I am developing a wheel-based crane model.
Recently I experimented with its wheels, modeled as NxWheelShapes.
Both angle and motor torque worked quite well. However, when I tried to apply nonzero brake torque (with zero motor torque), instead of staying in one place, model started jerking back and forward. Sudden jerk in one direction, gradual slowdown, and when it is stationary - jerk backwards, and so on.
Brake torque was the only thing changed.
I would really appreciate some ideas about what is going on.