--Investigate the air-over-oil system. Can't describe it, but I
worked at a place once that made a number of these as low-budget retrofits
for surface grinders (actually wafer slice-and-dice machines). It used
compressed air, oil-filled pistons and limit switches to drive the table
back and forth.

--
"Steamboat Ed" Haas : Just another Fart in
Hacking the Trailing Edge! : the Elevator of Life...
http://www.nmpproducts.com/intro.htm
---Decks a-wash in a sea of words---