Hi, tk421
Don't know what type of machine you planing on building.
But most steppers need up to 10 times the voltage rating to run them properly.
If this is the specs. on your board.
# 4 Axis Unipolar Chopper control. NO "Ballast" resistors required!
# Individual OR simultaneous control of 2/4 Phase Stepper Motors.
# Accepts 5, 6, or 8 wire stepper motors only.
# 42VDC maximum input voltage, 12VDC minimum input voltage. 24VDC Minimum Recommended Voltage.
# 3.0 Amps Maximum per Phase, 500ma (.5A) minimum. Each axis adjustable throughout this range.
# 1/2,1/4, 1/8, and 1/16 Microstepping .
You need to have a power supply around 40-45 volts and steppers with a rating of around 3 volts 3 amps, check the rating of your small steppers.
For the steppers you described, you really need to use a driver / control box, like the Gecko drives, there rated at 90 volts and up to 7 amp's, selectable amp setting.
The way steppers work, Voltage drives the Amprage the control boxes limit the current, the faster the stepper rotates the amp's drop off
for a give voltage the box allows an increases in the voltage to keep the amps at the max amp rating.
This allows the stepper to maintain it's Torque at higher speeds, which is limited by the max voltage of your power supply.
At rest the voltage on steppers is very low, the control box limits the amps to a safe amps value as not to burn up your steppers.
Let us now if you have more questions.
Hope this makes sense, Chip