Work centering under a microscope can be done in two ways; (1) with a centering vise which have mechanical limitations and are expensive or; (2) by moving the entire vise. Being a short person the amount of inches between the surface vise sets on and the eye pieces becomes critical when when using a .40 Barlow Lense in the scope so the device has to be a minimum vertical height or depth.
Due to the cost of a centering vice and since 99% of my engraving is done by air assist tools I decided to see if I could come up with a means of moving the entire vice for centering my work. I tried may different plastic slider pads and found them to be sticky at the wrong time if I was moving the vise and cutting at the same time. After going through the pad exercise I decided that in order to get the smoothness I wanted the vise would have to set on a ball bearing surface.
The device I created requires minimum space beneath engravers vice to function. The engravers vice base sets on a bed if ball bearings which allows the vice to move smoothly and freely and I can cut while moving the ball around. I have buffered the ball bearings so the vice moves only when pressure is applied to move it and it stops moving immediately when pressure is taken off.
Attached are some photo's of my bench which I made to engrave barreled actions and other long objects and my centering device with the dust-trash cover on and off.