Actualy, Johnson Motors will make them in any configuration you want. 1/4" axle,6 or 5mm axle, 6600rpm@12V or 18000rpm@18V, as long it's in their datasheets they will redo them.

Only 1 problem. Minimum order 10 000.
And that's the reason Graupner is running out of the 6mm axle 6600rpm hi torque version. Their supply is gone, and with brushless taking over hand over fist, more power for less cost, why would a firm invest in old school tech?

Most of the clones we find on Ebay are from simular situations. Overstock/misplaced stock from leafblowers, automated car sunroof setups and so on.

Other clones are "real clones" , Chinese or simular, about the same size of housing, less copper windings and no quality control.