Specifications  Part No.  10010  Type  Uni-polar, L/3R  Step Mode Half stepping Dimensions  11" x 7" x 4"  Weight  5 lbs  Power Supply  In: 120VAC, 60 Hz.  Out: 11VDC, 6A (66 Watts)  Fan  3" AC  Input connector  25 pin female (male-male cable included)  Output  Three 8 pin DIN sockets, 3.6VDC, 2A each  Switch  Red lighted push button  Case  Alum. base, 4 rubber feet, Black steel vented hood

Although this looks like the Pro controller, only the box is the same.  The internals are much simpler for this unipolar controller and the 4th axis is not available.

The three-axis unipolar motion control driver can provide up to 6 amps of power at 11 volts.  Output to each stepper motor is fixed at about 3 VDC and 2A.  This is a "phase" type controller where power to each of the 4 stepper motor windings is sent in a sequence controlled by software, not hardware.  Third-party software that runs only Step/Direction type controllers will not run this controller.  The MyT'Mill software can run either kind.

With this controller, the MyT'Mill software is capable of shutting down power to any motor that is not moving to make that power available to the other motors.  This controller can drive the MyT'Mill stepper motors to a top speed of about 6 in/min (120 rpm).  While not quite as fast or powerful as the bipolar drivers, this unipolar driver produces motion that is a little smoother and quieter at the slower machining speeds.  It was our only controller offered for several years and is a proven, quality design.

The box measures 11" x 7" x  4" has four rubber feet, a lighted on/off switch and weighs 5 pounds.  It plugs into your PC's printer port with a 25 pin DB25 M/M cable. Round 8-pin DIN type connectors terminating the stepper motor cables plug into X, Y, and Z labeled sockets on the box's front panel.

Unipolar controllers run hotter and are less efficient than bipolar controllers because they use resistors which drop the supply voltage down to rated motor voltage.  Torque drops off quicker with a unipolar driver because as electrical impedance increases with motor speed, the voltage stays the same causing less current to flow through the windings.  And torque is directly proportional to current.  Bipolar controllers are able to increase the voltage to maintain higher currents.  This controller can only run motors that are about 3 VDC and 2A, unlike the Pro controller which can drive any motor up to 24 VDC or currents up to 3.5 A.  This controller can only run 3-axes and cannot be upgraded to 4, like the Pro controller.