Handle side mechanism.
After i got all the components needed let’s get busy!. Basically i need to do 3 things ,make some kind of a washer for the bench vise screw to push against when tighten the vise, and a bushing to compensate the deference in diameter between the moving jaw hole and the bench vise screw, i also need to make a collar to release the vise when loosening the vise screw.
The first part is covered ,the scissor jack came with this bearing it’s wider than the moving jaw hole and it’s inner diameter is perfect for the vise screw, so i won’t make any washer for the outside of the handle mechanism.
Because the new bench vise crew diameter is smaller than the original one, i made this bushing to help lower the amount of play, it’s made from the aluminum tube i removed from the scissor jack screw itself, i just measured the thickness of the moving jaw hole and marked it on the aluminum tube than cut it with the angle grinder and removed the burr with a fill.
For the collar that is responsible for separating the jaws when loosening the vise screw, i just took a nut with a close inner diameter to the vise screw and ground the threads to make it easy to slide it in, than i made a 4 mm hole in one side of the nut and with a hand tap i made threads in it, and now the nut is turned to a set screw collar.
This was the original idea for the collar – a tube clamp to hold every thing in place. but the tube clamp tightening screw is grind on the sides of the movable jaw so i dropped the idea and use the nut as a set screw collar .
This is how the handle mechanism looks (set screw collar + washer + bushing + bearing)
This is the tricky part of all of this bench vise screw mod, the nut should be in the right position for the vise to tighten up correctly. I have a lot of ideas on how to this but i gonna stuck with the easiest way , so what i gonna be doing is cutting a piece of angle steel and drill two holes in it and use it as a bracket to secure the nut in the right position.
Okay, here is the 20×20 angle steel cut with an angle grinder to length of the vise’s square hole, i put the nut with angle steel piece to get an idea where i should make a hole in the nut.
I drilled and countersink a 4 mm hole in the nut, the hole position is just approximative because the right position of the nut will depend on the hole in the bracket.
The hole that holds the bracket with the vise, i made it by putting the bracket in its place, than mark the hole from the other side. i had to adjust the hole a little bit with a file to be coaxial with the exiting threaded hole in the vise. And for the hole that holds the nut, i bolted in the bracket in place then screwed the nut in the vise screw and i made sure the bench vise screw was parallel with movable jaw than marked the nut’s position, i removed the nut and the bracket then put them together and i marked the hole location and i drilled it.
You can see the assembly, 4 mm countersunk bolt with 2 nuts and the washer-face screw that gonna hold the bracket with the vise
This how the results took like, BUT there is two problems with this, the nut grind on the inside top of the movable jaw, it really noticeable when the vise is about to be fully closed, the second problem is the bracket i made is kinda small i am planning to weld the nut with the bracket in the future but it should be strong enough as it is, SO i will have to cut a new bigger bracket and shorten the nut.
so i guess there will be a third part of this project 😀