5 mm Shaft Shear-Pin Breakaway Hub
This print-in-place breakaway coupler works like a snowblower shear bolt or the sacrificial gear in a blender. A 5 mm motor shaft drives an inner hub, which is clamped by an M3 set screw over a captured nut. Two cross pins cut from 1.75 mm filament lock the hub to a 44 mm output flange with four M3 holes on a 36 mm circle. On a jam the pins shear instead of the motor or gearbox. To reset, push the stubs out and insert two new 15 mm snips of filament.
mechanism shear-pin torque-limiter 5mm-shaft