[jeffmorris]

How do I connect the Probotix PBX-RF breakout board to MondoStep 7.8 Stepper Motor Drivers? Which fuses should I buy for the drivers? Are the colors of the wires on the stepper motors same on all stepper motors?

[jeffmorris]

I got the package from Probotix today. The colors of the wires on the stepping motors are red, green, white, and black. How are the wires connected to the MondoStep 7.8 Bi-Polar Stepper Motor Drivers? The motors are made by Eastern Air Devices and the labels say “5A/10A 1.8 DEG LA3ABJK-P500”. I tried to find info on the motors on the Internet but I couldn’t any info. I had to steal the 10-pin IDC adapter cables from my other machine. Please reply ASAP.

[doorknob]

Do you have a multimeter available?

Since the motors have four wires, it should be easy to do an electrical resistance test (or continuity test) to find two sets of two wires, with both wires in each set connected together.

To say that more clearly, strip a small bit of the insulation from the ends of each of the wires, make sure that the ends of the wires are not touching each other (and not touching any metal object), measure the resistance (with the multimeter set on a low- or middle range) between the red wire and each of the other three wires - one of the three wires should show a low resistance (close to zero ohms), while the other two wires should show a high resistance. The red wire and the other wire showing the low resistance go to one winding. The other two wires go to the other winding (you can test the resistance between the other two wires, which should be close to zero).

Your driver should have terminals available for connection to two separate windings (they may be marked as winding A and winding B, for example). It does not matter which pair of wires you connect as winding A and which you connect as winding B. Within a given winding, it does not matter which wire goes to which terminal (for example, one terminal may be marked as A and the other marked as A' or similar).

[jeffmorris]

I think that I found a manual for stepper motors that have the same colors of wires that my stepper motors have.

http://www.automationdirect.com/stat...manual/ch4.pdf

[doorknob]

I would not assume that all manufacturers use identical color coding for stepper motor wires.

Your best bet will be to do the resistance check that I described above.

[jeffmorris]

I used a test light to find out which wires are connected to which phase. The black and white wires are connected to one phase and the green and red wires are connected to other phase. I got the machine running today but the Z-axis is reversed and I need to tune the motors. Which wires should I switch to switch the direction of Z-axis? If the TPI of the ACME screw rod is 6 and the steps per revolutions is 1600, how do I set the correct speed in Mach3 software so that the stepper motor moves the X-axis 4 inches instead of about 5 inches? My original plans were to keep the relays and switches that control the vacuum cleaner, router motor, and vacuum hold-down but I think that they were controlled by the old CNC controller. I will have to remove the relays and install switch-controlled outlets for vacuum cleaner and router motor. How do I find out if the E-Stop switch that came with the machine is normally closed or open? I need to wire the E-Stop switch and limit switches to the Probotix PBX-RF board.

[doorknob]

You should be able to change the direction of the Z axis either by changing the direction definition in the software or else by reversing one pair of motor leads (leaving the other pair alone) from the Z-axis motor. Make sure that your stepper driver power is off when disconnecting and reconnecting the stepper wires.

You should be able to use your test light to determine whether your E-stop switch is set up for NC or NO (or maybe it has terminals for both). You should probably disconnect the switch from any other wiring before doing that test.

Somewhere in the Mach3 setup or tuning it should let you tell the software how far you think the axis has moved, compared with how far it actually moved, so that Mach3 can figure out the proper steps-per-unit setting. I have not done it in a while, and so I do not remember where to find that definition.