Restoring parallel on a side vice?

[TobyB]

I have a Hofmann & Hammer bench with an LGA single-screw side-vice .. got a good deal on it ... and building your own is a great idea, but if you don't have a bench to build it from, only a rickety Workmate, how good is your build going to be?

Anyhow ... been very happy with it generally ... but in the last few years the side vice I mainly use has been progressively drifting out of true ... when the right-hand edge just touches, the centre is now gaping about 3 mm and the left hand edge about 7 mm. For some wide bits of work it all tightens up eventually ... but not an even hold even then. Narrower work more difficult - often need to put a bit smalle block of waste in on the right if the work piece is being held to protrude on the left where I can work on it. I suspect the fact that the drive screw doesn't lie up centrally, but is probably 1/3rd-2/3rd's to the right is a cause.

What do I do about this? I know I could spend a lot of time and money rebuilding with an expensive double-screw-and-chain Veritas model, or reconditioning a quality old model off e-bay ... but looking for something simpler/cheaper if it's a workable solution. Do I strip/service/modify the vice metalwork? Do I replace (or just wedge/shim/re-shape) the external (both) vice jaw faces? Anything I can do too prevent further drift ... or is this just a cheap/bad design?

 

[Alf]

Toby, try this thread for size (other forum threads are available and the value of the information therein may go down as well as up...). As Paul sez there, most designs of vice rack (Or is it wrack? I'm never sure). Of course some designs are more liable to it than others, but either way a packing piece/device is a generally needed eventually. Sad but true.

 

[No skills]

I know very little about this so this is speculative.. I assume the vice has wood jaws inside the metal ones (??), if the racking cant be fixed by adjusting the mechanism somehow cants you just shim between the wood and metal jaws to make the faces even again??

I'll go away now.

 

[Shrubby]

I would mark a parallel line along the vice jaw - off the front edge of the bench. Dismantle the vice and plane the jaw down to your line. Reassemble - parallelism restored (hopefully). It might help to tighten whatever lag bolts/screws are holding the vice to the benchtop
Matt