Thank you for all the things that you are sending me  ;)

I don't know miss something in my exercise but i thing i'm really close, know the satellite turn, but in one moment disappear.

I attach all the things that i have, all the information about the exercise, like this may be your answer are completily usefull for me.

1 I attach the picture of the thing that should turn, this object should have one move of rotation. Have two views but the simulation shuold be in 2D.

2 I attach the ecuations with that should have this object (satellite).

3 I attach my .xml

4  Is a control system the angle "?" of an axis of a satellite using a rotating wheel. To vary the angular velocity of the satellite "?" changes the angular velocity of the wheel "v" by a motor located in the satellite.

    (? = v - ?) both are angular velocity.
    B = 1,01.10[sup]-6[/sup] ( viscous friction coefficient.
    J1 = 13,6 kg.m[sup]2[/sup] moment of inertia of the satellite
    J2 = 13,6.10[sup]-4[/sup] kg.m[sup]2[/sup] moment of inertia of the flywheel.
    Je equivalent moment of inertia.
    T torque developed by the motor.