might actually just order the 13h from ebay, found a few around $5 Spec summary for all the nidecs belowby MR_T - General
Quotematthock Progress report: 75:1 Pololu motor experiment has thus far failed. Not enough torque - it can run the filament in an aggressive extrude/retract cycle without the hot end for ages without the heat problem with the fan mounted on there, but once you add the hot end, it stalls. Part of it may be the geometry. When I shifted the motors to the inside of the filament paths, I think it mby MR_T - General