Da Vinci was a genius

He designed many types of perpetual motion machines. They all are based on the principle that one weight is farther from the center than the opposite weight (see drawing) which causes the rotation.
https://www.thingiverse.com/thing:2791609
https://www.thingiverse.com/thing:2800940
https://www.thingiverse.com/thing:2833419

This Thing requires a good understanding of the Major Laws of Physics :-)
The design in this Thing can be printed without supports or rafts.
Standard 17 mm glass marbl