7 plane I recently acquired) and drilling three holes in it. These didn't have to be super accurate, so I just marked them out and drilled them on the drill press. The outer two holes were drilled with a 30 mm Forstner bit; the inner hole was cut with a 50.8 mm (2") hole saw as I'd made the punch 50.8 mm to give clearance around the 50 mm threaded bush.

You can see in the photo that I also put masking tape all the way around the rim of the jaws to stop contact adhesive getting on the oiled faces. Next I clamped one end of the longer piece of leather to the plywood and stretched it by hand before clamping the other end. I could have done with more hands for this, but I got there in the end!

I could then use three of my home-made punches to make the holes. For each hole I positioned the hole location over one of the bench legs (scaffolding poles), put the punch in place and then hit it repeatedly with a hammer.

It seemed to work well, giving clean cuts. There was obviously something on the old cutting mat I used as a base as it has stained the leather slightly near one of the jaws. Thankfully this is the contact adhesive side, so it's not a problem, but it gave me good warning to use some extra protection when I do the other jaw, which will be punched with the visible side on the cutting mat.

I took the offcuts of leather and put masking tape on them and then cut round a slightly larger circle by eye with a craft knife:

I could then use these circles to mask the area immediately around the holes and make sure no contact adhesive got through and on to the visible face. I also put masking tape along the edge of the leather (which is slightly wider than the jaw so there's space for this outside the adhesive area). Finally, I put some lithium grease on the threaded insert, pushed it into place and then masked over the top of that as well. The contact adhesive could then be spread over both faces:

After leaving it for about 10 minutes to get tacky, I flipped the leather-clad plywood over and slide it over the rails of the jaw. I then got a bit carried away clamping it together:

After 5 minutes or so to be sure it had set (the packet says it's an instant bond requiring no clamping, but I figured it couldn't hurt to err on the side of caution), I took the clamps off and (with some paper between the cutting mat and the leather), trimmed all the way round the jaw:

That worked surprisingly well:

 

[Dr Al]

Next up was the dual-screw jaw. For this one, I didn't punch the holes first, so laying everything out was relatively simple. The only challenge was that the leather piece I was using for this was only a little wider than the jaw, so stretching and clamping it was much more difficult. I used the same plywood piece as a base; if you look closely you can see some darker patches where the holes are underneath the leather.

Once the contact adhesive had been left for 10 minutes, I flipped the jaw over onto the leather and again covered it in clamps:

This is what it looked like after trimming the excess around the edges:

The punches could then be used with the slotted bushes acting as a guide to get the holes punched in the same place. If I were doing this again, I'd drill the central hole a lot deeper in the punches and have a longer stub on the "hammering insert": it tended to fly out of the hole when I hit it and it would have been nicer for it to be better retained.

I could then use a chisel against the flat surface of the slotted bush to join the two punched holes together. This went through the leather with very little force (I guess I'm used to paring wood with it!)

The end result:

 

[Dr Al]

I started the morning thinking the only thing left to do on the bench was to fit the leather pieces to the moving jaws and then assemble everything. However, during the course of the day I had a bit of brain wave and decided to use a different method for retaining the dovetail guide. You may remember that it had been intended to be a light friction fit in the outer part of the hole, but ended up being a bit loose. Rather than try to make the hole smaller with an insert of some sort, I thought I'd just add some "bling"!

I started by drilling a 15 mm hole in the side of the foot and then drilling 11.1 mm a bit deeper. I could then screw in a threaded insert and have its head completely hidden below the surface:

A suitable chunk of brass was retrieved from my brass drawer and I put it in the three-jaw chuck and shaped it with my upside-down brass tool, a simple chamfer tool and a parting tool to cut some relief:

I then took the lazy option and used my home-made tail-stock die holder to cut an M8 thread on the end of the brass bar:

I made a quick steel insert for the rear of a collet as ER collets don't clamp very well on very short stock and having a little bit of the same diameter stock at the back of the collet makes a big difference:

I then fitted the collet chuck, clamped the brass piece (the other way round to how it was mounted in the three-jaw chuck) in the collet chuck and turned it down to 39.57 mm (which, according to my knurl calculator is the next size down from 40 mm for a good pattern with my knurls). I know many people say that you don't have to get the diameter right before knurling, but I've always had good results when I have set the diameter right and given it only takes a few seconds to do a finish pass before knurling, I always do this.

The oil pump was turned on and I got knurling:

I then put the upside-down tool back in the tool-post and turned away a lot of the excess, before chamfering both sides:

 

[Dr Al]

The dovetail guide clamp could then be fitted into its hole and tightened. I used an engineer's square to mark a line that is away from the dovetail guide in the fully-tightened position:

I then put the clamp back into its collet (with the rear spacer piece again) and into a collet block on the mill, oriented with the scribed line roughly horizontal. I then milled about 8 mm off the top:

The finished clamp (after hand-filing some chamfers around the milled flat):

This is what it looks like when locked:

Half-a-turn anticlockwise and the dovetail guide can be easily removed:

 

[Dr Al]

With that done, there was nothing left to do but assemble everything. First the moving jaws, screws and mechanisms were fitted (this was much, much easier with the lids removed):

The lids could then be fitted, using a pair of tweezers to push the hidden screws into the right place:

I then fitted four bench dogs into the top (to raise it off the surface of my bench when upside down) and flipped everything over. The buttons could then be fitted:

Here's a view of the vice jaws for the standard vice:

Here are the vice jaws for the dual-screw vice:

This is a quick test of a rather extreme taper. This is way beyond the limits of the off-the-shelf spherical seating washers (as you can see by the way the washers aren't seating against the slotted bushes), but it clamped the stock extremely rigidly. I doubt I'll ever use it for something this extreme!

Although it was always bound to work, this is a quick test of clamping long stock vertically:

 

[Dr Al]

Not much more to say really, just time for a photo-shoot.

The walnut insert on the standard vice moving jaw:

Detail shot of the dovetail guide & clamp:

This is where the portable workbench will spend most of its time:

It's surprisingly robust just sitting on the cross-cut sled and can easily be used for clamping and cutting stock without having to clamp the workbench down.

And that, as they say, is that.

 

[Fitzroy]

Brill! Not a lot else to say, except big thanks for the effort taken to document and share the build, entertaining, educational, and very interesting!

 

[Orraloon]

A lot of work went into just putting this great thread out for us to share so thanks for all the effort. And at the risk of repeating myself it surely is the dog's thingies of benchtop benches.
Regards
John