Chuck jaws - Inside & Outside?

[Toney Robertson]

I am working on my bowl and I am ready to form the tenon. Are all chuck jaws made to clamp tenons and recesses?

I have four chucks and some extra jaws. All jaws have a dovetail on the outside. Some have a dovetail on the inside and some have a ridge at the top of the jaws. The Nova chuck instructions I down loaded off the net only talked about using a recess, nothing about a tenon.

The ones with the ridges is one I would like to use because of it's size. Would it safely clamp on a tenon?

I hope I have made myself clear, if not I could take some pictures.

TIA

Toney

[Bill Bolen]

Sounds like the jaws are straight? The ridges sound similar to the "shark jaws" I've seen. I don't think you will have any problem gripping onto a tennon...Bill...

[Kevin McPeek]

One of the most important things is how your blank contacts the jaw faces. A tenon can be pretty forgiving but if it is too long and hits the bottom of the jaws before the blank hits the jaw faces it will get knocked off center easily. If you are using Nova jaws you should use a dovetail tenon. It really only needs to be about 1/4 to 3/8 tall with a nice flat surface to register on the jaw faces. An easy way to make a dovetail tenon is to make it square just a hair oversize and then lay a skew on its side and use it like a scraper to cut the dovetail in with the long point.
Clear as mud?
As for a recess, I found that in bowl turning they tend to break out because there isn't much meat around them to support it. I guess if you have a fat bottom bowl there might be but then people can always tell how you held the bowl to turn it. They work great on platters and plates though, and you can make them pretty shallow to hide them.