How do I draw, then cut a slice of a sphere?

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How do I draw, then cut a slice of a sphere?

Postby bill z » Thu Sep 14, 2017 4:29 pm

How do I draw, then cut a slice of a sphere?

I want to make a spherical plain bearing from wood, something that will be a section of a sphere, where the top would be 10mm above the center plain of the sphere and the bottom would be 10mm below the center plain. The attached picture will explain much better.

Since I only have 3 axes to work with, my plan was to use Aspire modeling to do half of the sphere, then turn the board over and use the same to cut the other side resulting in my desired sphere section.

I’ll also want to cut the outer piece (the casing) of the spherical plain bearing but with two pieces of wood sandwiched together to make it easier to assemble.

The problem that I am seeing right off is with the tools. If I use a 60° V bit the slope is more of an angle and not a sphere, plus, the cut near the center plain of the sphere is way off. If I use an end mill, I get similar problems but at the other end.

If you are wondering just how big this will be, the center hole will be 89mm in diameter and the height will be 40mm (just over 1.5 inches).

I am in need of some ideas.
spherical plain bearingjpg.png
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bill z
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Re: How do I draw, then cut a slice of a sphere?

Postby Rando » Sun Oct 22, 2017 11:28 pm


First, I think you're going to want to use NON-tapered ball end mills, since you'll never be able to get the truly vertical part right. If you're a brave god-like person, you might even try something called an undercutting end mill: ... s_192.aspx

You'd use the definition of a standard non-tapered ball mill, but you'd not have to worry about collisions nearly as much on the inside of the bores.

Does that help?


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