Attached is a simple concept model based on the SimMechanics' Crane example. I have a platform moving vertically. On top of it is attached another body (mushroom), connected via a prismatic joint. The mushroom has a certain mass. Is it possible to compensate for the gravity force exerted by the mushroom on the platform, such that when the platform is moving, the mushroom is moving too (diregarding the dynamic effects)?
I tried adding a constant (force) equal to the mushroom weight, via a joint actuator, but without success. Notice there is a soft spring with an end-stop. Without the gravity-force compensation, I run into the end stops. Adding damping will help, of course, but is besides the point.
The model is implemented in the obsolete SimMechanics. A solution in SimScape is accepted as well.