Keith Young wrote:
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.

Keith,
some more information might be helpful, like the type of wood, its
green/dry status, bowl size, and the diameter and depth of the recess.
Does the bowl fall off of its own accord, or does it take a catch

In my experience the diameter of the recess is more important than the
angle of the dovetail. I say that because I do a lot of first fixings
into a shallow hole drilled with a forstner bit, so I have no dovetail
at all. Remember that the jaws have only one true diameter, that is when
they form a true circle. When expamded beyond that diameter they grip
only at the center of their arc, and at smaller diameters they grip at
the ends of their arc.

One other tip is to make sure the chuck is clean of dust and operates
smoothly and easily. If it gets gummed up, a lot of the power you apply
to the key is expended overcoming friction, and it is difficult to get
any feel for how tight the jaws are. You really shouldn't have to crank
too hard on the key to hold a bowl. I periodically blow all the sanding
dust out of the chuck and give the threads a little graphite lubricant.
The jaws should then operate with just the lightest touch.

For final fixing I make the dovetail with a small detail gouge so the
edges are nice and clean. The bottom of the recess is finished with a
flat scraper, the finished shape of the recess erring towards concave.


--
Derek Andrews, woodturner

http://www.seafoamwoodturning.com
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