The original system employed the use of the Greartisan 12V brushed motor rated at 100rpm. The system was designed to have an input crank link with a D-shaft cutout matching the motor shaft's cross section profile itself.
The motor is rated at 12V and 1.1A, and so the theoretical max power is given by P = VI, or about 13.2W. At 100rpm, by using the relation of P = Tω and rearranging, the no load motor torque at 100rpm is 1.2605 Nm. The images below describe the motor visually and by specification..
Greartisan 12V brushed motor image and specifications
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