Recover energy from gravity

[rc4]

I understood where come from the problem, it's only when red object has a torque (around itself) from green object. Last scenes, red object is not perfectly perpendicular because Algodoo change the position of red object (need to zoom a lot for show it). It's possible with red object to give at green object 0 torque (2 torques cancel themselves), the same is done at red object but like position of gravity (and trajectory) are not the same the red object has a torque if forces are not perpendicular. This torque create energy. If you look at slope of trajectories of center of gravity, it's logical: there is a phase angle between object red and object green.

[rc4]

bad scene

[rc4]

With this scene it's possible to have an oscillation for energy. This oscillation decrease with frequency but never diseapear.

[rc4]

In this last scene I can recover 1.3 % at frequency 12000 Hz. If it's an error of Algodoo it's 0.25 J of 18 J at this frequency and with stable forces I don't think it's possible. Someone else can test with another software ?

[rc4]

New scene. Explanation where the energy come from.