mac davis (in firstname.lastname@example.org) said:
| Maybe a CNC version of that Legacy Milling Machine Bill Grumbine
That comes fairly close. The legacy appears to be an x-y machine, with
the y-axis at a fixed height, which might be a bit restrictive for an
application like Art's.
Keep the long x-axis, dispose of the y-axis altogether, and add a
(vertical) z-axis with just over a foot of travel. Replace the hand
wheels and indexer mechanism with PC-controlled stepper motors; and
you'll have something closer to what I'd imagined.
I think I'd weld up the machine from 4" square steel tubing - the
Legacy's aluminum rails just aren't "beefy" enough to hold that much
mass. The same (80/20?) rails and slides could probably be used if
they were secured to the steel structure - but I'm not sure if they're
available in 10+foot lengths. The ball-type lead screw could be used
if precision isn't a significant factor, or a finer pitch Acme lead
screw could be used if it is.
The challenge would be in arriving at a good balance of torque and
precision to rotate that much mass. An "easy-button" solution would be
a large ring gear driven by however many steppers it'd take (the
larger the ring gear, the greater the available precision).
Like I said, an interesting project. :-)
DeSoto, Iowa USA