1.19+1 Z offset issues

  • Hi,

    I've just been upgrading from 1.18 and I can't get my duet wifi running 1.19+1 to use the Z probe offset from the G31 commands in both config and config-override.
    The only way to have the correct Z offset is to use the z baby stepping.

    G31 T1 does report the Z offset I have configured.
    I need to 5 z baby steps (up) to get a proper first layer, so I have added the 0.25mm to my G31 but I still get bad first layer and I still need 5 steps to get a correct one.
    I have also tried with G31 Z10 … and i still need the baby steps.

    There's something I don't really get here, what am I missing ?

    here are my configs:

     Configuration file for T3P3 Kossel XL Kit with Duet WiFi
    ; Communication and general
    M111 S0					; Debug off
    M550 PKosselXL				; Machine name (can be anything you like)
    M551 Preprap				; Machine password (used for FTP)
    ; M540 P0xBE:0xEF:0xDE:0xAD:0xFE:0x42	; MAC Address - not for WiFi
    ; Not for WiFi *** Adjust the IP address and gateway in the following 2 lines to suit your network
    ; M552 P0.0.0.0				; IP address (0 = use DHCP)
    ; M554 P192.168.0.254			; Gateway
    ; M553 P255.255.255.0			; Netmask
    M555 P2					; Set output to look like Marlin
    ; M575 P1 B57600 S1			;No longer required: Set auxiliary serial port baud rate and require checksum (for PanelDue)
    ; For WiFi only
    M552 S1					; Start WiFi
    ; Axis and motor configuration
    M569 P0 S0				; Drive 0 goes forwards
    M569 P1 S0				; Drive 1 goes forwards
    M569 P2 S0				; Drive 2 goes forwards
    M569 P3 S1				; Drive 3 goes forwards
    M569 P4 S0				; Drive 4 goes forwards
    M574 X2 Y2 Z2 P1			; set endstop configuration (all endstops at high end, active high)
    ; NOTE: Homed height H is deliberately set too high in the next line. You will measure and set it during calibration
    M665 R176.711 L350 B125 H382.468 X0.110 Y-0.421	; set delta radius R, diagonal rod length L, printable radius B, homed height H and XY tower corrections
    M666 X0.13 Y0.69 Z-0.82				; Use autocalibration to find your endstop adjustments and enter them here
    M92 X160 Y160 Z160			; Set axis steps/mm (20 tooth pulleys, 0.9deg/step motors)
    M906 X1360 Y1360 Z1360 E600		; Set motor currents (mA)
    M201 X3000 Y3000 Z3000 E1000		; Accelerations (mm/s^2)
    M203 X18000 Y18000 Z18000 E3600		; Maximum speeds (mm/min)
    M566 X600 Y600 Z600 E600		; Maximum instant speed changes
    G21					; Work in millimetres
    G90					; Send absolute coordinates...
    M83					; ...but relative extruder moves
    ; Thermistors and heaters
    M143 S275				; Set maximum hotend temperature to 275 C - default is 262
    M305 P0 T100000 B3950 R4700 H0 L0	; Typical Chinese bed thermistor. Put your own H and/or L values here to set the bed thermistor ADC correction.
    M305 P1 T100000 B4388 R4700 H0 L0	; E3Dv6 hot end. Put your own H and/or L values here if necessary to set the first nozzle thermistor ADC correction.
    ; M301 H0 P20 I0.5 D1000 T0.85 W150 B5	; PID settings for the bed
    ; M301 H1 P11.1 I0.06 D38.8		; Legacy PID settings for extruder 0.
    ; See https://duet3d.com/wiki/Tuning_the_heater_temperature_control for how to run autotuning on the hotend to derive the parameters below.
    M307 H0 A130.7 C579.5 D8.8 B0
    M307 H1 A473.7 C163.0 D4.7 B0
    ;M307 H1 A596.9 C185.5 D5.0 B0		; Measured heating process parameters for E0 = E3D V6 with 24V 40W cartridge, using autotuning
    M570 S200				; Allow extra heating time
    ; Tool definitions
    M563 P0 D0 H1				; Define tool 0
    G10 P0 S0 R0				; Set tool 0 operating and standby temperatures
    ;M92 E421				; Set extruder steps per mm
    M92 E405
    ; thermostatic fan1
    M106 P1 T45 H1
    ; Z probe and compensation definition
    M558 P1 X0 Y0 Z0 H3 F300 T12000		; Z probe is IR and is not used for homing any axes, Z probe dive height 3mm, probing speed 300mm/min, travel speed 12000mm/min
    G31 X0 Y0 Z1.66 P500			; Set the zprobe offset and threshold. For a delta, use zero X and Y offset and measure Z offset.
    ;*** If you are using axis compensation, put the figures in the following command
    ; M556 S78 X0 Y0 Z0			; Axis compensation here
    ; M207 S7.0 F3600 Z0.1			; Set firmware retraction details. Comment out pending more info
    ; M572 D0 S0.1				; set pressure advanc.  Comment out pending more info
    M557 R100 S20
    S29 S1
    T0					; select first print head
    ; This is a system-generated file - do not edit
    ; Delta parameters
    M665 L350.000 R176.842 H382.633 B125.0 X-0.086 Y-0.476 Z0.000
    M666 X0.192 Y0.648 Z-0.840 A0.00 B0.00
    ; Heater model parameters
    M307 H0 A130.7 C579.5 D8.8 S1.00 B0
    M307 H1 A473.7 C163.0 D4.7 S1.00 B0
    M307 H2 A340.0 C140.0 D5.5 S1.00 B0
    M307 H3 A340.0 C140.0 D5.5 S1.00 B0
    M307 H4 A340.0 C140.0 D5.5 S1.00 B0
    M307 H5 A340.0 C140.0 D5.5 S1.00 B0
    M307 H6 A340.0 C140.0 D5.5 S1.00 B0
    M307 H7 A340.0 C140.0 D5.5 S1.00 B0
    ; Z probe parameters
    G31 T1 P500 X0.0 Y0.0 Z1.66
    G31 T3 P500 X0.0 Y0.0 Z0.70
    G31 T4 P500 X0.0 Y0.0 Z0.00

