Please note that for a fast turning electric motor, 1400 to 1700 rpm, it will be necessary to use two motorisation kits, as two belts are required to reduce the motor speed to somewhere between 50 and 80 rpm as a practical milling speed. See photo.
To use a bike to manually turn the mill, the kit above is not required, you could use all bike parts, a large sprocket wheel on the mill and two small sprocket wheels on the rear axle, one for the pedal drive and one to connect to the mill by means of a second bike chain, length to suit, see picture in link below.