CNC MightyBx III Micro Step, Unipolar, 3 Amp, Step Motor Drive Controller


Computer Controlled Wood Routers, 3 Axis Mills, Plasma Torches, Lasers, XYZ Tables.
Drives Three(3) Size 23, Stepper Motors.
Three(3) Ampere/Phase Maximum Unipolar Current.
Two(2) Dry Contact 10 Ampere Control Relays.
Desktop Parallel Port Interface.

The Mighty Box III was designed to drive NEMA 23 stepper motors.  It uses the parallel printer port to control four Unipolar stepper motors, no modification or additions must be made to the computer.

Stepper motors can be driven without taking the cover off the computer.

Hookup to the computer is as simple as plugging a cable into the Parallel Printer Port on your computer.

The interface connector is a DB25 female, with the standard pin out. A straight Male to Male cable is provided to connect to the PC parallel printer port.

The XYZ Electronic Motor Controller was developed to be plug and play compatible with the CNC machine control programs.

The two(2) internal dry contact relays can be used to switch AC or DC voltage. Relay A is controlled by Pin 6 and Relay B is controlled by Pin 7. When the relay pin is high the relay will be engaged.

There are two connector panel styles. The panel can have either power recepticals for the main input AC or a terminal block with the Normally Open Contacts presented.

The two relays can be used to control items such as a Spindle, Plasma Torch, Laser and Coolant on/off. The maximum contact switching current is 10 Ampere.

The controller can be used to drive three stepper motors, this configuration is good for XYZ mechanical table designs that move the material, such as a metal working Mill and some engraving machines.

Motor timing signals are created by the SLA7062 integrated circuit.

Individual motor currents are adjustable by internal trim pots. There are test point pad next to each trimpot. By measuring the voltage at the test point in reference to ground, the motor phase current can be determined. The sense resister is 0.5 ohms, a reading of 1.0 volt at the test point corresponds to 2.0 Amperes, reading 1.5 volt at the testpoint corresponds to motor phase currents of 3.0 Ampere. Turning the trimpots clockwise decreases the motor current, counter clockwise increases motor current. Each revolution changes the current by 0.4 Amperes.

The drive circuit is for Unipolar wired motors, that's motors with five or six wires. The schematic of the the motors would be two center taped coils.

The motors are driven in micro step mode. Internal jumpers can be changed to make the unit drive the motors in 400, 800, 1600 or 3200, by default the jumpers are set to 1600 steps per revolution.

Uses a standard PC Parallel Port interface to attach to the Desktop computer.  Parallel port signal wires are electronically buffered from the motor drivers chips.  Motor step signals are normally low.

Axis X motor Step is on Pin 2, Direction is on Pin 3, Limit Switch on Pin 11.

Axis Y motor Step is on Pin 4, Direction is on Pin 5, Limit Switch on Pin 12.

Relay A is on Pin 4, Relay B is on Pin 5.

Axis Z motor Step is on Pin 8, Direction is on Pin 9, Limit Switch on Pin 13.

ENABLE on Pin 14 engages the motors when High.

*INIT on Pin 16 disables the controller when Low.

HIPWR on Pin 17 enables high current to motors when High, when low the current is about 1/3 of the high current.

There is a Home Limit Switch circuit for each stepper motor. When performing Home Ref operation, the stepper motors step until engaging their individual limit switches.

There are separate connectors for X, Y and Z stepper motors. The individual motor connectors are female DB9, besides the motor phase circuits, there are limit switch and +5 Volt output circuits.

Pins 1 and 6 are the center tap leads for the motors. Pins 2 and 3 are for Phase A and B of the motor. Pins 4 and 5 are for the Phase C and D of the motor windings. Pin 7 has +5 Volts on it powering active home limit switches. Pin 8 is home limit switch sense and Pin 9 is ground the return side of the switch.

There are two internal fans, mounted on each side of the box, one forcing air into the box and the other out of the box. This provides forced air cooling of the power dissipating components. The fans have grills and foam filters, to keep metal shavings out of the box

The internal power supply provides 24 Volts at maximum current draw of 6.5 Ampere. Input voltage can be either 120 or 240 VAC, it is internally fused.

The controller is housed in a steel utility box painted grey. The steel box dimensions are: Height 4" x Width 10" x Length 10". 

The motor controller has a thirty day warranty. Shipping Weight is about 14 lbs.

MightyBx III Price List
Detailed InformationPart# EMC-XYZ-MUBX-K3  XYZ, Unipolar, 1600 Step/Rev, 3 Amp., Three(3) Motor, Three(3) Axis, Step Motor Controller. Two(2) Control the Power to Two Main Power Recepticals on Connector Panel. Internal 24 Volt 6.5 Amp. Power supply, 150 Watt 120/240 switchable. Parallel Port step and direction Interface. In metal utility box 10 x 10 x 4 inches. Three(3) NEMA23, 300 oz/in, 0.25" Diameter Double Shafts, Double Stacked Motors with Home Limit Switches and the Cables included.   Weight: 25 lbs........$1,295.00
XYZ, USB, Unipolar, 1600 Step/Rev, 3 Amp., Three(3) Motor, Three(3) Axis,  Step MotorPart# USB-XYZ-MUBX-K3  XYZ, USB, Unipolar, 1600 Step/Rev, 3 Amp., Three(3) Motor, Three(3) Axis, Micro Step Motor Controller. Two(2) Relay Controlled Main Power Recepticals. Internal power supply, 24 Volt, 6.5 Amp., 150 Watt, 120/240 switchable. USB interface with SuperCamXp. Three(3) 300 oz/in NEMA 23, Double 1/4 inch shafts, Stepper Motors and three(3) six(6) foot motor cables included. USB cable included with controller. In metal utility box 10 x 10 x 4 inches.   Weight: 28 lbs........$1,295.00

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Copyright 2016 Dennis Bohlke
Revised 03/12/16