Sympy physics mechanics: Speed constraints / implied forces

[Peter Stahlecker]

I was playing around with a simple 2D  pedulum consisting of 4 bodies.

I included one non-holonomic constraint on one of the rotational speeds.

I also wanted to calculate the forces acting on the support of the pendulum, using 

KM.auxiliary_eqs.

Now the ‚virtual speeds‘ needed to calculate the forces appeared in forces, calculated as usual forces = KM.forcing_full. Also their time derivatives appeared

When I removed the speed constraint, the virtual forces and their time derivatives disappeared.

As the support by definition does not move, I simply set these virtual speed equal to zero.

Is this correct, or how can I handle this situation properly?

Thanks for any help!!