Donut Chuck Centering

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I've created a donut chuck (my second one) and I can get by using it to finish the bottom of my bowls, but I always find that I can't get the bowl perfectly centered in the chuck. As you could tell, this can be frustrating, time consuming, and result in poor finishing of the bottom of the bowl.

Is this a common problem with donut chucks? Is there any way to work around / resolve the issue?

What other methods are recommended for finishing the foot that would eliminate this problem?

Thanks!
 
Donut chuck centering

You should have a centering point in the bottom,just line the tail stock up to it,then once it's centered then then I put a small piece of wood up against the botom so you don't make another indention,and you should be able to clean the bottom up pretty good,then whatever little spot that is left over,you can just touch up by hand.
 
I've seldom (if ever) been able to get a reversed piece lined up exactly and running perfectly true. As Ken mentioned, I use the dimple in the tenon (which was created when I turned the tenon) as a starting point, then tweak things by hand if necessary to get it turning as true as I can. Any final small irregularities get sanded and blended into the piece, so it's not noticeable in the end.
 
What I use for centering a piece in my donut chuck or vacuum chuck is a Tailstock Chuck Adapter. I got mine form CSUSA. When you have finished turning the piece and are ready to turn it around to finish the bottom the piece in the chuck is mounted in your tailstock. Unscrew the chuck from the headstock and screw it onto this adapter. Bring up the piece to your donut chuck or vac chuck. Either tighten or turn on the chuck. Release the chuck and finish the bottom. It is perfectly centered. No muss no fuss.

http://www.woodturnerscatalog.com/s...cking_Alignment_Adapter___reverse_chuck?Args=
 

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Thanks for sharing that secret Bernie. Thats a neat idea with i had thought of something like that even for the Longworth Chuck i have made. :thumb:

Thats a very fair price in my view.
 
Bernie.........not using a vacum chuck.....I dont understand how this adapter works..............you turn your bowl and leave it in the chuck but take it off the headstock and place the adapter on your chuck...then place it in your tail stock......slide it forward ......to what ? and how do you finish the bottom off this way with the chuck in the tailstock.....guess im not following what your saying correctly...........??? thanks
 
Bernie.........not using a vacum chuck.....I dont understand how this adapter works..............you turn your bowl and leave it in the chuck but take it off the headstock and place the adapter on your chuck...then place it in your tail stock......slide it forward ......to what ? and how do you finish the bottom off this way with the chuck in the tailstock.....guess im not following what your saying correctly...........??? thanks

The tailstock adaptor holds the piece in place long enough for you to get it centered and attached to the spindle...either with a vacuum chuck or a donut chuck. Once you have it secured at the headstock, you remove your chuck and the tailstock adaptor and finish off the bottom of the piece.

I've got one like Bernie showed, but it's solid, so it's not able to spin. Later, I got an adaptor that attaches to the PM or Oneway live center, and allows the chuck to spin when it's attached to the tailstock. Even though you don't normally need the ability for the chuck to turn (since you'll typically be removing it before doing any cutting), I prefer to be able to turn the piece if needed as I'm attaching it to the vacuum or donut chuck.
 
Dan what I do is after the bowl has been turned and ready for the bottom to be finished is I leave the bowl attached to the chuck. I unscrew the chuck from the headstock spindle. I attach the one piece of the donut chuck to the headstock. I screw the adapter that is shown in my post into the chuck with the bowl. Before I slip the adapter into the tailstock I slip on the other half of the donut chuck then mount the adapter, chuck and donut hole to the tailstock. I then bring the tailstock up tighten it then screw the tailstock until the bowl touches the donut chuck that is mounted on the headstock. I secure the bowl into the donut chuck which is perfectly centered and then remove the chuck from the bottom. The bowl is secured and centered in the donut chuck and ready to have the bottom finished. Hope this helps Dan.
 
Some of the vendors also call them chuck reversing adaptor. I dont have one yet, but Bernie has me talked into buying one when the funds are available. It sounds like a real time saver.
 
Thanks for the feedback guys ... even bringing in the tailstock temporarily and lining it up with the center really helps. Not sure why I didn't think of that ... but i guess it's all part of the learning process.
 
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