topic Re: How to create joints so that a ball just rests in a cylindrical hole in Fusion Design, Validate & Document Forum

How to create joints so that a ball just rests in a cylindrical hole

j.camm — Fri, 21 Jun 2019 15:59:55 GMT

I have a disk with a hole in it. I have a spherical ball whose diameter is larger than the diameter of the hole. How do I create joints so that the ball just sits on the hole, as if under gravity with the hole axis vertical, so there is a circular line contact between them with no interference? What if the ball is not spherical but has a general axisymmetric curved surface? I've done it roughly by eye in the section view but obviously that's no good.

Thanks in advance.

Re: How to create joints so that a ball just rests in a cylindrical hole

laughingcreek — Fri, 21 Jun 2019 16:59:53 GMT

here's 2 possibilities, the first with a slider joint and contact sets, the second with a rigid joint and a sketch in the sphere component to anchor the joint to.

Re: How to create joints so that a ball just rests in a cylindrical hole

j.camm — Mon, 24 Jun 2019 08:54:21 GMT

That's great many thanks. I did not really understand Contact Sets but this helps with that too.

So as I see it, using the slider joint then the Contact Set between the two pieces gets the ball to rest in the position I want it but remains movable upwards. So using that position to make the sketch then finally anchors it fixed, if desired.

Re: How to create joints so that a ball just rests in a cylindrical hole

laughingcreek — Mon, 24 Jun 2019 16:29:13 GMT

If you know the diameter of the hole, you shouldn't need to preplace the sphere in order to figure out the sketch for the joint location. that would be over complicating things.