I want to control respectively 4 motors already mapped to Z-axis



  • Four motors are used on the z-axis. The bed is 1000mm by 500mm, 10mm thick aluminum, very rigid.

    I'm struggling to automate bed leveling.

    The procedure I want to try is :

    1. Mapping 2 out of 4 motors as if they were one
    2. Automatic 3 point bed leveling
    3. Manually adjust gap where the bed is floating.

    To do this, we need a method of bundling two motors and treating them as one motor.



  • you can easily map them.

    for example

    M569 P0 S0                                     ; physical drive 0 goes backwards
    M569 P1 S0                                     ; physical drive 1 goes backwards
    M569 P2 S1                                     ; physical drive 2 goes forwards
    M569 P3 S1                                     ; physical drive 3 goes backwards
    M569 P4 S1                                     ; physical drive 4 goes backwards
    M569 P5 S1                                     ; physical drive 5 goes backwards
    M569 P6 S1                                     ; physical drive 6 goes backwards
    M584 X0 Y1 Z2:3:4:5 E6                               ; set drive mapping
    

    In the M906 you need only one Z parameter

    M906 X800 Y800 Z800 E1000 I50                  ; set motor currents (mA) and motor idle factor in per cent
    

    After that you can use this wiki entry

    https://duet3d.dozuki.com/Wiki/Bed_levelling_using_multiple_independent_Z_motors



  • @PCR

    Thank you for your reply.

    I'm already doing it the same way you do, and I already know the wiki.

    My question is some sloppy, so I want to change the question,

    what if I want to control respectively the four motors already mapped to Z-axis?

    3 Z-axis bed leveling is so simple, but leveling 4 Z-axis has many limitations with rigid not flat bed.



  • @psyblue

    you could try assigning each of the z mother additional axis. to U, V, W, A and setting the P value so they are visible

    then you can manually control them as well.

    big but, it might be better if you convert one axis to just a support axis as 4 point bed levelling is problematic. see https://drmrehorst.blogspot.com/2017/07/3-point-print-bed-leveling-vs-4-point.html


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