"Jim Wilkins" fired this volley in news:ln5941$2os$1
@dont-email.me:

While a hydraulic cylinder rebuilder was proudly showing me the large
honing machine he had designed, he mentioned that the requirement is
for smoothness, not straightness or roundness. The seals have
relatively a lot of compliance.

Smoothness (only) can be accomplished with a simple flexible hone or the
older standard "cylinder hone" with a flexing frame and solid 'bone style'
grit bars. 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