Wednesday, 26 January 2011

Off center turning.

Last night at our woodturning club meeting we had a demo by Chris Pouncy from Robert Sorby.
One of the things Chris demonstrated for us was the Robert Sorby Wobble chuck.
At about £50  00  I think it is very well engineered and good value.
But it is not the only way to do it here is another way.
I have not gone to a Lott of trouble with this as I am a bit pushed for time.
This shows you the way it can be done quite simply.
It can be done this way to create anything from off center goblets to Finials ,Box lids you just need a few scraps off wood to have a play.


The first thing I did was take a bit of Yew branch and rough it down with a spindle roughing roughing gouge,

                                                      Click on pics to make them bigger.

The next thing we need to do is turn a ball on the end which has to fit a set of gripper jaws.
It is essential that you use gripper jaws for this as there is quite a bit of lateral pressure.
The ball has to be a reasonable fit.




The next important thing when you have placed the piece in the jaws is to mark the ball against the jaws with a pencil so that you will be able to return to your original position if required.


Now trim the piece with your spindle roughing gouge ready to off set.
I have set this to the maximum possible off set and brought up the tailstock for the first cut.

This is now ready to turn down very carefully with a spindle gouge taking very fine cuts.



I have now moved the tailstock away and this bit is ready for sanding.
I have used a sanding pad for safety.



If you are worried about sanding when the piece is spinning stop the lathe and do it by hand.
Then I moved the piece in the jaws to the opposite extreme for the next cut.


I have now returned the piece to its original position the pencil lines have made this easy.
It is now parted off as a lid for a box.


Here we have the finished piece it probably took about 15 minutes and was very simple to do.
This is a very simple design because I only did it to show how easy it is.
It would be no harder if it was more complicated.


A couple of important safety points when doing off center turning.

Always wear a full face mask as there is a greater risk of getting a catch and the piece flying off the lathe than with normal spindle turning.
Every time you re Aline the piece make sure it is clear of the tool rest.
Take very fine cute to help avoid getting a catch.

4 comments:

  1. So that's how it's done. Great blog, George.

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  2. Hi George

    Good to see you keeping up with the blog. It is good to see so many useful techniques for people. Interesting too.

    Keep it going.

    Take care

    Mark

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  3. Hi G,

    Is this the technique you used when you made your smaller bird sculpture?

    Very effective indeed and a valuable technique.

    Cheers,

    Lee.

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  4. Thanks for the comments.
    No Lee when i did the smaller bird sculpture it was all done between centres.

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