they're not very complex pieces of machinery, but there's a few tricks. besides the usual "make sure there are no parts left over when you're finished", the one thing that comes to mind is getting the jaws "re-timed" properly. when you screw the jaws back into the T-slots it's easy to get one a thread ahead of the other, so when they're tightened all the way to the middle there's still a gap between them. if that happens, take very careful notice of which jaw reaches the outer perimeter of the base last when you unscrew them for another try -that one is a turn ahead of the other (look closely- the difference is small, it's a fine thread).
Re-installing them might be easier with a second pair of hands- have someone turn the screw while you hold the jaws. While gently pushing the jaws together keep turning the wrench counterclockwise- unscrewing them- and feel for the moment when the female thread of one jaw slips or jumps in at the start of the male shaft thread. Continue turning in that direction until you feel the other jaw do the same thing. Then switch to a clockwise motion and screw the jaws all the way in to the center of the vise. If they close completely you're finished. If not, unscrew 'em and try it again.
One other thing- Clean/degrease everything thoroughly and do not use ANY oil or grease on the vise jaw screws or T-slots- it just collects chips & crud. If you have a burning desire to lube with something, use dry graphite powder.
HEAVY rubber bands around both jaws should get them started the same time.
Also,turn the screw out,until you hear/feel the jaws seat at the first thread.
Then tighten.mike
Yea,graphite WILL contaminate EVERYTHING!
My dad brought some home from NASA,back in the day.
He thought it was so cool to shoot it into the door locks on the cars,so they wouldn't freeze up.
That was a LONNNNNNNNG lasting mistake.
If you have to lube the threads,try bees wax.
Work the screw ,then hold a rag against it while turning,to take off the excess.
I don't think you NEED to lube it though.
mike
yes, as we've all learned the hard way, graphite powder needs to be deployed verrrrrry sparingly or it will look like an overloaded pencil sharpener blew up!
Since I do diamond setting in my vise also, everytime I drop a stone and can't find it. It gets a cleaning.
One thing I found that helps with the shaving that drop off, is to put a stove burner covers turned upside down on the bench.
With the vice sitting in it. It catches some of the chips anyway and some of the stones. The second is since your not putting a
constant pressure on the vice screw, you only need light film of grease. So you don't get a lot of chips building up.
Just my two cents, but that double ended screw needs only the very lightest bit of lubrication. There's no real stress, pressure, or friction involved so wear will be very minimal in mine or your lifetime. In fact, you could place just the slightest bit of oil on a piece of cloth and wipe the threads with it much the same as you would wipe down a fine firearm.
One thing I will say is do not beat the vice closed. I've seen a couple of engravers actually take a small engraving hammer and beat the handle to close the vice on a gun part. One should NEVER use a hammer to close a vice. The threads on that screw are not designed for hammering.