Optical endstop problem and multiple Z motors



  • Hi, I'm retrofiting some big core xy printers with duet 1.04.
    They have three big Z motors and an optical endstop on each to level the gantry because the bed of 800x800 is fixed.

    Q1: the optical endstop connected to Z probe runs on 24v, I read 24v when triggered and around 1.5v when not triggered. So the duet always sees a triggered state. Do I need to connect a restor to ground or on the signal pin?

    Q2: is it possible to assign each endstop to the corresponding motor so we can level the gantry or is a z probe on the head the only way?

    Thanks in advance


  • administrators

    @furbyhaxx said in Optical endstop problem and multiple Z motors:

    Q1: the optical endstop connected to Z probe runs on 24v, I read 24v when triggered and around 1.5v when not triggered. So the duet always sees a triggered state. Do I need to connect a restor to ground or on the signal pin?

    Yes, try a resistor between the signal pin and ground. 4.7K or 10K should be a suitable value.

    Q2: is it possible to assign each endstop to the corresponding motor so we can level the gantry or is a z probe on the head the only way?

    Yes it is possible, see https://duet3d.dozuki.com/Guide/Independent+Z+motors+and+endstop+switches/18?lang=en. It's easier in RepRapFirmware 3 but that is still in beta.



  • thanks, when I mesaure across GND and Z PROBE IN I get constant 3.2v, when probe is not triggered and around 17v with a 10k resistor. without the endstop connected I also read 3.2 between GND and Z PROBE IN, is there something defective?


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