David,

I use both a Nova Compac chuck and a Super Nova on my Jet Mini as I have for
almost 2 years with no problems to date. You will notice a bit of a
"flywheel effect" because of the heavier weight of the Super Nova, but it
has caused me no problems.

I have read various other posts about the added stresses on the headstock
bearings caused by larger and heavier chucks. I don't quite buy their
arguments. The added stresses do not result from the rotation of the chuck
or the forces resulting from tightening the chuck.

The real cause of added stresses on headstock bearings is because with a
bigger and better chuck, you may tend to turn larger and heavier blanks, but
you are still limited by the capacity of the Jet Mini (10" D X 14" L). The
real stresses are caused by turning these larger blanks and using larger
tools which, in turn, generate more leverage against the headstock bearings.
Another factor is that larger chucks tend to "hang" further from the
headstock, which also causes some added stresses.

None of this would stop me from using a Super Nova chuck on a Jet Mini
Lathe. Besides, if you wear out the bearings, just replace them.

Barry


"David Claborn" wrote in message
...
I've heard conflicting reports on whether or not a Supernova chuck is too
heavy for a Jet Mini's bushings/bearings. Is the difference in weight
really all that much?

Relatedly, doesn't the method of tightening the Nova put quite a bit of
weight on the bearings/bushings in the first place -so that the Supernova
may actually be better b/c you never have to tighten with force downward
on
the headstock?

scratching head

Thanks in advance,
Dave