On Feb 12, 9:09*pm, "Michael Koblic" wrote:
...
Here is a question then: Say you have a 9" swing lathe and a 8" diameter,
...
Michael Koblic,

One of my old books shows an offset spindle added to a lathe to turn
oversized disks. A gear or pulley on the main spindle turns the
faceplate on the new spindle at a reduced speed. The geometry is
difficult with pulleys but the planetary reduction off a burned-out
electric winch might fit well, bolt the large internal ring gear to
the faceplate and drive it with the small sun gear.

The added spindle goes above and behind the main one so the tool post
is still in the right front-rear position.

jsw