Can we use two Z endstops? / Macro Qualifiers

  • If I do a homing with a cold bed and hotend my inductive Z-Probe is in a slightly different position, doesn't detect the bed and crashes. I've been able to use a microswitch wired in parallel to the inductive probe positioned slightly lower and it works fine. I've seen in the example for M851 that one is allowed to use E1:2 such that an event on either E1 or E2 endstop will trigger the desired results.

    Is there syntax that will allow one to use E0 or Z to trigger a homed event? Below is my current setup:

    M558 P4 X0 Y0 Z1 H4 F200 T5000 I1	

    If the answer is no how could one only run a macro like

    home all

    only if both temps are at expected values or above?

  • administrators

    I've heard before that the cheaper types of inductive sensor are temperature-sensitive. There isn't any provision for using multiple endstop or Z probe inputs in the firmware. I suggest you either stick with your present setup, or get a better Z probe, or home using the microswitch but use a G30 command in your slicer start gcode to set a more accurate Z=0 height after the hot end and bed are up to temperature.

  • Could you not use your sensor and microswitch wired in series, configured as normally closed you'd need either the right sensor (or a relay or transistor to change the signal from No to NC). This way if either triggers the signal goes from high to low/zero and registers triggered?

  • @dc42,
    Good to know about the temperature sensitivity. I'll stick with what I have for now, thanks.

    Thanks for the suggestion but 2 sensors in a series configuration isn't what I'm looking for. My current hardwired solution is functioning as intended.

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