I have an issue that turned up after installing my stepper motor. Please take a look at this Youtube link.
[ame=http://www.youtube.com/watch?v=TLXR9X7TLq8]WhyThis - YouTube[/ame]
The stepper motor that I am using is a 57BYG, 1.8 degree 12V running at 30 V, 4 phase, 0.6A per phase, inductance per phase 25mH, 100Mohm, class B, rotor inertia 38gcm2, hold torque 6Kg.cm, mass 0.65kg