Question: Movable pulley dynamics

Hello, MaplePrimes!

I want to create a custom component to model dynamics of a movable pulley, which can rotate and move along some direction (translational motion). I’ve got dynamic system, which describes both motions of a pulley. Some information about this dynamic system:

 Variables x(t), coorda(t) and coordb(t) are translational coordinates, T(t), Tensa(t) and Tensb(t) are translational forces.

I’ve tried to solve a test with my custom component. But in some case MapleSim hasn’t solved this problem.

Problem 1. Good solution (a force is applied).

Model.

Result.

Problem 2. Bad solution (position is applied).

Model.

Result.

Further simplification…

(in dsolve/numeric/DAE/ix1reduce) system is inconsistent

Simulation failed.

Can anybody explain to me, what is the problem with my dynamic system? And what shall I do to solve Problem 2? How can I modify current dynamic system?

Thank you!