[DonRotolo]

Indeed. Remember, the big gear inside that motor housing is plastic - it will likely break before those black plastic couplers from the KoP would.

That being said, one think we have done in the past is to 'drill' out a metal bar (tube) just big enough so it fits over the motor output gear, and then use a setscrew to hold it onto the gear. If you are careful, it doesn't wobble much.