You're thinking in the wrong direction. You make the recess so that the
chuck jaws wedge themselves against the bottom of the recess, not the sides.
Woodworking 090 tells you don't try to put a round peg/nail/chuck in a round
hole in wood, it'll split.

Thought I had sent you a reference to my page where the standard NOVA is
used, but in case not,
try. http://personalpages.tds.net/~upgeorge/index.html and look at the
methods, using recesses. You want to keep the area where the jaw faces meet
the bottom of the bowl smooth, and free of dust. Further, especially with
wet wood, or weak sapwood, reinforce with water-thin CA, remembering to
scrape irregularities with your skew or clean up with your pointy gouge to
get a nice wedge.

"Keith Young" wrote in message
...
Hi

Does the recess have to be perfect. I have a nova compact chuck.
Currently
no matter what I try to secure the chuck to the wood, I can tighten enough
to keep the wood secure. I believe that i have the correct angle.Maybe the
cut isn,t clean enough.

Any suggestions
Keith