Notice a gap starts to form at bottom of jaw when you start to loosen the bolts to adjust the vise. Is there an official setting…gap measurement? Don’t want it too loose or uneven in adjustment. Not sure how much the jaws should be able to move down when applying force. Doesn’t seem like it takes much for it to work but it doesn’t take much for them to have much movement.
In my opinion, they should have the minimum amount of movement necessary to keep the part flat against the vise floor or your parallels. That’s not a precise answer because everyone has different technique when placing their stock. Do you take the time to get the part snugged, tap it down with a dead blow?
I do what I can… but notice a huge difference when utilizing the downward force the jaws provide. I started out without the jaws adjusted and used pressure, tap it down, sneak up on full tight, etc. but still had parallels moving around, part bowing up (thin part) and not consistent. Once adjusting the jaws, noticed great improvement on the downward pressure the part applied to the parallels. I noticed the adjustment was very subjective and not very controlled from one side to the other. Wondering if there was an official process, procedure and or setting (like feeler gage) to adjust the jaws more accurately and or consistently. Its also a bit of practice applying the right amount of camping force. The lead screw is pretty easy to crank on but doesn’t seem to really need more than a 1/4 turn.
I’ve always erred on the side of having more jaw travel than needed. It means the jaws will slip against the material at some point, being that the material is pulled down tight and the jaw is still not seated fully yet. It comes in handy for saw cuts that may be a little less than square 
I’d rather have that than the jaws seat fully before having a good draw down on the part.
From the engineering side of it, you’d only really need about .010" max lift on the jaws to get most or all of the draw down effect on good square material. I’d make a rough guess that my jaws are closer to .050" since I run them on the loose side. It just requires a few “love taps” with the rubber mallet to seat the parts and jaws sometimes.
2 Likes