Bed not stopping after Piezo Orion has triggered

  • Hi folks,
    I'm experiencing an intermittent issue with my Duet equipped Hypercube Evo.
    After the last print worked fine, the Duet doesnt seem to recognize the Orion trigger signal and moved the bed into the nozzle. The LED turns blue and the Z-Probe value in DWC turns to 1000 but the bed doesnt stop.
    It can be seen here:

    Here's a pastebin of my config (which worked fine before):

    I already talked to Idris and measured the signal voltage of the Orion which was fine.
    I also went through the usual procedure with loosening the orion mount screws etc.
    What also makes me wonder is that the Z value is the following after the bed is stopping (when it pressed the entire assembly up for about 5-10mm):
    alt text

    Any help is appreciated!


  • administrators

    M558 P8 I1 R1 H5 F480
    G31 X0 Y0 Z-0.05 P100 ; Set Z probe trigger value, offset and trigger height

    If the Orion produces a negative-going trigger, then those values look OK to me.

    Are you sure that you are consistently getting a reading of 1000 when the probe triggers, and the problem isn't a bad connection between the output of the Orion and the Duet? With a probe that produces a negative going signal (i1 in the M558 command), a disconnected output wire looks the same to the Duet as a probe that is not triggered.

    Also try running M558 without parameters form the console, to check that the values you set in config.g haven't been overridden. Similarly, check the G31 values by sending G31 T8.

  • The output of the Orion is active low.

    Paul and I went through all the trouble shooting steps I could think of last night. He measured voltages of 3.233 untriggered and 0v triggered. This is at the Orion end of the cable, however, since the Orion uses an open drain output, a broken cable would result in a floating pin that normally measures ~0.5v. He also tried with three different cables.

    What's really puzzling to me is what's shown in the video, the Orion triggers lighting the blue LED but the bed keeps moving. If there were an issue with the sensitivity of the Orion or its triggering then I would expect to see the bed hit the nozzle, keep moving, and then have the Orion trigger. It appears that the Duets response to the trigger signal is delayed for some reason.


  • Thanks for the answer!
    Yes, the Orion is indeed produing a active-low trigger, as clarified with Idris.
    I'm getting a value of 1000 whenever the probe / nozzle is tapped on. The connection between the Orion and the board is fine, i double checked that with 3 other spare cables.
    Here's the output of M558, looks good to me:
    alt text
    and of G31 T8:
    alt text


  • My config that works, for orion precision piezo:

    M558 P5 I1 R0.4 F300 X0 Y0 Z0
    G31 X0 Y0 Z-0.0 P10

  • Any ideas on this issue?

  • administrators

    Bad connection in the output pin of the cable?

  • @dc42
    I tried with 3 different cables with no luck.
    In the meantime, Idris sent me a replacement Orion, I'm going to check this soon and report back

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