ball in box howdedodat?

Frank Fusco

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The president of our woodturning club is a very clever guy and good turner. He is former rocket engineer and has unique visual abilities that translate into work that comes off his lathe.
This item was at our last show and tell. I haven't a clue how he did it. Many of us examined the box closely, there are no glued up bandsaw joints anywhere. He turned it all. The ball is as perfectly round as the eye can detect. Unfortunately, he did not do a series of in progress pictures.
 

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I too have seen how to do this once, but :huh: can't remember where it was to tell you how to do it. If I remember correctly, it is a series of drilling with the correct bits. Will look at one of my puzzle books tonight and see if I can find it. It is cool and the finished ball inside the box is a lot of work if sanded and finished.
 
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My guess is that one starts with a cube within a cube. When the inner cube is free to rotate then you mount it between centers and start to round it off one side at a time with the outer cube free running around the inner cube. You probably have to nock off the corners of the inner cube before you even start using something like a file.
 
My take: Cut a cube. Using a hole saw, drill a hole in each of three adjacent sides. The hole needs to be about the right size for your lathe chuck.

Mount the cube on your lathe, using one of the sawn holes to mount it.

Turn the opposite (tailstock) end, beginning with a hole & forming a dome inside the hole.

Rotate the blank 180 degrees, remounting it on the chuck, and repeat for the opposite end.

Rotate the blank 90 degrees, chucking a sawn hole, repeat the hollowing/doming. This time your dome should intersect with both of the previous domes.

Rotate 180, repeat.

Rotate 90, mount in sawn hole, repeat hollowing/doming. THIS dome should intersect with FOUR previous domes. Refine the intersections, shape the domes together into a sphere suspended at the chuck.

Last... rotate 180 and CAREFULLY form the last dome, shaping it to very closely conform to the sphere before you part it off.

When it's parted off, it'll be a good sphere lacking a little refinement, sanding, finishing. Mount the sphere alone between cup centers to do the refining work while you hold the cube out of the way with wires, your fingers, whatever it takes.
 
I read an article about making these a few years ago, and if memory serves correctly, Tim has described the process pretty closely.
 
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