Triple Gear Crank Fidget
A 144 mm desk plate with three real meshing gears — a 24-tooth crank wheel with a domed finger knob driving two 14-tooth pinions, all captured on mushroom-cap posts. Prints fully assembled, no supports: four separate pieces, 0.45 mm clearance everywhere, spin the knob and the whole train turns.
mechanism gear-train fidget print-in-place