From ancient times, people have been trying to find out the perfect energy producing machine. For that purpose, brilliant minds put themselves to work and researched the most sophisticated mechanical machines ever. Until nowadays, no such machines have broken through the filter of time, and no such wonderful inventors are known to have made the over unity device.
All I know is that there is no smoke without fire, and there are a lot of non-interested people claiming the same thing.
For example, this man from Serbia, Veljko Milkovic, appears to have invented a device that does overunity: it outputs more energy than inputted, apparently violating Newton’s Third Law of Motion: “For every action there is an equal and opposite reaction.”
It seems Veljko’s machine uses the gravitational force for its power source, thing that others have also claimed.
“This gravity machine has only two main parts: a massive lever and a pendulum. The interaction of the two-stage lever multiplies input energy into output energy convenient for useful work (mechanical hammer, press, pump, transmission, electric generator…).”