Problem with external torques on simscape multibody.

Greeting

I have a problem with the attached mechanism.

Indeed when I apply a resistant torque in joint 1 and an equivalent but opposite internal toque in the same joint there is no motion which is correct,

I tried to check the same approach on the other joints but it does not work

Joint 2 : couldn´t immoblise the joint by applying an equivalent and opposite external torque.

In joint 3: I could not make the mechanism move by applying an external torque. the only thing to make it work was the internal torque on the joint,

Thank you

Best regards

Answer 1

[Steve Miller]

Hi Amatoallah - you need to make sure the external torque is applied about the z-axis, not x-axis.

You have it correct for "Revolute " but incorrect for "Revolute Joint1". See screenshot below.

If the torque is applied about the x-axis, it has no effect on this planar mechanism.

--Steve