1. First, try turning the motor with your fingers, and notice how hard it is. Then, stick wires together in pairs. If the motor turns noticeable harder, you’ve found a pair.
2. To get the stepper just moving, polarity of each coil doesn’t matter, nor does it matter which coil is which. So make sure each pair of wires for a coil are together on one side of the plug (or the other side for the other coil), and plug it in.
3. To get the motor moving in the right direction, is actually does matter which coil is which and what the polarity of the coils are. However, if they’re wrong, the motor just turns the wrong way, it’s easy to fix that by swapping wires. Pick one of the following in order to reverse the stepper’s direction:
- Switching the polarity of either (one) coil, like changing ABCD to BACD or ABCD to ABDC.
- Swapping the coils, like changing ABCD to CDAB.
- Stepper direction can also be reversed in the firmware.
Most of the above is copied from: http://reprap.org/wiki/Stepper\_wiring
Let me know if any of that doesn’t make sense.
-Jesse