Repair a broken vise

[sardine]

Crowsfoot stamp = army issued.

 

[Screwdriver]

Crowsfoot stamp = army issued.

Aha! So possibly ex. MoD?

 

[pedrobedro]

Crowsfoot stamp = army issued.

Its the MOD stamp, could be any of the Forces

 

[galooph]

Front jaw unit is fine, just need to take off the handle, straighten and replace. Incidentally, anyone got any tips for the best way to do that?

On my Record, I gave up with the bent handle and made a new one. I used some stainless bar which I threaded at both ends to take a couple of stainless balls I found on eBay.

 

[Mr shiney]

I would braze not TIG. I TIGd mine first time and it came apart. braze is still going strong.

 

[MattF]

Front jaw unit is fine, just need to take off the handle, straighten and replace. Incidentally, anyone got any tips for the best way to do that?

Various ways of doing it. Press, flypress, large vice or heavy mallet. Method is similar whichever way you apply the straightening force. You want two blocks, one either side of the bend, placed at least an inch or two away from the bend, with the bend facing upwards. Then, either whack the bend with the mallet else gradually press down on the bend if using the other methods. You need to push it beyond straight when pressing it to allow for the slight springback, else if beating it with the mallet, just keep beating until it's straight. You could also just heat the bend to red hot with the O/A rig and straighten it that way.

 

[Pete.]

What I would do here is un-bolt that pipe jaw, file the broken bit somewhere near flat then clamp a slab of ally in the gap between the jaw seats. Make your repair piece and G-clamp that to the ally slab so the tops are level. Now braze the repair into place - the braze obviously won't stick to the ally but should fill the gaps and make a nice seat for the back jaw. Plunge a drill through the two mount holes, right through the ally and the repair part to accept the new jaws.

Those pipe jaws are pretty useless TBH, they marr work with even very light pressure yet are hard to clamp securely because of the shallow angle and sharp tooth edge. I would make some ally V-jaws for clamping chromed parts like fork legs. Much more useful.

 

[Screwdriver]

Like the sound of that thanks Pete. I was thinking of filing it flat, much better idea to clamp in a chunk of alloy!

Swindens went quiet when I declined their offer to fix it for £275 so I don't even know if I can get a replacement jaw. I was thinking of making up some copper jaws because I rather suspect this will end up on the welding bench! Either way, for motorcycle use, might be better off with a V jaw, rather than the curve.

Incidentally I note the later models no longer have this type of through jaw bolt. Clearly it does weaken the part where it has snapped. The rest of the vice looks super strong.

What is the best way to get the handle off. I have a fly press and a really decent lathe to repair/make new bt I would like to take it off with the intention of putting the same piece back.

 

[MattF]

Incidentally I note the later models no longer have this type of through jaw bolt. Clearly it does weaken the part where it has snapped. The rest of the vice looks super strong.

Through the jaw bolts are preferable to insert side screws, in general. That method has been in use by Swindens since they first started making vices, up until they changed to using screws, and most heavy duty vices used through the jaw bolts. It's not an inherently weak design. Let an ape with a hammer loose though, and anything can be broken.

What is the best way to get the handle off. I have a fly press and a really decent lathe to repair/make new bt I would like to take it off with the intention of putting the same piece back.

You mean how to remove the screw and handle from the front jaw, or how to remove the handle from the screw?

 

[Screwdriver]

Handle from screw. Looks like an interference fit collar, then peened over. I'm guessing I might be able to ease it with a grinder then press it out on the flypress.

S.

 

[MattF]

If they use the same method for attaching the handle balls as they used to, the one I removed had the ball top countersunk, and then a bead of weld run to hold the handle and ball together, if I recall correctly. I'll dig it out later and have another look to check. I'd just cut the ball off and go from there. You'll only lose an inch or two tops from the handle length, and if it is simply a peened/pressed end, you can easily part the ball from the cut stub of the handle once you've cut it off.

You can easily straighten that handle without parting the assembly though. You've plenty of clear length to work with.


Edit: This is one simple example of straightening. This one was only a thin handle, so easily done in a vice, but it demonstrates the basic principle. The central copper strip on the front jaw was pressing against the bend, and the two plywood strips were to give clearance for taking it just past the point of springback.

 

[Screwdriver]

Thanks, I'll probably use this handsome beast...

