The motor is rated to 3V 2A, but from what I've read on many forms/sites they should be run higher, 12 - 24V even. Bad idea?
The onboard power is from the Arduino Uno, so that's at 3V .5mA. The Uno has the Ardunio Motor Shield on it: http://arduino.cc/en/Main/ArduinoMotorShieldR3
I've moved away from the onboard power since that's not going to get us enough torque. I'm got a cheapie 12V 1A power supply connected to the terminals on the Motor Shiled (Vin, Gnd). And I cut the power jumper under the Vin pin on the side of the board.
Everything runs nice an cool, the shield and motor are both room temp.
I found through trial and error that putting a resistor on one lead per each channel that drives the coils that I no longer get power feedback into the board. I was using 200 ohm resistors since those were handy. The stepper works great now. However it's really weak, very little torque.
I've tried balancing the circuit as best possible - or so I think.
Attempting the little circuitry knowledge that I remember: Voltage * Amperage = Resistance
12v * 1a = 12 ohm resistor. (Correct?) I've got a 10 ohm on it now (just roll with it) and the motor is still not strong enough. Is there anything that I could improve upon? Or is this about the limit?