Jim Stewart wrote:
To have precision, you need rigidity
and to have rigidity (assuming you're looking at
building a traditional lathe) you need mass and
lots of it.

Utter nonsense, you don't know what you are talking about! Have you
ever heard of watchmakers lathes? Yes the ones to make watch parts.
There is practically nothing that is machined anywhere with greater
precision.

Ever heard of Levin lathes? The most precise micro lathes in the world.
They only weigh a few pounds. They cost a fortune.
http://www.levinlathe.com/

Abrasha
http://www.abrasha.com