.....at : https://youtu.be/_QLEERYS5C8 (https://youtu.be/_QLEERYS5C8)
Some topics of our forum (see "heavy hub lever " and "heavy hub inverted pendulum " ) are related to this elementary manner to store motion and use it as a mechanical "battery".
Any kind of oscillator (electrical, mechanical) needs a supply (battery,flywheel )...thinking about a possible gravity powered "device" as a double/,triple mechanical oscillator.
Al_ex