Bed levelling using multiple independent Z motors



  • Hello

    why will my machine after probing bed make bed not plane level just more curved.
    i am using MINI IR probe from E3D with ZIFLEX print surface.
    Here is my bed code

    G28 ; Home
    G30 P0 X20 Y104 Z-99999 ; Probe near Front Right leadscrew
    G30 P1 X20 Y384 Z-99999 ; PROBE POINT 2 Rear Left
    G30 P2 X210 Y384 Z-99999 ; Probe near Rear Middle leadscrew
    G30 P3 X400 Y384 Z-99999 ; PROBE POINT 4 Rear Right
    G30 P4 X210 Y240 Z-99999 ; PROBE POINT 5 Center
    G30 P5 X400 Y104 Z-99999 ; PROBE POINT 6 Front Middle
    G30 P6 X210 Y104 Z-99999 S3 ; Probe near a leadscrew and calibrate the 3 motors to achieve self
    G28 ; Home
    

    and here part of config code

    ; Drives
    ;X and Y motors
    M569 P5 S0                              ; Drive 5 direction | Y Stepper
    M569 P6 S0                              ; Drive 6 direction | Y Stepper
    ;Z motors
    M569 P7 S0                              ; Drive 7 direction | Front Right Z
    M569 P8 S0                              ; Drive 8 direction | Back Z
    M569 P9 S0                              ; Drive 9 direction | Front Left Z
    ;Extruders
    
    M569 P1 S0                              ; Drive 1 direction | Extruder0
    M569 P2 S0                              ; Drive 2 direction | Extruder1
    M569 P3 S0                              ; Drive 3 direction | Extruder2
    M569 P4 S0                              ; Drive 4 direction | Extruder3
    
    ;Toolchanger actuator
    M569 P0 S1				; Drive 0 direction | Toolchanger Actuator
    
    M584 X6 Y5 Z7:8:9 U0 E1:2:3:4                        ; set drive mapping
    M671 X-28:172:458 Y146:402:146 S15 ; leadscrews at front left, rear middle and front right
    
    M350 X16 Y16 Z16 E16 U4 I1                 ; configure microstepping with interpolation
    M92  X80.00 Y80.00 Z400.00 E420.00 U20   ; set steps per mm
    M566 X900.00 Y900.00 Z12.00 E120.00 U350    ; set maximum instantaneous speed changes (mm/min)
    M203 X6000.00 Y6000.00 Z1500.00 E1200.00 U10000 ; set maximum speeds (mm/min)
    M201 X800 Y800 Z20 E1000 U2500          ; set accelerations (mm/s^2)
    M906 X900 Y900 Z900 E800 U1050 I60            ; set motor currents (mA) and motor idle factor in per cent
    
    ; Axis Limits
    M208 X0 Y0 Z0 S1                        ; set axis minima
    M208 X420 Y380 Z480 S0                  ; set axis maxima
    
    ; Endstops
    M574 U1 S1                           ; Set homing switch configuration for toolchange lock. Both switches should be wired NC and in series.
    M574 X1 Y1 S1                           ; set active low and disabled endstops
    
    ; Z-Probe
    M574 Z1 S2 ; Set endstops controlled by probe
    M558 P1 H5 F120 T3000 ; Set Z probe type to modulated and the dive height + speeds
    G31 P467 X0 Y40 Z1.0 ; Set Z probe trigger value, offset and trigger height
    

    Please help i am stock in this problem for week



  • In bed.g,
    M561 is missing before the first G28
    The last G28 is not needed for X and Y axes, just do G28 Z



  • If the adjustment is in the wrong direction pay attention to the connnection

    and these coordinates must be in the same order as the driver numbers of the associated motors in the M584 command.



  • I think your bed code is causing problems. You only need to probe the three points nearest the leadscrews, not corners or centre; probing as close as possible to the leadscrews will give you the best accuracy. See example here: https://duet3d.dozuki.com/Wiki/Bed_levelling_using_multiple_independent_Z_motors#Section_Example_for_3_motors

    Try:

    G28 ; Home
    G30 P0 X20 Y146 Z-99999 ; Probe near Front Right leadscrew
    G30 P1 X172 Y384 Z-99999 ; Probe near rear leadscrew
    G30 P2 X400 Y146 Z-99999 S3 ; Probe near Front Right leadscrew and calibrate the 3 motors
    G28 ; Home
    

    It's also possible that your Z motors are not connected to the motor driver on the the Duex. You have defined the leadscrew positions with:

    M671 X-28:172:458 Y146:402:146 S15 ; leadscrews at front left, rear middle and front right
    

    but the order you have defined the motors is the other way around:

    ;Z motors
    M569 P7 S0                              ; Drive 7 direction | Front Right Z
    M569 P8 S0                              ; Drive 8 direction | Back Z
    M569 P9 S0                              ; Drive 9 direction | Front Left Z
    

    Check you have connected them correctly.

    Ian



  • Thanks so far i will inform you what was wrong and what I change.

    Thanks Matej O.


Log in to reply