Algodoo

it balances itself but idk how to make it find the center of an object...

It's a lot simpler than it looks. There's a small but ridiculously dense invisible circle in the bottom.

lol, that's just because it needs that counter weight. As long as the object your balancing is lighter than the machine, you don't need that. Just modify it if you like, based on your objects weight needs

That super-dense ball is the only part of the apparatus that does anything for balance. All the other crap doesn't make a bit of difference. If I remove it and tilt the thing, it falls over. I can remove everything else not structurally necessary (including the half-rings that look like they're supposed to do something), and it works perfectly.