Hello maoam

Welcome to Sm.

Just out of curiosity, you said your machine is driven by wind, correct?

Are you are trying to achieve a basic windmill-type of animation or?

I ask because after doing some quick research on Piezo Electronics, it looks like it works more on vibration or impact rather than a brushless-motor-type of generator?

Do you have a picture you could show us of your model, and what you would like it to do, as I really don't think a full-on dynamic simulation is needed here if all you wish to do is to see it moving

...plus, it will render much faster without all of the calulatory overhead

Thanks!