On May 14, 9:24 am, Wes wrote:
I'm leaning towards the 4 jaw independent. Thoughts.

Wes

3jaw, if you want to get anything done without spending huge amounts
of time in setting up.

reasons?
a)using it as a rotary table, you will centre it under the mill
spindle with the x-y mill controls. so it doesn't matter if its out a
bit in the chuck.
b)using it horizontally as an indexing head, the major fixed
adjustment is determined by your tailstock - you adjust the other end
to this, and check levels/eccentricity. There is adjustment in the
divider head to get it really close.

And unless your machinery is in absolute, first class, no wear,
calibrated condition - slop in othere areas is going to be the
limiting factor, not the 3 or 4 jaw chuck.

(the above I learnt at trade school, in 'Basic Milling")

Andrew VK3BFA.