Stepper cable issues?



  • Hi guys

    I feel this is a stupid question at it's basic level however I have been left perplexed by a simple cable. So I bought a simple stepper motor cable to add dual z to a Cartesian style printer but when I plugged the cable in to the zb slot I got an error saying short to ground on driver 2 (z driver). I checked the wiring which was fine the stepper was known to be good. I jumped to the conclusion that there was an issue with that driver one way or another. I went down the rout of assigning E0 as U and configured it for independent endstops. However once again I got an error on driver 3 using this cable. I used the extruder cable and all worked fine. I checked with a multi meter and there are no shorts between phases.

    Question: what the hell can a cable do to cause this?

    Anyone encountered this?

    Thanks,



  • the order of the cables is important.
    Make sure it is correct.



  • Yea I checked that and they both go red, blue, green and black. This leads me to believe I could only plug it in the wrong way and reverse motor direction. I would put a picture for what it's worth but it seems forums of 2018 still need links.

    It's got me scratching my head to sure.



  • Dont trust the colour coding, it is not a standard, measure your pairs with a multimeter. You can upload photos with the "upload image button".



  • @whosrdaddy said in Stepper cable issues?:

    You can upload photos with the "upload image button".

    Or drag-and-drop them into the editor.



  • @wilriker Nice, didn't know that 🙂



  • @whosrdaddy

    From the category: what I always wanted to know: is it important whether it's red-blue-green-black or blue-red-green-black (if pairing red+blue and green+black). I wonder because the magnet fields should have an influence on each other when current flows different in the two cases.
    And if they are different somehow, how to find out which one is better?



  • @joergs5 said in Stepper cable issues?:

    @whosrdaddy

    From the category: what I always wanted to know: is it important whether it's red-blue-green-black or blue-red-green-black (if pairing red+blue and green+black). I wonder because the magnet fields should have an influence on each other when current flows different in the two cases.
    And if they are different somehow, how to find out which one is better?

    No "optimal" ordering of the physical, because, if you swap the ordering of cables... then you must also re-configure the driver to get the rotation direction correct... and that reverses the current. Meaning, everything is the same as it was before you swapped cables, in terms of the polarity of the fixed magnets vs. the polarity of the coils. And/or the coils in relation to each other, etc.



  • @danal I meant whether the magnet fields have different influence, when one thinks of the 8 coils side by side. But your aspect that direction is reversed matters also of course. In fact you have 4 possibilities to order the paired colors.

    Edit: ok, I think I understand it now.



  • Easy way to find the coil pairs in a motor, without an ohmeter:

    Turn the motor with your fingers. Get a feel for how it turns. Put a pulley on it if it is too stiff to turn the bare shaft.

    Pinch wires together (short them) in pairs. When you have a pair pinched together, the motor will get "stiffer" (MUCH stiffer). When a non-pair is pinched, the motor will feel the same.

    Work your way through all possible combinations of two wires, and the coil pairs will be very obvious.



  • @danal I knew that trick, but managed somehow to confuse black with blue anyhow... The controller still lives (phew).



  • Guys....My bad.

    So with everyone saying it's easy to upload pics I thought I would give it ago but then decided to go one better and make a video. Anyways while tidying up the work bench I removed the cover from the duet I noticed the colour is different from the plug on the stepper motor , i had thought I checked this however tiredness must of dropped my IQ 30 points.

    In a nut shell the wires were wrong, I had some how got caught up in making sure the pins each end were the same without knowing for fact that they need to be wired that way.

    Stupid mistake, sorry to waste everones time but thanks all the same. Goes to show checking the obvious can be the way forward.😅



  • @scottpickstock said in Stepper cable issues?:

    Guys....My bad.

    So with everyone saying it's easy to upload pics I thought I would give it ago but then decided to go one better and make a video. Anyways while tidying up the work bench I removed the cover from the duet I noticed the colour is different from the plug on the stepper motor , i had thought I checked this however tiredness must of dropped my IQ 30 points.

    In a nut shell the wires were wrong, I had some how got caught up in making sure the pins each end were the same without knowing for fact that they need to be wired that way.

    Stupid mistake, sorry to waste everones time but thanks all the same. Goes to show checking the obvious can be the way forward.😅

    No problem, just glad you found it!


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