Lately I have been spending some time creating assemblies that are able to lift from or rotate on a floor.
For this I use cam connection with the "liftoff" option activated. After a lot of simulating with cams that didnt seem to work, i found out you should only start your simulation when the model is fully regenerated (green light), only after that the cams will do what they should.
Another tip: if you see your mechanism going bad during simulation, you should press the red "terminate" button at the bottom of the screen a few times, and it will actually stop.
A question: when should u use cam-connection and when 3d-contacts?
Ps. the learning curve of creating mechanism is ridiculous: there are too many windows to go trough before you can play-back the simulation. And you cant group simulations to get a cleaner interface .