How to make a model about Simple pendulum

If i have a AnySegment .It has Mass, Jii and two AnyRefNode on it , And there is a RevolutJoint, and the Gravity is right .Why when run
the model ,I can’t see the movement about Simple pendulum.


can you please explain that a little bitmore detailed. What AMS? AMMR? Model? What did you change to the model?