This stepper driver works well for me, on this link its $16.50: TB6560 3A Single-Axis Controller Stepper Motor Driver Board: Amazon.com: Industrial & Scientific I like it because it has the inputs on one end and the motor and power on the other end, so you can keep your wiring separated. You can find similar ones based on the TB6560 chip, but be careful. Some of them are junk. The SainSmart ones for instance work, but the switch settings legend on the board is snafu. Took me a while to figure out how to get it to work properly... I've found them on Ebay also for as low as $8. PS - they get pretty hot at 3A, even with the heatsink. I would recommend a fan.