I'm just the opposite. I've never had very good success with the nova chuck
in expansion mode. I turn everything with a tennon and never had one come
loose. I've broken the wood with a catch using both methods so neither
seems to have an advantage there for me. Do you think our different
experiences are related to our turning methods or just coincidence?
Tony Manella
ndd1"at"prolog.net (remove "at")
http://home.ptd.net/~ndd1/
Lehigh Valley Woodturners
http://www.lehighvalleywoodturners.com/

"Steve Wolfe" wrote in message
...
I have found that I get better results when I use a tennon instead of a
recess - the chuck can get a bettr bit in the compression mode versus
the
expansion mode - you may want to try using a tennon and then jam
chucking
the bowl to finish the bottom

With my Nova chuck (although the original author has a compact version),
I
get MUCH better grip in expansion vs. compression. Don't get me wrong,
the
compression is great, but in expansion, I get more solid holding with less
visible marring of the wood.

I rarely, if ever, make the recess (or a tenon, for that matter) the
full
depth of the jaw's dovetail. I just make sure that the angle of the
recess/tenon is such that the farthest point of the dovetail is what makes
contact first, and then things go great. Good enough, in fact, that a
year
or so ago when I first tried purpleheart and made a rather stupid mistake,
I
broke the tenon off of the piece before the grip of the chuck gave up.

steve