Short to ground on driver 3



  • Good morning all

    My printer has been working great for at least a month. About 9 hours into a print it threw this error a few times in the logs. Any ideas on what could have happened? What should I look at?



  • which duet?
    have you measured the resistance of each wire of that stepper?



  • A maestro. No I haven't done anything like that


  • administrators

    If you only get that report occasionally, it probably means that you are using stealthchop at too high a speed on that driver. Are you using firmware version 2.02 ?



  • Yes I'm on 2.02. This is the first time I've seen it. Which driver is 3?


  • administrators

    Driver 3 is the one labeled E0. What M569 P3 command do you have in config.g, if any? If you send M569 P3 with no additional parameters, what does it report?



  • In my config.g:

    M569 P3 S1 ; Drive 3 goes forwards

    Command run:

    2:31:16 PMM569 P3
    Drive 3 runs forwards, active low enable, step timing fast, mode stealthChop, ccr 0x00053, toff 3, tblank 0, hstart/hend/hdec 5/0/0, tpwmthrs 2000 (1.0 mm/sec)


  • administrators

    @falcar, those values look OK to me.

    Are you quite certain that there isn't an intermittent short circuit? Sometimes when crimping a wire, one strand can escape being crimped and cause a short to an adjacent pin. Also check that the back of the Duet can't be shorting against something underneath it.

    How long is that stepper motor cable, and what sort of cable is it? It might be that a cable with a particularly high capacitance between the wires or to ground could trigger the short-circuit detection.

    To check whether the reports are related to stealthChop, you could put the extruder into spreadCycle mode by adding parameter D2 to your M569 P3 command in config.g, and see whether that stops the reports.



  • The wire isn't very long. It's one I purchased off of Amazon. I will check to make sure there are no wires loose or shorting.

    I'll also try the other mode too if I don't find anything.

    If I discover the problem will this error have caused any irreparable damages ?



  • stealthchop2 can be problematic on the extruder as it will skip easily

    add M569 P3 D2 to your config to disable stealthchop for the extruder.



  • Rewiring seems to have solved the issue. For safety sake I think I will also remove stealthchop.

    Thanks guys!

    Any idea a good source to purchase more of them connector ends? I used all of the ones that came with my wifi on my maestro!



  • depends on how low you want to wait. search amazon for KF2510 set


  • administrators

    @falcar said in Short to ground on driver 3:

    Any idea a good source to purchase more of them connector ends? I used all of the ones that came with my wifi on my maestro!

    See https://duet3d.dozuki.com/Wiki/Connector_and_spare_part_numbers for the connector part numbers.


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