if you into mechanical engineering, the helicopter rotor must be the most fascinating thing. note, each blade can tilt independently, coherently to position, while spinning at 8 turns per sec. you thought rubik cube is ingenuous.
helicopter rotor. that disk at bottom and the verticle bar is so that it can tilt the pitch of the blade at exact pitch in every position of the blade as it turns
this, you buy. real rotor. (not fixed pitch) powered by battery. i've seen gas powered ones with much complex rotor
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