Dual z axis, G32, z axis off level

  • Hello,

    After G32 command the nozzle at the beginning of the x axis is +0.05 off the bed and at the end of the x axis is -0.10

    Mesh bed leveling sees the gantry sag before G32. After the G32 command it does not see the sag but it's there.

    I'm using Ender 3
    left leadscrew is 30mm to the left of the nozzle x0
    right leadscrew is 30mm to the right of the nozzle x230 (axis limit)

    Here is my related config.g

    ;dual z axis limits                             
    M671 X-30:260 Y0:0 S2                        ; leadscrews at left (connected to Z) and right (connected to E1) of X axis
    ;M208 X10:190 Y30:230                            ; X carriage moves from -5 to 205, Y bed goes from 0 to 200
    ; Axis Limits
    M208 X0 Y0 Z0 S1                               ; set axis minima
    M208 X230 Y230 Z230 S0                         ; set axis maxima
    ; Z-Probe PINDA
    M558 P5 C"probe" H3 F300 T6000 A20 S0.005     ; PINDA
    ;M308 S2 P"e1temp" A"PINDA" Y"thermistor" T100000 B3950 ; PINDA TEMP OK
    G31 P1000 X-41 Y23 Z0.9
    ;G31 P100 X-41 Y23 Z0.585
    M557 Y45:195 X30:185 P9                        ; define mesh grid OK
    ; Tools
    M563 P0 D0 H1 F0                               ; define tool 0
    ;G10 P0 X0 Y13 Z-0.80                                ; set tool 0 axis offsets
    G10 P0 X0 Y13 Z0                                ; set tool 0 axis offsets
    G10 P0 R0 S0                                   ; set initial tool 0 active and standby temperatures to 0C 

    and my bed.g

    G30 P0 X18 Y115 Z-99999 ; probe near a leadscrew, half way along Y axis
    G30 P1 X210 Y115 Z-99999 S2 ; probe near a leadscrew and calibrate 2 motors
    G28 Z

    Where are my mistakes?

  • Moderator


    As it looks like the correction is going the wrong direction, make sure the left leadscrew motor is plugged into Z and right to E1, and your M584 should be M584 Z2:4 (rather than Z4:2). The order it is defined matters!

    Looks like your leadscrews are in the middle of the bed in Y, so change M671 to:

    M671 X-30:260 Y115:115 S2

    It may make a small difference.

    Your probing speed F300 (5mm/s) in M558 is pretty fast, and can lead to inaccuracy; try F120 (2mm/s). Though you do have A20 S0.005 set, so it should probe a number of times anyway.


  • Thank you! setting Y115 worked. I still have issues with inconsistent Z leveling, different order of commands seems to give diffierent results.

  • Moderator

    What order are you using? Bare in mind that any change in the tilt of the gantry will change the distance to the bed as well.

Log in to reply