My vise isn’t at 90 degrees

[old martParticipant @oldmart]

At least the jaw is tilted in the best direction for holding work, does the gap show up when the moving jaw gets close to the fixed one?

[Neil LickfoldParticipant @neillickfold44316]

Did you check the squareness of the Fixed jaw block ? Did you do a blue test of the block to the bed by chance? Did you also check that there is no binding on the side of the screws through the vice base to the Fixed jaw block?

The fixed block can be squared up if you know the amount out that it is off true. Then set it up on an angle plate, and use an indicator to get the correct compensation, then mill the surface so that when assembled ect it will now be square. You actually don’t want it dead square, but a couple of microns with the top touching before the bottom. The load of the jaw closing and distorting the vice body, will then become square.

You can measure this deflection in your vice, by clamping up a square, running an indicator over the surface and see the amount difference. Then tighten the vice to the amount that you normally would. Then look at the amount difference again. With this info you can then correct the vice to get consistent results for your machine.

Neil

[moonmanParticipant @moonman]

Well I spent the evening ripping the vice to bits and found some wonderful stuff.

Every edge you see is chamfered, every edge you cannot see isn’t. Resulting in a burr which would mean the fixed jaw would rock once you unscrewed it from underneath.

I gave it all a good clean up, stoned in some chamfers and checked again for squareness, it’s much better, a tiny bit of tilt remains but by the sound of it that’s fine. I can only assume it was a bur preventing this from the start.

My mill was also slightly out of tram and I was correct, there’s 2 thou of nod. I have some shim stock on the way and intend to fix that but I’m not looking forward to it, I can see this being a huge pain in the rear end.

[Author]

Posts