Author Topic: How to hold a disc of wood to make an 8" doughnut ?  (Read 601 times)

Offline Rob Mitchell

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How to hold a disc of wood to make an 8" doughnut ?
« on: March 30, 2023, 11:56:56 AM »
I want to copy a knitting stool which has an 8" disc with a hole in the middle about 30mm.
the profile is similar to a squashed doughnut. Hence all surfaces need machining. How can I support the piece after the 1st machining. See attached photo.

Offline Bill21

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Re: How to hold a disc of wood to make an 8" doughnut ?
« Reply #1 on: March 30, 2023, 12:28:15 PM »
There are several ways of doing this but it depends on what equipment you have. One way might be to turn a spigot on the blank to accommodate the largest chuck jaws you have. After mounting on the chuck and turning the face and sides drill a 30mm hole through the middle. Then turn a tight fitting 30mm spindle onto which to replace the work. Turn the remaining side supporting the work with the tail stock if needed. Provided the piece is a snug fit on the spindle remove the tail stock to do the final turning taking care.

Another way might be to turn the first half of the piece as before and then mount it in some wood jaws attached to your chuck to turn the second side.

I personally would not use Cole jaws or a Longworth chuck but I’m sure some turners might.

Let us know how you get on when you’ve done it as it’s always nice to see others solutions to mounting work pieces.

Offline Bill21

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Offline Paul Hannaby

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Re: How to hold a disc of wood to make an 8" doughnut ?
« Reply #3 on: March 30, 2023, 10:22:23 PM »
I do something similar when making clocks and use cole jaws to grip the piece of wood either on the outside edge or the inner edge.

Offline The Bowler Hatted Turner

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Re: How to hold a disc of wood to make an 8" doughnut ?
« Reply #4 on: April 03, 2023, 11:07:31 PM »
Rob one way of doing this would be to turn a spigot to the size of the hole in the middle.This can be held in a chuck or on a faceplate or even turned to fit the morse taper. With it fixed in the lathe drill a hole down the center and then turn a tapered plug to fit in the hole..So the first machining should be to make the hole and then you can mount it on this mandrel to turn either side.