Domino piece slanted

Hi everyone,

I'm trying to build a domino track, so that you drop the first piece and it produces a chain reaction. However, I noticed that sometimes pieces would fall on its own. The problem seems to be that even if I place them completely vertical, they have a small rotation.

This is very easy to repro from scratch:

1. Add a plane in 0,0,0

2. Add a cube of dimensions 0.1, 0.1, 0.01 placed floor level (0, 0.05, 0), with a rigid body
   

Initially the rotation is 0, but when it starts then the rotation is for example (-1.3, 0.016, 0). Sometimes is enough to tip pieces over.

Why is that? is there a numerical error? am I missing something?

I've tried all this so far, I'm running out of ideas:

• Changing the depth, of course deeper is more stable, but then it's harder to tip them off, so it's not really a solution for what I want to do.

• Changing drag and angular drag doesn't seem to change anything

• In play mode, reset the rotation to 0 to check if it was an initial micro-collition with the floor, still it gets tipped over

• Played with moving a bit the center of mass, I can balance a bit better but doesn't really solve it.

• I used Sleep on the pieces, that made it much better, but they're still tipping of sometimes before getting hit, I don't understand how that's happening.

Any other ideas?

Thanks!