My New Sphere Jig

[David E. Nelson]

Last weekend I was at the library and picked up Woodturning Wizardry by David Springett. I was absolutely amazed and inspired. My turning skills aren't advanced enough to pull off the hollow forms that David describes, but I thought that I could probably successfully tackle the Singapore Ball. I have never turned a sphere before but it sounded like a good project.

This weekend was rainy so I didn't get out to find an appropriate piece of wood so I decided to make a sphere jig. I looked around on the web and found a couple of examples that I used as design guides. I set off to cutting, drilling, and grinding and by the end of the day I had a pretty respectible jig. It is made out of staneless and mild steel. I had to buy a few bolts and a thread tap, so I only have about $12 dollars invested into the project. Hopefuly my Singapore Ball will come out as good as the jig.

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[David E Keller]

Nice job on the rig. I've not seen one in action, so I think a photo tutorial is now mandatory.:D

Looking forward to seeing some spheres.

[Baxter Smith]

Looks good. Will second the request for action shots!:D

[Steve Schlumpf]

David - Welcome to the Creek! Looking forward to seeing the sphere!

[John Keeton]

I am duly impressed with the build, but terribly unsure about how this thing works!! A pic tutorial is a must!

[Rob Cunningham]

Nice looking jig. Looking forward to seeing the sphere.
What's the pointed threaded stud for in the second picture?

[Thom Sturgill]

http://www.youtube.com/watch?v=gNCT7Yu-oRc&feature=PlayList&p=9D02B3D6E3928EB6&playnext=1&playnext_from=PL&index=17

What this does not show, is cleaning the nubs off the ends. That is done using jamb chucks and the pointed centering post registers in the hole left by the live center so that the ball sets true to the jig when re-mounted.

[Mauricio Ulloa]

Very nice jig! Please send some pics and videos of the process and the results!

[Bernie Weishapl]

I agree that the jig looks good. Please post some pics of it in use and the final results.

[Brian Kent]

Just watched the u-tube. O Wow.:eek:

In lapidary work you have a rock supported on the end of 2 rotating steel tubes.
http://www.polcirkelsten.com/eng/Spheres-how.htm

I was looking for something like that for wood, but this makes so much more sense for wood.

[David E. Nelson]

The original intent of the pointed stud was to help with centering the point of rotation in the headstock / tailstock axis as well as the side to side axis. However, Thom Sturgill's post points out a third usage that I hadn't considered. This should be another use that will help with accuracy. Thanks for the tip.

[bob edwards]

I agree, the jig look nice. I'd like to see a photo of the base showing how the jig mounts to the lathe. The jig must be secure and the cutter must swivel. How did you accomplish that? I'd also like to offer this suggestion. The cutter seems to be in the shape of a half round scraper. I think you will have better results with a pointed cutter. The less cutting surface you present to the wood the less vibration you will have. Look forwards to a demo!!

[David E. Nelson]

Bob,
Thanks for the feedback, I haven't even tried it out yet so I'm not sure about the vibration, but that makes complete sence. I will try to take some more pictures tonight to give a better overview of the component pieces and how they all fit togeather.