Remount Rough Turned

[Erwin Nistler]

I have a large bowl I rough turned a year ago. Now the tennon for mounting the chuck is nearly 1/2 inch out of round. This is a heavy, 12" bowl with an uneaven top. How am I to true up the tennon to remount the bowl????

 

[Mark Mandell]

Spread the jaws on your chuck to full open.

Place the bowl over the chuck and bring the tail stock up to hold it with the point in the center of the tenon. Apply pressure with the TS and turn the piece by hand to check centering; adjust if necessary. You are now using your jawed chuck as a jam chuck.

Set your tool rest up so that you can work the tenon, apply strong pressure with the TS, and with your parting tool, recut the tenon back to perfect round.

You're now good to go for mounting the tenon in the chuck jaws for final turning of the bowl.

 

[C Edward Moore]

If you have a large chuck for a vacuum system you can use it instead of a jawed chuck as the jam chuck. Like Mark has written, apply plenty of pressure with the tailstock once you have it centered as best you can.

I have found that taking only a 1/16th of an inch width at a time with the parting tool works well for me. Once it is round, wider light cuts are fine. You may find that shearing cuts across the bottom of the tenon with your bowl gouge are necessary to flatten the tenon. Flatten it and leave a small tenon near the tailstock point that won't interfere with the jaws of the chuck. Leave this small tenon so that you can reverse chuck again later.

You will probably find that the bottom of the bowl near the tenon is warped as well. You must deal with this if the jaws of the chuck will seat against the bottom.

 

[Bruceyp]

And Go Slooow!!

Make sure that your speed is as slow as you can get it and stand back the first time you power up.

 

[john lucas]

Mount a scrap piece in your chuck and make jam chuck to fit inside the bowl. Put the tailstock live center on the tenon gently. Rotate the bowl by had and move the center until you get the bowl and tenon aligned the way you want. Now gently return the tenon to fit the chuck.
When I didn't own a chuck I would turn oval tenons down to fit a hole turned in a waste block on my faceplate. Same idea

 

[Stacey S]

Another option with the jam chuck. Make sure that when you are rough turning the outside of the bowl and still turning between centers. When you turn the tennon for the chuck, make sure you leave a nipple on the tennon where the live center held it between centers so that once you have hollowed out the bowl and reverse chuck it with the jam chuck and bring the center back up place the center in the same location as it was before( this is already marked because you left the nipple) and tighten up the tail stock. This will basiclly make the setup self centering. I learned this last weekend with a day long class with Nick Cook and it has worked well for me. Good luck with whatever method you try though.

Stacey

 

[Bob Edwards]

This may not help with this bowl but I would like to share my method for turniung a bowl. I start between centers and use a live "cup" center in the tail stock. I always turn the bottom first leaving the spogot for the scroll chuck as well as the impression of the cup center. I than reverse the bowl and grab it with the scroll chuck on the spogot. Once the inside is shaped I can reverse it again to redo the bottom. At this point I use a "jam chuck" with a piece of dense foam as a pad that fits into the bottom of the bowl. The impression left by the cup center allows me to relocate the center easily. This method works well for all bowls but especialy for natural edge ones. The small nub left that was the impression of the cup center can be worked off by hand with a small knife and hand sanded. The attached was done using this method. Hope this makes sense.
Have a Happy
Bob Edwards, San Antonio

 

[Erwin Nistler]

Thanks Y"all. After I read this over again I should be ready to go at it.

 

[Barbara Gill]

What I have started doing with rough turned bowls is leaving a dimple in the center of the inside of the bowl. The cup center has already marked the center of the tenon. Then when the bowl is dry I use the inside center mark to place it on my spur chuck and the center mark on the tenon to relocate to the tailstock. I then round up the tenon and chuck it up in the Stronghold.Since I hold the spur center in my Stronghold, so far depth has not been an issue.

 

[dkulze]

you can also leave a spike of wood up the center of the bowl when you rough turn it between centers. This allows a remount that will always be centered (unless you are turning a piece angled to the grain).

dk

 

[Mort]

A huge THANK YOU to Bob Edwards for that dense foam idea. I tried and like it.