Robot doesn't fall straight

edit

It looks like there might be some parameters not well set. I recommend you visually introspect your model to detect what's wrong:

1. Right-click it and choose View -> Center of Mass - the way it wobbles in the end suggests the center of mass may be hanging under the ground
2. View -> Inertia - the pink inertia boxes should be close to the size of each link
3. View -> Collisions - the orange collisions should also be close to the link sizes
4. On the top menu, choose View -> Contacts - the blue dots will show you when things are in contact

Hope that helps spot the errors!