"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message

It must not have been much of a machine to simply move a hone
back and forth! That could be done with one long cylinder a valve,
and two
limit switches. (and it would probably be straight, if not round)

Lloyd

I spent a couple of years of apprenticeship on the nitty-gritty of
designing large accurate machines, meaning those with structural
members too large to drill and mill precisely at one clamping on the
Bridgeport. I can locate holes to 0.005" manually without too high a
scrap rate.

I used one of those tricks last week to open up the hole through an
irregular-shaped part.
-jsw