Jumbo Jaws

[Dan Williams]

Can anyone tell me, Can you use thoes type jaws as a expanstion chuck ? Like when you finish the bottom of a bowl. Instead of holding the exterior of the bowl, expand internaly.

I hope I said this right

Thanks
Dan

[Glenn Hodges]

Dan, you turn a depression in the bottom of the bowl. Make sure the sides of the depression straight up and down. You set the chuck inside the depression and expand the jaws of the chuck so the jaws will make contact with the sides of the depression. This needs to be tight, but do not over do it because you can cause the sides to crack especially if the sides are not thick enough.

[Ben Gastfriend]

If you are talking about reverse chucking to finish off the foot, my concerns are:

1. The little rubber pegs are sloped inwards to hold the bowl from the outside, the contour will probably be incorrect gripping from the inside.

but... if you use a light touch, and grip lightly from the inside and bring up the tailstock, it'll probably work like a jam chuck. Just be sure you're wearing the face sheild in case it spins off the lathe.

[Gordon Seto]

Dan,

You are talking about the Cole jaw that used for reverse chucking.
Yes, it depends on the rim design. Use some shrink wrap tape on the outer edge as insurance.
http://www.rockler.com/product.cfm?page=10207&filter=17675
Turn down the speed, use the tailstock as long as possible.

[Bill Bolen]

Sure, if your piece has an inward sloping lip it will hold nice and tight, but if you put too much pressure on it it can split. DAMHIKT!!Bill..

[Allen Neighbors]

Ditto what William Bolen said.
Like for finishing the bottom on a bowl that's of a 'calabash' design, where the top rim of the bowl is smaller diameter than the middle of the bowl. I've used my Cole Jaws with that type of bowl many times. Now I use my longworth chuck the same way. It works.