 

[MattF]

You should be able to do it easily in that without removing the handle from the screw. If you have some old Vee blocks, those would be the perfect things to use. One either side, above the Tee slot sections on the flypress base. Sit the handle in those and then just have a slug of brass/bronze/copper etc. underneath the ram to press on the bend. That's pretty much all that the traditional straightening presses were, in design. The wider apart that you place the Vee blocks, (or blocks of wood, metal or whatever else you have to hand), the less pressure you need to apply to the bend, as a rule, but you also have less control over warping if you place the support blocks too far apart.

 

[Screwdriver]

Thanks. I built that entire workshop myself. I refurbish/restore old machinery for my hobby which is restoring motorcycles and building "specials".

I will strip the handle apart anyway for inspection/cleaning and my preference is as always to keep as much of the original machine intact as possible. I'm a sucker for the patina and signs of use for old machinery. I know a brand new handle would be both easier and "better" but it would look wrong imho so I am hoping for a non destructive disassembly.

But yes, I will easily be able to straighten a bit of bar with the tools at my disposal!

S.

 

[MattF]

Nice work on the workshop. That's a nice homely workshop. Much nicer than the sanitised, pristine ones which appear unused. Can't fauly you for wanting to retain originality and usage marks. I generally have no problem with modifying when it improves or makes things easier, but keeping original is always best, and I'm not a fan of removing usage marks either.

Btw, found this page earlier:

http://chestofbooks.com/home-improv...porting-Rests-Shaft-Straighteners-Part-4.html

Just thought I'd post it for reference on the topic of straightening.

 

[Screwdriver]

Pulled the screw out for a look see and to straighten the handle.

Thread looks really good except for the very end which has picked up at some stage.

I just hand filed it with a small needle file until it looked good. bar got straightened in the press. I wish I'd taken the handle apart because having that great big screw hanging off it was a real chore.

But it came out ok, not perfect.

I was expecting to find a perfectly flat machined surface for the jaws. This was a big surprise.

That's a good 0.2mm step so the perfectly flat machined and ground jaws aren't flush.

I wonder if this was a production problem, doesn't look right to me, I might even ask Swindens about it. The snapped end had the stale the other way around with the screw holes slightly below the lower mounting surface. The upper surface on that jaw snapped off.

Found some 12mm hot rolled (?) steel sheet.

And a bit of 7mm for the outer buttress.

Easiest way to cut was with a cutting disk and I moved it to the door to keep the dust out of the workshop as much as possible. Incidentally, that "vice on a plate" is possibly the best thing I even made in terms of how handy it is. Usually lives on the welding bench.

I ground the top of the vice jaw flat but there is a slope on the rear buttress which I will need to account for in the final repair piece.

Nearly there. Just need to match the piece to the remaining surfaces.

Question time:

I'll drill it out as accurately as possible to accept some bolts, probably allen headed but they are going to have to be relatively small diameter, M4-M6 at the most. What's the strongest type to use? Stainless? Can I easily get hold of some high tensile allen headed bolts?

Once drilled out, I'll offer up the pieces to use as a drill guide to get it mounted as accurately as possible. Then I'll be able to bolt the E to the vice before I braze it. Do I chamfer the edges all the way to a knife point so that there is as little contact patch as possible, meaning the largest possible amount of brazed connection? What about the very front of the mounting where the removable jaw bolts? Should that be chamfered too with a deep V?

Screwd.

 

[Pete.]

The size of the bolts isn't so much of an issue because they are only retainers, not designed to carry any clamping load. Look at the screws holding the jaws on your record vice they are probably only 1/4" slotted countersunks. The Swinden's originals were brass or bronze I think, at least they are on mine.

 

[Screwdriver]

The size of the bolts isn't so much of an issue because they are only retainers, not designed to carry any clamping load. Look at the screws holding the jaws on your record vice they are probably only 1/4" slotted countersunks. The Swinden's originals were brass or bronze I think, at least they are on mine.

No I mean the bolts which will go through the repair, into the vice body. Not the jaw bolts.

Those cylinders represent bolts I intend to use to strengthen the repair prior to brazing. Not sure if it's worth the effort of sourcing some super strong material or any old allen bolt.

S.

 

[Screwdriver]

I just need to fettle the pieces, bolt them in, weld them together then unbolt and fettle some more...

 

[Pete.]

If you got the mini-grinder out and cut/filed a step in the front you could do this and it would be very strong and not require the bolts.