http://www.andymark.com/product-p/am-2062.htm
This part links the PG71 gearbox to 500 series motors, such as the 9015 motor.
EDIT: somewhat irrelevant, but has anybody else noticed that the 9015 is made by Chiaphua Components Limited (CCL), the parent company of CCL Industrial Motors (
CIM)
EDIT 2: no, that is not a coincidence, that is the same company that makes FRC's staple drive motors.