  • I have a similar problem trying to apply a negative offset for the smart effector probe

  • 1 are you loading the config override back in each time with a M501 if not then any change you make is not being remembered try putting the G31 Z0.15 at the end of your Config.g |(with the other parameters) so something like

    G31 P100 X0 Y0 Z0.15

    then adjust the Z Value in the Config.g to suit your own circumstances (I have assumed the Smart effector with that line it may well be different for the OP for the IR Probe the P would be 500 and the Z somewhat larger and you need to find the difference in hight of the nozzle and the probe trigger.

  • Hi,
    I have updated my post with the complete config.g, i'm using M501.
    anyway, both config.g and config-override.g contain the same G31 settings, and I still need the baby steps…

  • tried again and again with Z16.6 in both config files, still need 5 baby steps up to get a proper 1st layer.

  • OK so your G31 is telling the firmware that the nozzle 1.66 mm above the bed when the probe triggers and you nee to babystep up 5 to get a good first layer so set the Z param in your G31 to 1.41 this should lift your Z0 by 0.25 mm or 5 babysteps.


  • whether I substract or add the .25mm to the Z offset in my G31 I still have to use 0.25mm of baby stepping !
    (also tried to add/substract 1mm to make sure I could see a difference, there's none)
    that's doing my head in 🙂
    I guess I'll end-up adding the baby steps with M290 in my config until someone comes up with a way to help me diagnostic/solve this issue.

  • But your M501 is overwriting it you need to clear out the G31 parts of the Config-Overide file or clear totally by either deleting it entirely or running M502. Make sure you copy any M665 M666 and M307 lines into your Config.g First

  • M501 in config, I'm changing the G31 in the override.
    or I do the G31 in console and then M500.
    and then I check with G31 T1

    I've just edited my previous post, I guess I'll end-up adding the baby steps with M290 in my config until someone comes up with a way to help me diagnostic/solve this issue.

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