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[VisExp]

I made a donut chuck this weekend to help me finish the bottom of bowls. If you like to see how it was made you can visit my blog.

 

[Wildman]

Outstanding design!

Everyone I've ever made used only four bolts located at 6 & 12, 3 & 9, wing nuts make the chuck very easy to use.

 

[VisExp]

Thanks Wildman.

 

[Mather323]

Great job, thanks.

 

[marcruby]

I can't tell from the pictures whether you did this or not but a useful variation is to face the inside of the donut with leather. Leave it overhang the inside hole a little bit any you have a nice gasket that prevents any wood to wood marks.

Marc

 

[Fred]

Nice donut jig. I have made quite a few out of MDF and found that a beveled edge on the inside really helped to 'seat' the bowl easier. It also will help to eliminate the scrubbing that can happen IF you ever get a catch. The MDF also will not scratch quite as bad as wood will. Lining the inside rim with a strip of a thin shammy cloth works quite well. Experiment my friend and see what works best for you. :biggrin:

Another improvement is to turn a foot to allow mounting the device in your chuck. Then to ensure repeat centering, turn a piece of pipe and securely glue it over the foot. Then when you remount the donut into the chuck the jaws will not bite into the wooden foot and deform it like it can do after a bit of use.

I concur with the suggestion that you use wing nuts since they are far easier/quicker to remove. Also, four - or six at the most - bolts are sufficient to mount the bowl being turned. Just be sure to equally space these around the donut for balance. Round headed bolts will also protect the hands a bit better. Just keep the wing nuts to the headstock side of your work and DO NOT EVER FORGET they are there. It is amazing as to the amount of flesh that is instantly removed if one does forget. I need to get pictures of my friends mangled fingers from where he "forgot!"

 

[VisExp]

I can't tell from the pictures whether you did this or not but a useful variation is to face the inside of the donut with leather. Leave it overhang the inside hole a little bit any you have a nice gasket that prevents any wood to wood marks.

Marc, it's difficult to see in the picture, but I attached a piece of high friction router mat to the inside face of the donut ring to help hold the work piece and protect it.

 

[PaulDoug]

Another improvement is to turn a foot to allow mounting the device in your chuck. Then to ensure repeat centering, turn a piece of pipe and securely glue it over the foot. Then when you remount the donut into the chuck the jaws will not bite into the wooden foot and deform it like it can do after a bit of use.

Fred, I can't quite picture what you mean by "turn a piece of pipe". Can you explain that a little more for a dummy? I have a bowl setting on my lathe wating for me to make one of these chucks so I can finish it.

 

[TellicoTurning]

Keith,
Great design... I've seen one similar, but not quite like yours... I like the idea of the T-nuts... with a variety of bolt lengths you can adjust the gap as needed for different size bowls and not have those wing nuts whirling on the back side of the chuck.

I have one started on a dedicated face plate myself, but haven't finished the actual donut... again, I "borrowed" your idea and converted to PDF for my shop/jigs file... I think I'll finish mine same as your design... but now I will definitely have to get another face plate... thanks for posting.

 

[PaulDoug]

Been think'n (oh oh) instead of using wing nuts on the bolts how about putting "t" nuts on the back side and using round head slotted machine screws tp hold the pieces together? Eliminate the knuckle-busters. Probably take a few more seconds to put it together, but safer.

 

[VisExp]

Fred, I can't quite picture what you mean by "turn a piece of pipe".

I think what Fred means is to turn a piece of PVC pipe so that it fits on the tenon on the backside of the donut chuck. That way the jaw chuck would be gripping on the PVC instead of a wooden tenon. Over time a wooden tenon would get beat up and deformed. This is assuming you are not dedicating a face plate to the donut chuck and are using a jaw chuck instead.

Been think'n (oh oh) instead of using wing nuts on the bolts how about putting "t" nuts on the back side and using round head slotted machine screws tp hold the pieces together? Eliminate the knuckle-busters. Probably take a few more seconds to put it together, but safer.

I did use t-nuts on the back plate. I wanted to use round head slotted machine screws but I couldn't find them at Lowe's.