Circle intersecting sphere

[[Jo...]]

Hi,

What is the best way in Calypso to put a theoretical diameter onto a measured sphere when reporting a gage distance. Think 2 spheres end to end on a shaft, and a distance callout using gage diameters to slice those spheres. This can be done on cones obviously with cone calculations but was looking for best method with spheres.

Thanks!

[[Jo...]]

For the time being, i opened two cone features and recalled the sphere points into them. I used cone calculations with the given gage diameter and it did give me a plausible distance result. Probably not correct though..... 🙄

[[Ky...]]

Hello Joe,

Very interesting question. I can't think of a direct way in CALYPSO to do it. I don't know of a sphere equivalent of cone calculations (probably because there isn't an easily defined axis like there is in a cone), but we can definitely do it with formulas.

First step I would do is make a secondary alignment. From what I read, I would use your "shaft" as the spatial feature (or maybe a 3D line between the two spheres) and point that in the Z direction (might be a different orientation, but for now assume Z), and then use one of the spheres as your X,Y,Z origin (planar rotation shouldn't be necessary).

Next what we need is the distance between the center of the sphere and where that gauge diameter is. This should be something like h=sin(arccos(r/ρ)) where h is the height difference between the center of the sphere and the gauge diameter, r is the gauge diameter and ρ is the diameter of the sphere. I'm going to try to attach a paint drawing that might make this formula more obvious (I'll apologize now for subjecting you to my drawing skills)
.

Now you can just make a point (or circle), set the Z (or whatever direction you are using for that axis) to the formula above and the other coordinates to 0 (using the alignment we made before). Repeat this for the other side and then get a distance.

Hopefully this helps, or at least gets you on the right path.

[[Jo...]]

Kyle,

Thanks for the idea. I'll give it a whirl..

[[Da...]]

I'm a little confused. This should be easy using cylinders intersecting the spheres. Construct a cylinder with the right diameter and in the right direction and let them intersect.

[[Ky...]]

Hello Daniel,

This also seems to work based on my testing. Might be a bit easier if the user isn't very comfortable with formulas. I, however, need to use my math degree somewhere. 🙂

[[To...]]

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You wear your nerd badge proudly.....

[[Da...]]

2023 version has a Special feature, "Circle on a Sphere" it's in features/ special features. Not sure how it's used but might help.

[[Ri...]]

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This is also in 2022, but I have been unable to get the correct result although it visually looks correct on screen, and the nominal is correct.