Unstability of spherical joint

I am a beginner in simscape multibody. I want to use spherical joint with zero friction to simulate half sphere air bearing with equally distributed masses on it. When I simulate my model, it stays stable, but after 3 seconds it falls. Only force applied is constant gravity force. Do you have any ideas?

Answer 1

[Steve Miller]

Without your model, it is difficult to give you specific advice.

If "fails" means that the spherical joint starts moving due to gravity and you expect it to not move, it may be that your step size is too large. Try reducing the maximum step size by a factor of 10 or 100. You can find that on the Solver Configuration Panel, Solver pane.

--Steve