Your sun tracker or heliostat will require two stepper motors to make it move, one for the altitude motion and the other for the azimuth.
These bipolar stepper motors were chosen because they have good torque, are compact, and work great with the Sun Harvester Driver Board.
They are perfect for a small to medium sized machine provided you use the appropriate gear reduction relative to the machine's size.
You will receive two bipolar stepper motors with this purchase.
These bipolar (4 wire) stepper motors can be wired to the Sun Harvester Driver Board as follows:
Red wire --> A+
Yellow wire --> A-
Green wire --> B+
Grey wire --> B-
*200 steps per revolution, 1.8 degrees per step
*5mm shaft diameter
*12V rated voltage
*34 Ohm winding resistance
*28 oz*in, 20 N*cm, 2 Kg*cm holding torque per phase
More in-depth information can be found in the Datasheet