A while back, there was a lot of Astrosyn 7.5 deg. stepper motors on ebay. I bought 6 just to play with. The specs are: Model 28BB-H151-11, 5 Volts, 3.6 Ohm coils, 7.5 degree step. The base is bigger than a NEMA 23, but smaller than NEMA 34. I may now have a use for motors with a big step. Has anyone used these motors? If so, how do they work for you? What is the wiring pinout? They have 2 coils, each with a black, grey, red and yellow wires.

Thanks,
John