Each PCDU has two motors. The drum motor drives drum and the development motor drives development unit. For details about development drive, see Development Unit Drive.
Each color drum has a drum motor [A], and the drum is driven by the drum motor through gears. The development unit has a different motor, to remove fluctuations in load in order to improve the precision of color registration.
Two encoder sensors [C] monitor the rotation of the encoder wheel [B] and the signals are fed back to the drum motor to control the motor speed.
Only Pro C5200S/C5210S has the drum home position sensor [D] which detects drum home position using an actuator.