jam chuck advice

Re: jam chuck advice

Don Orr

>I use jam chucks often to work on the bottom of pieces. I mount a scrap of whatever I have, usually just construction lumber like 2 x 10, turn it round and carefully cut a groove in it to hold the bowl snuggly and centered. Bring up the tail center for support and gently clean up the foot. Works fairly well. On smaller bowls I can some times work without the tail support and get the whole bottom cleaned up if the jam chuck is a real good fit. Helps to drill a hole in the jam chuck so you can push the bowl out when done if it's real tight.

Good luck and let us see what you come up with.

Re: jam chuck advice

Mike Rubes, Apex, NC

>Hi Ken,

I've really good luck with the method that Don described. I often use just 3/4 inch ply as the backer material (or whatever is handy) and also cut a groove to hold the rim of the bowl.

In addition, I've also found it really helpful to mark the center of the foot/tenon when rough turning so that I have a good idea where it is when I go back to trim the foot.

In the cases where I am doing a natural edged bowl and cannot use the "plate" method, then I just try to rely on the center mark in the tenon when I bring up the tailstock. Also, I try to use a really rounded and even piece in the headstock to put in the bottom of the bowl. I sometimes do have to adjust the center in the tailstock to get a good fit and for the bowl to turn evenly.

Good luck,

Mike

Re: jam chuck advice

ken chase

>Thanks. I see now the problem. I didn't realize it was necessary to make a custom fit chuck for each piece. I was just using a generic piece for most of the bowls. No wonder! This advice is totally terriffic!

Re: jam chuck advice

JL

>Another method is to get a cylinder (metal, PVC pipe). Either mount it on a faceplate by either turning a groove the diameter of the cylinder on a sacrificial piece of wood screwed to the faceplate or by turning the sacrificial wood to a slight taper to fit the inside of the cylinder. Epoxy or press fit the cylinder to the plate. Pad the top of the cylinder (old mousepads work great). Put the bowl with the face to the cylinder and bring up the tailstock to press it home. You can typically turn all of the area on the bottom but the immediate area next to the live center.

Re: jam chuck advice

ken chase

>worked like a charm! You guys made my day

Re: jam chuck advice

Dick Hines

>Go the your local box store and pick up a piece of MDF board, a roll of sheet cprk and some contact cement. Cut the MDF into the largest circle you can and glue the sheet cork to one side. Screw a spare face plate to the other side. It is best if you use a spare face plate because they can be a pain in the butt to get trued up if you take it off.

Place your bowl rim to the sheet cork and bring up the tail stock. Put just enough pressure to hold the bowl on to the cork. Turn the foot down

until you have a small nub. Remove the bowl and knock the nub off, helps to under cut it a bit.

It helps to leave the hole the tail stock makes in the bottom of the bowl. Line up the bowl with that.

Re: jam chuck advice

Don Henthorn

>Often if you have a pretty good fit with the jam chuck you can use some blue tape or duct tape strips to hold the bowl to the jam chick and turn the complete bottom without the tail stock. Use your critical judgment.