Using Z-max end stop for resurrect prologue

  • Hi
    I'm looking at resurrect after power down at my core xy hevo. I have a z-max endstop and a IR z-probe.
    Until now I use the z-probe as z-min endstop.
    However for the resurrect-prologue I want to lower the bed until z-max endstop. How would I do that?

    in config.g I can set
    M574 Z1 S2 to use the z-probe as z-min endstop

    I could then lower the z bed until it hiys the z-max end stop en note the z position: let's cal it Zmax

    When I then, after a power down, in the resurrect-prologue set
    M574 Z2 S1 use max-z endstop
    G1 S0 Z-300 go to z-max endstop
    G92 ZZmax
    M574 Z1 S2 revert to using z probe
    And then do the rest of the resurrect, would that work?? would that get me at the correct z-height in order to resume printing after power down?

  • administrators

    If you normally use the Z probe for Z homing, and you use G30 commands in homez.g and homeall.g to do Z homing (which is the correct way when using a Z probe to home Z), then you can use M574 Z2 S1 in config.g and never change it.

    This line in resurrect-prologue.g:

    G1 S0 Z-300 go to z-max endstop

    should be:

    G1 S1 Z300 go to z-max endstop

    You don't need the G92 Zmax command, instead set the M208 S0 Z parameter to the Z value at which the endstop switch triggers.

  • Thanks. That helped a lot…
    And also thanks for all support. It show that you get what you pay for:)

  • One more question regarding M208 S0 to set the zmax endstop height.. When I run auto bed level/mesh grid after e.g. changed the bed level screws..the height will be different. Is it G32 I use to move to Zmax and calculate the correct Zmax height. And how does that work with the bed.g file ?bed.g replaces G32 or is it executed after G32?

  • administrators

    Here's a way to set the ZMax height (needs 1.20 or later firmware)

    1. Home the printer as normal, with Z homing done by G30.

    2. Send G1 S3 Z300 Fxxx to run Z up to the max endstop (if you prefer you can jog Z up most of the way first if that is faster). The S3 makes it stop when the endstop is triggered, but instead of resetting the Z position to the M208 value, it does the opposite.

    3. Either send M500 to save the new M208 value in config-override.g, or send M208 to get a readout and edit the new value into config.g.

  • brilliant, thanks again!

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