Created in order to temporarily use 28BYJ-48 in place of real NEMA 17 motor to move Z axis in http://www.thingiverse.com/thing:560343. It fits nicely to small cheap 28BYJ-48 stepper and has exact diameter and same mount holes of NEMA 17 motor.
UPDATE: it is proven that this motor has enough power to drive Z axis on Funbot i1 (http://www.thingiverse.com/thing:560343) but maximum Z speed i've acheived without loosing steps is around 1mm/s with very low acceleration setting. Its performance is so poor that I will not recommend it for any use in this printer.
Printed with PLA, 2 perimeters, 25% infill.
I also uploaded .fcsd version to modify.
Attention: 28BYJ-48 stepper motor has extremly poor overall performance in comparision to even small NEMA17 motors. It has not enough power to drive any extruder. If you turn up amperage on stepstick to drive more current than this motor can handle it will heat up quickly and burn or melt this adapter and possibly other elements.
FreeCAD Linux 0.17