4th axis wiring

Here is the guy I got my info from.

So you can’t go by colors you have to know what wire is the A+, A-, B+, and B- of the stepper motor you are using is and then wire those into the correct port on the motor connector in the controller.

I agree. I always find and print the data sheets from the controller and stepper motors I am using (Buildbotics and ? in your case), then confirm the colour connections from those.

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So where do I find the wiring codes on this one?

Hey DaBooBear,

you will always find them on the datasheet. If you get not datasheet with it, I would stay away from the item. However if the stepper has only four wires, it is possible to find out the wiring (see below).

A very good document for understanding how to wire stepper motors is

If your stepper has four wires, it says:

The trick is figuring out which wires make up the coil pairs. Here’s three ways to figure this out:

  1. Find the documentation for the motor. Assuming you don’t already have it, read the model number off of the motor and then search for it on the Internet. With a little effort, it is usually possible to get a datasheet for the motor. The datasheet will usually specify the wires by A+, A-, B+, and B-, or at least show which wires by color attach to which coils.
  2. If you can’t find the datasheet, but have an ohmmeter, measure the resistance between any two of the motor wires. If you measure a near short, then that pair makes up one coil, and the other two wires make up the other coil. If it is an open, then measure between the first wire and another wire and then to the fourth wire until you find a near short. Notice that I say near short because the coil is a long thin wire and has some resistance. Once the pairs are identified, then arbitrarily assign one pair as “A” and the other as “B” and arbitrarily assign one wire as “+” and the other as “-” within each pair. Then connect the wires as shown. There is a 50% chance that the motor will turn backwards when connecting this way. If it does turn the wrong way simply reverse one (not both) of the pairs and the motor will turn the other direction.
  3. If you don’t have an ohmmeter, most people can identify the pairs by feel. Stepper motor shafts turn fairly easily when the motor coils are open, but are more difficult to turn when a coil is shorted. First, leave all four motor coils open and turn the motor shaft to get a feel for how hard it is to turn. Then twist any two wires together. If the motor is significantly harder to turn, then you have shorted one of the coils and identified a pair. If not, disconnect the two wires from each other and connect a third wire to the first wire. If the motor doesn’t get harder to turn, disconnect the third wire from the first wire and connect the fourth wire. One of the combinations should be harder to turn and that is one coil and the two wires make up the other coil. Once the pairs are identified, then arbitrarily assign one pair as “A” and the other as “B” and arbitrarily assign one wire as “+” and the other as “-” within each pair. Then connect the wires as shown. There is a 50% chance that the motor will turn backwards when connecting this way. If it does turn the wrong way simply reverse one (not both) of the pairs and the motor will turn the other direction.

– Source: Wiring Stepper Motors - buildbotics

Further Information

Good video: (Disassembles stepper motor and explains its use very well):
GreatScott!: Stepper Motors and how to use them

Very good video (not to be missed):
Stepper Motors Advantages and Disadvantages

Very good page:
Stepper motor - Wikipedia

Further Video watching:

Precision motion control: ODrive Servo? Trinamic Stepper? Chinese Hybrid?

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If it’s not listed in the posting or in the Q/A of the item you could ask them or do the above. If that is the same one I bought and posted about then it is listed in the Q/A section. I think I also posted it in my write up.

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From the Amazon link I found for this 4th axis, the wiring diagram shows red and green are one coil pair, and yellow and blue are the second coil pair. The Buildbotics website gives the connector positions for the motor A+/-, and B+/- (left side of molex is the B coil pair, right side is the A pair). As long as you don’t cross motor coil pairs you should avoid shorting your controller’s driver. Once you have one motor pair connected to one connector pair, then the second, you can test for direction. If direction is incorrect, reverse the wires, but only do this within one wire coil pair (not both and not between coil pairs).

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Thank you all. TMTronto, that last comment may help but I think I have it set correctly. If you look At the picture I connected red/red, green/green, blue/blue and yellow/black. According to Nema 23 the wires are
Blue- B-
Red- B+
Green- A-
Black- A+

I’m spicing spare wire from Onefinity. The picture it appears the wires should be
Blue to blue
Red to yellow
Green to green
Black to red

After testing with an Ohm Meter, this is what I found. Will try connection tonight or tomorrow. The Red/Green on the left and the Blue/Yellow on the right. If correct the rotation should move forward toward front? Correct? If opposite I should switch what? The two +s or a + and a -?

From what I have learned, only switch the +/- of one coil pair, not between coil pairs.

Thanks TM. I’ll try it out and let y’all know. Probably this thread would help others if they aren’t sure.

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OK I’ve tried everything. Inserted is a picture of how it is supposed to be wired. After wiring it still didn’t do anything. I am completely stumped. I set my Configuration exactly as Roger said in his directions. Any ideas as what to try next? Oh, BTW, the stepper motor does work. I tested it. I’m trying to move it with the joy stick. Could that be it? Lost.

Do you have a multimeter by chance?

Yes. An old one but it works.

Perhaps see what voltage the driver is sending to the motor across the A and B pairs, measured at the M1 female moles at the controller.

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Thanks I’ll try later today but a few questions.

  1. Do I check with the 1F turned on?
  2. Do I check at each (A+/-, B+/-)? And what setting do I use? I have 10 ohms and 1000 ohms.
  3. What number should I be looking for?

Can you answer my questions below?

I was thinking of troubleshooting slowly, starting from the source. So I thought we could check to see what the drivers are sending out to the stepper motors.

With the 1F turned on, and only the X and Z axis motor cables plugged in, use the joystick to confirm that these motors work as expected. I would also use the MDI to give an X and Z movement as well. (I am assuming all your motors are still attached to your 1F).
Using your multimeter, I would be interested in checking what voltage is being sent out to the Y stepper motors. I believe the controller uses a 24DC power supply, so set your multimeter to a voltage range that covers that. You want to test the voltage within each coil, not between. Check with probes connected to A+/A-, and B+/B- (not between As and Bs). This should also be done when you are commanding the Y motor(s) to move . Try first with the joystick, but also with MDI commands in case you have any axes locked on the gamepad (see NOTE) below. I believe you should be getting a voltage reading (don’t worry about +/-) for the A and B sides of the connector. I would also do this with the original motor settings, not any rotary configuration, as that can be part of future testing. Also, to keep it simple I would have my 4th axis motor cable with its own Molex connector going straight to the motor output of the controller (making sure you have the wiring done correctly). I have not reviewed your wiring, so will assume it has been done correctly. Once we know the Y drivers are VDC, we can continue the troubleshooting. Do not plug/unplug any motor wires while the controller/drivers are powered.

NOTE: I do not use this controller, motors, and joystick/game pad. I believe I read in the forum that the joystick can lock axes movement so that only one axis at a time moves allowing, for example, the controlled manual surfacing of stock. Is it possible that in your earlier testing you accidently had the Y axis locked out?