internal tenon?

[mattyts]

Hi all,is it possible to use an internal tenon and external dovetail jaws on my chuck to hold a workpiece(bowl) any details on how would be appreciated
Thanks

 

[Silverbirch]

Not sure exactly what you mean by an internal tenon. Do you mean a recess in the bottom of a bowl, for example, where the jaws expand into the recess and grip it securely?
If the jaws have a dovetail profile on the outside, hollow a recess of a suitable diameter, a little deeper than the depth of jaws to enable them to expand into it and have the shoulder sit on the outside edge of the recess. The recess will need to be given a dovetail profile too, to match that of the jaws. A few more details about exactly what you are trying to do, what kind of chuck and jaws you have etc would help us to answer your question.

Ian

 

[mattyts]

Hi silver,yeah,i mean a reccess to grip the bowl i just didnt know the name for it,lol.
I have an axminister k10 with C type jaws

 

[Silverbirch]

You`re too quick! I edited my post, just after posting (see above), but you`d already replied!
Hope what I`ve written makes sense now.

Ian

 

[mattyts]

I just wanted to know how to get that dovetail profile to prevent the workpiece moving

 

[sammo]

Hi
This YouTube link https://www.youtube.com/watch?v=PzG70rAJRIQ --- goes into some detail about the pro's and con's of using your chuck in expansion mode

Chris

 

[Silverbirch]

P.S. Many turners would suggest that a tenon which the jaws close onto, gives a better grip than a recess which the jaws expand into.

Ian

 

[mattyts]

As I dont have a way of finishing the bottom of a bowl just yet,I'm planning on using a recess to turn them so i can finish and display the bowls while still having the opportunity to finish the bottom when I get the facilities to do so,hope this makes sense.

 

[Brianp]

Have you tried a jam chuck? You turn a piece of scrap timber so that the head side fits the chuck and the tail side then matches the interior of the bowl. Bit of paper towel between the jam chuck and the bowl then bring the tailstock back up to the centre of the bowl's underside at which point you can carefully turn away the tenon or otherwise clean up the bottom.

Keep the speed down and the cuts light, and towards the headstock as much as possible. If you're careful you'll be left with a reasonably small nib that you can just carve away, or with your chuck recess, a neater edge.

Hope that makes sense...

Brian.

 

[monkeybiter]

i think that dovetail profile is less of a requirement than is often assumed, wood is easily compressible and if you create a parallel tenon or recess then when tightened up your jaws will compress the wood and create their own best tight fit.
Always re-check the tightness periodically.

 

[YewTube]

I just wanted to know how to get that dovetail profile to prevent the workpiece moving

Put a skew chisel flat on the rest and use the point as an angled scraper.

Bill

 

[finneyb]

As I dont have a way of finishing the bottom of a bowl just yet,

Oh yes you do !!!

See the Wyomingwoodturner http://www.youtube.com/watch?v=Vdn0PdySkh4 I do like his videos, once you get used to his pace.

Brian

 

[CHJ]

There is an image of cutting a dovetail socket with a skew in this WIP