How to rotate a rigidbody that has hinge?

Hi,

Apologies if this is not the correct place to ask for some advice on this question, hopefully I could ask for your help with this:

How to rotate a object with rigidbody and hinge?

I have a gameobject with rigidbody and hinge(y axis pivot), on that a child also with rigidbody and hinge (other axis such as x), no forces are being applied to either e.g. via script.

I have tried with this type of syntax:
transform.RotateAround(…)
transform.localEulerAngles = Vector3(…)
rigidbody.rotation = Quaternion.LookRotation(…)
Making animations on the transform…

But these do not yet seem to have any effect.

I read about rigidbody.MoveRotation, which should be used to rotate rigidbodies but soar can understand how to code this, I tried:
var deltaRotation : Quaternion = Quaternion.Euler (new Vector3 (0, 20, 0));
rigidbody.MoveRotation (transform.rotation * deltaRotation);

Can I ask if this code looks to be correct to rotate this type of object on the y axis?

Disable MeshRenderer and parent GameObject clone(no rigidbody, no hinge), and rotate or move it.

Interesting idea, many thanks for that!