Independent z axis with z-Endstop and z-Probe in RRF3



  • Hey guys,

    I recently switched to RRF3 for my new CorEssentials machine which uses 4 indipendent z-axis. I use a Duet Maestro + 2 Additional steppers. A similar setup to the Voron 2.

    I've set up everything mostly correctly - at least I think so. I am able to home x,y,z and probing the bed near the z-axis belts works as well. But I have a problem with configuring the z-endstop position. It's set to z=0 at the moment via M208.

    My idea / homing procedure is something like this:
    G28

    • Home x,y
    • go to z-endstop and home z
    • Clean nozzle on wire brush
    • home z again
      G32
    • go to 4 points near the z-axis belts and "align" them afterwards.

    The Problem:
    My z-Endstop triggers at z=1mm (but firmware sets it to z=0mm) and the G32 can not correct the beds "tilt" because the bed is "out of reach / probe did not trigger while probing".

    What is the correct way to "implement" the z-Endstop position with z_endstop_pos = 1.0mm and without limiting the movement of the printer (e.g. software endstops?
    I know I just can add
    G92 Z1
    in the homez.g, but I do not think that is an elegant solution.

    Thank you for your suggestions.
    Max



  • Hi,

    The G1 move with the H1 parameter sets the Z position to Zmin, which in your case is 0. So after the second such move in your homing code add G92 Z1 or whatever the actual Z position is.

    Frederick



  • @MacNite said in Independent z axis with z-Endstop and z-Probe in RRF3:

    I know I just can add
    G92 Z1
    in the homez.g, but I do not think that is an elegant solution.

    What is not elegant about it?

    Is your Z probe mounted on the print head? Why not use the probe to home Z0?



  • @fcwilt said in Independent z axis with z-Endstop and z-Probe in RRF3:

    Hi,

    The G1 move with the H1 parameter sets the Z position to Zmin, which in your case is 0. So after the second such move in your homing code add G92 Z1 or whatever the actual Z position is.

    Frederick

    Yes, that is the not elegant option I mentioned above

    @Phaedrux said in Independent z axis with z-Endstop and z-Probe in RRF3:

    @MacNite said in Independent z axis with z-Endstop and z-Probe in RRF3:

    I know I just can add
    G92 Z1
    in the homez.g, but I do not think that is an elegant solution.

    What is not elegant about it?

    Is your Z probe mounted on the print head? Why not use the probe to home Z0?

    The z-Probe is mounted to the carriage. But I have "quick swap" tool heads so If I change a standard V6 for a Volcano I don't have to re-calibrate the nozzle-height. This is handeld by the z-Endstop.

    It don't think it is elegant, because I'd have to open the homez.g file in addition to the config.g. I'd rather have everything mandatory configured in the config.g - just to get it more "streamlined".

    Greets
    Max



  • Hi,

    You might not consider it "elegant" but it Is the simple and not uncommon solution.

    You can of course adjust your endstop switches so they trigger at just the right place.

    But tweaking positions in code is perfectly fine and is used, for example, in the delta calibration process.

    Frederick



  • Elegance is a matter of opinion, and I won't try to convince you in any direction.

    At the same time, I regard the things that are separated into home?.g and bed.g and so forth, I regard those as elegant because they provide "logical categorization" for the commands that are involved in homing, or whatever.

    To say it another way: homez.g is doing exactly what it is designed to do, by being separate from the rest of the configuration.

    So... I said I wouldn't try to convince you... and hopefully I haven't... just stating how I see it.


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