Auto-winding drum for weight-driven clock

This is a weight drum for a mechanical clock, incorporating an automatic winding system using a stepper motor and Ardunio. It allows a clock to be fully weight-driven and continue to run even while the weight is being wound by a motor.

The weight cord is wound around the outer drum, with torque transferred to the inner drum via a freewheel. The inner drum is geared to a separate escapement mechanism to power the clock. The motor sits inside the inner drum and engages a gear on the outer drum. During winding, the motor turns the outer drum relative to the inner drum, with torque now transferred to the inner drum via the motor instead of the freewheel. An external potentiometer measures the position of the outer drum to determine when to start and stop winding.

I used it to drive A26's triaxial tourbillon (https://www.thingiverse.com/thing:2761730), connected to my planetary clock (https://www.thingiverse.com/thing:4055592). Fair warning, the motor's maximum power is roughly equal