Doughnut Chuck

by tomatoskins

29K12919

Intro: Doughnut Chuck

A Doughnut Chuck is a great jig to hold turned bowls on a lathe. It grants access to flatten and finish the bottom of any bowl. This simple chuck can be made in an afternoon and can be customized to fit any lathe and bowl.

STEP 1: Tools and Materials

Tools:

Materials

STEP 2: Hardwood Tennon

Glue two pieces of hardwood together to make a blank that will hold the doughnut chuck on a face plate or nova chuck.

Mark the center of the hardwood. Cut the corners off using a bandsaw and mount it between centers.

STEP 3: Turn Tenon

Turn the block round and create a tenon on one end (if using a face plate just turn flat). Remove from the centers and mount in the chuck. Turn the face of the block flat. Verify with a straight edge.

STEP 4: Cut Circles

My lathe has 6 inches of clearance between the headstock and the bed. Because of this, I cut the radius of my circles a half an inch shorter to ensure that the two disks spun clear of the bed. Cut out the circles with a bandsaw or jig saw.

STEP 5: Glue and Turn Circles

I used regular wood glue to attach the circles to the hardwood. Use the tailstock of the lathe to clamp the circles in place. Once the glue is dry, turn the circles round.

STEP 6: Drill Holes

Mark a line around the face of the disc a half inch in from the edge. Drill four 1/4 inch holes around the edge along the line previously marked.

STEP 7: Insert T-Nuts

Drill a hole from the back side the size of the t-nut. Tap the t-nut in place. Mark index numbers on the face plate.

STEP 8: Mark and Part Inner Ring

Measure the size of bowl you want to hold in the chuck. My bowl needed a chuck with a 7 inch diameter hole. Mark the hole and use a parting tool to remove the circle.

STEP 9: Install Foam Lining

Multiply the inner diameter of the ring with pi (3.14). This will give you the needed circumference of the foam lining. Add two inches because the foam will compress and cut to length. Open the split side and place it over the inner circle. This will give padding when holding the bowls in place.

STEP 10: Finish the Bottom of the Bowl

Attach the loose ring with bolts and washers. To place a bowl in the doughnut chuck, loosen all bolts (removing one) and slide a bowl in from the side. Tighten all bolts equally (I use a socket in my drill for quick changes). Now go flatten and finish the bottom of any bowl.

This doughnut chuck took inspiration from two great videos by Peter Brown and Gord Rock. Go check out their projects for other great ideas to implement on the lathe.

15 Comments

mlitzkow22 6 years ago

I have a set of Cole jaws. Depending on the shape of the bowl, they are not always very secure. It can be a problem when the sides of the bowl are close to vertical close to the rim. This looks like a nice alternative. With turning it's not either/or, but more options is always better.

askjerry 6 years ago

Sometimes you find an idea so simple that you wonder why you didn't think of it... this is one of those ideas!
Outstanding!

WyldStyl3 6 years ago

Is that blue bowl made of wood or is it just a bowl you put in the chuck to show how it works for the instructable?

WyldStyl3 6 years ago

Thanks XTL, but you're a little late to the party. That instructable wasn't up yet when I asked that question.

tomatoskins 6 years ago

That is actually a bowl made from half a bowling ball. That instructable should be out sometime over the next few days.

Mihsin 6 years ago

Years ago, I wanted to drill and tap a hole in a billiard ball, but didn't know how. Thanks to you and the other two gentlemen you referenced to. Now I'm too old for the job I was after.

Best regards

BigAndRed 6 years ago

good idea but very limited to size bowl you can finish with it.

In your link for the nova chuck there is this 'NOVA 6006 Mini Cole Chuck Accessory Jaw Set'

https://www.amazon.com/NOVA-6006-Mini-Chuck-Access...

the soft grip wedge pieces could be screwed onto your wooden face plate then have several rows of threaded holes for different sizes like the cole jaws, you could even make then out of soft wood.

What is the material the blue bowl is made from, looks interesting?

tomatoskins 6 years ago

That is definitely an option, and I believe that Marius Hornberger made one once. However, not knowing how grippy this bowl would be (made from half a bowling ball) I opted for this more secure chuck. I will probably be making a set of Cole jaws sometime in the future.

BigAndRed 6 years ago

to make it more secure have you considered using gaffa tape to wrap the bowl and chuck for that extra insurance. I do on jobs that are off center or only just held on by the jaws.

BigAndRed 6 years ago

I had some challenge holding bowls to finish the spigot till I got this set of cole jaws, if I had seen your doughnut chuck first I would of made 1.

DonS89 6 years ago

Sweet! Going to have to make one.

bwatt1 6 years ago

This is a really cool idea.