Self Centering Vise/Vice

My first attempt at a Self Centering Vise/Vice, I had seen one of these type Vices online and thought it would make an interesting tool to design and make.It was a bit of a head scratch to start off with, but with some perseverance and will power I got there in the end, the 2 sliders and screws, one side is left handed and so is the thread, the facing slider is the left hand thread and as you turn it anti clockwise it opens the jaws.Assembly is as follows, ensure the 2 screw threads joints are clean, file them if necessary, screw each screw into the corresponding slider, the end of the screw fits into the recess on each slider, apply some CA Glue or 2 Part resin to the centers, be careful not to get any glue on the outer edges, with both screws screwed in as far as they can go, push the 2 sliders together and wrap an elastic band around the slider until the glue has dried.The next part is to push the sliders onto the rails, the threaded screw will fit nicely in the end cap recess, you