Recover energy from gravity

[rc4]

If blue object turn at constant rotational velocity around axis "axis" (external system not drawn limit its rotational velocity). Orange object is forced to be like image because there is Fc force. If I apply forces F1 and F2 on orange object, it will turn and I increase potential energy. But in the same time blue object has a torque from -F1/-F2 because distances d1 and d2 are not equal. The energy from blue object can be recover by external system and limit rotational velocity of blue object. With a rotational velocity clockwise, orange object can receive a standard torque. F1/F2 on orange object will slow down orange object and decrease potential energy but this energy can be recover in the same time.

[rc4]

With Algodoo it's works, until torque is apply to small disk, the big disk receive a torque too.

If you change the direction of rotational velocity of big disk this change the sum of energy. If I compute energy from motor, this is less than the additional energy giving to the system.

[rc4]

I tested with Algodoo. The motor give 0.15 Nm * 9 rd/s = 1.35 J each second (in fact less because I take the last rotational velocity not the mean). Algodoo give 2 J, look at the scene please.

Another test:

rotational velocity at start of big object = -6.28 rd/s

rotational velocity at start of small object = 6.28 rd/s
rotational velocity at end of small object = 7.77 rd/s

energy at start for all system = 114.56 J
energy at end for all system = 116.408 J

Motor torque  = 0.15 Nm

Loss without motor for all system at 6.28 rd/s = 0.1 W

Power from motor = (7.77+6.28)/2*0.15 = 1.05 W

Power from Algodoo = (116.408-114.56)/1 + 0.1 = 1.95 W

Near the double because when torque is giving to small object the big receive the same free. Why not exactly the double ? because small object increase its rotational velocity at 7.77 rd/s but the big increase its rotational velocity to 6.34 rs/s  only. The energy is 0.946 W from the torque 0.15 Nm. So the result find by Algodoo is 1.95W and I must find 2 W !!! very close.

[rc4]

In the last post, maybe you can think the energy give by motor to big disk it's an energy from the motor, but not, the stator like the rotor turn around central axis and the motor don't turn really around central axis, it's not a true rotation because the rotor like the stator turn together.

I think it's important to take w1=-w2 like that motor "see" a real rotation for disk2. And it's necessary to recover torque give from motor to disk1 like that angular velocity around central axis is constant.

[rc4]

If I take stem and object at end like image shows. I give rotational velocity to stem around axis "x", object rotates around "x" not around "y". The system has less energy than if object turns around "y" too. Stem turns at w around "x", object turns around "x" at w, but don't turn around "y". Object and stem don't have same rotational velocity (w compare to 0). Now I can brake from stem to object, object add a torque (and I can recover energy from brake) to stem and add its rotational velocity, the system add energy.

I apply F3 to object, stem receive F1, axis "y" receive F2 and F4 ? so, all these torque cancel themselves but the system has more energy at end.

The system in this case seems to lost energy, but it's possible to give rotational velocity to object around axis "y" and accelerate the object around "y". At start all turn at w around "x" and object turns at w around "y". After, I accelerate rotational velocity of object around "y".

I think it's works only if moment of inertia are different for object and stem (around their axis), and it is I think. Energy giving by a torque is torque*angle, but like moment of inertia are different, angle will be different even torque are the same in value.