Z Offset



  • I am trying to calibrate my Orion Piezo with a Duet WiFi, I am following the instructions here “https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe#Section_Calibrate_the_Z_probe_trigger_height” for Calibrating the Z probe trigger height however I am unsure what am I doing wrong. After following the instructions I come up with a trigger height of “-0.177 mm” I did entered it in the config.g file do a reboot and when I do a G31 in the console it reports as “G31 Current reading 0, threshold 100, trigger height -0.18, offsets X0.0 Y0.0” all good there. I do an “Auto Delta Calibration” all completes correctly, home the machine and lower the nozzle to the bed to a sheet of paper, I still got 4.04mm to go and the nozzle is already contacting the page snug where I can hardly move it. It does not matter how many times I calibrate with “Auto Delta Calibration” or “Mesh Grid Compensation” still there is too much Z travel, I checked my config-override.g but I do not see a G31 I can only find one in config.g. Could you folks please let me know what am I doing wrong? Thank you!

    Config.g ===========================================

    ; Configuration file for Duet WiFi (firmware version 2.03)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool v2.0.0 on Sat Aug 31 2019 17:47:12 GMT-0700 (Pacific Daylight Time)

    ; General preferences
    M111 S0 ; Debug off
    G90 ; send absolute coordinates...
    M83 ; ...but relative extruder moves
    M550 P"ID" ; set printer name
    M665 L293.714:293.714:293.714 R130.433 H370.142 B100.0 X1.108 Y0.356 Z0.000
    M666 X-0.610 Y0.392 Z0.218 A0.00 B0.00
    ; automatic saving on power loss is not configured

    ; Drives
    M569 P0 S1 ; physical drive 0 goes forwards X
    M569 P1 S1 ; physical drive 1 goes forwards Y
    M569 P2 S1 ; physical drive 2 goes forwards Z
    M569 P3 S1 ; physical drive 3 goes forwards E0
    M584 X0 Y1 Z2 E3 ; set drive mapping
    M350 X16 Y16 Z16 E16 I1 ; configure microstepping with interpolation
    M92 X100.00 Y100.00 Z100.00 E439.153 ; set steps per mm
    M566 X1200.00 Y1200.00 Z1200.00 E1200.00 ; set maximum instantaneous speed changes (mm/min)
    M203 X18000.00 Y18000.00 Z18000.00 E1200.00 ; set maximum speeds (mm/min)
    M201 X1000.00 Y1000.00 Z1000.00 E1000.00 ; set accelerations (mm/s^2)
    M906 X1200 Y1200 Z1200 E1000 I30 ; set motor currents (mA) and motor idle factor in per cent
    M84 S30 ; Set idle timeout

    ; Axis Limits
    M208 Z0 S1 ; set minimum Z

    ; Endstops
    M574 X2 Y2 Z2 S1 ; set active high endstops

    ; Z-Probe
    M558 P5 I1 R0. 4 F300 X0 Y0 Z0
    G31 X0 Y0 Z-0.177 P100 ; Default for Z-0.1
    M557 R85 S20 ; define mesh grid

    ; Heaters
    M305 P0 T100000 B4700 ; set thermistor + ADC parameters for heater 0
    M143 H0 S130 ; set temperature limit for heater 0 to 120C
    M305 P1 R4700 T100000 B3950 ; set bed thermistor parameters
    M143 H1 S300 ; set temperature limit for heater 1 to 280C
    M307 H1 A350.2 C218.1 D8.7 S1 V12.5 B0

    ; Fans
    M106 P0 S0 I0 F500 H-1 ; set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
    M106 P1 S1 I0 F500 H1 T45 ; set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on

    ; Tools
    M563 P0 S"HotEnd" D0 H1 F0 ; define tool 0
    G10 P0 X0 Y0 Z0 ; set tool 0 axis offsets
    G10 P0 R0 S0 ; set initial tool 0 active and standby temperatures to 0C

    ; Network
    M552 S1 ; enable network
    M586 P0 S1 ; enable HTTP
    M586 P1 S0 ; disable FTP
    M586 P2 S0 ; disable Telnet

    ; Custom settings are not defined

    ; Miscellaneous
    T0 ; select first tool
    M564 H0
    M501 ;Re-load M665 and M666 commands in config-override.g on reset/powerup

    Config-override.g====================================================

    ; config-override.g file generated in response to M500 at 2019-10-03 22:31
    ; This is a system-generated file - do not edit
    ; Delta parameters
    M665 L293.714:293.714:293.714 R130.433 H370.142 B100.0 X1.108 Y0.356 Z0.000
    M666 X-0.610 Y0.392 Z0.218 A0.00 B0.00
    ; Heater model parameters
    M307 H0 A90.0 C700.0 D10.0 S1.00 V0.0 B1
    M307 H1 A350.2 C218.1 D8.7 S1.00 V12.5 B0
    M307 H2 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H3 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H4 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H5 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H6 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H7 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    G10 L2 P1 X0.00 Y0.00 Z0.00
    G10 L2 P2 X0.00 Y0.00 Z0.00
    G10 L2 P3 X0.00 Y0.00 Z0.00
    G10 L2 P4 X0.00 Y0.00 Z0.00
    G10 L2 P5 X0.00 Y0.00 Z0.00
    G10 L2 P6 X0.00 Y0.00 Z0.00
    G10 L2 P7 X0.00 Y0.00 Z0.00
    G10 L2 P8 X0.00 Y0.00 Z0.00
    G10 L2 P9 X0.00 Y0.00 Z0.00

    homedelta.g==============================================

    ; homedelta.g
    ; called to home all towers on a delta printer
    ;
    ; generated by RepRapFirmware Configuration Tool v2.0.0 on Sat Aug 31 2019 17:47:12 GMT-0700 (Pacific Daylight Time)
    G91 ; relative positioning

    G1 S1 X375 Y375 Z375 F4000 ; move all towers to the high end stopping at the endstops (first pass)
    G1 X-5 Y-5 Z-5 F1800 S2 ; go down a few mm
    G1 S1 X10 Y10 Z10 F360 ; move all towers up once more (second pass)
    G1 Z-5 F6000 ; move down a few mm so that the nozzle can be centred <<<<<<<<<<<<<<<<<<
    G90 ; absolute positioning
    G1 X0 Y0 F6000 ; move X+Y to the centre <<<<<<<<<<<<<<<<



  • Well I think I figured it out, if I do a "Disable Mesh Grid Compensation" G29 S2 I think it makes it work, I do not understand why that seems to work, I would have thought that Mesh Grid Compensation would have helped not make things break. Could someone please shed some light I am confused.


  • administrators

    @Recoil

    Its worth reading this documentation:

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

    and then specifically this for a delta printer:

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

    You should get the z probe working, then get the delta calibration accurate, then add mesh bed levelling at the end to iron out any issues with the bed not being flat.



  • Hi T3P3Tony,
    l already read both of them, what was weird is that after following instructions setting the Z offset it wouldn't take as I mention I had to Disable Mesh Grid Compensation to make it work and I do not know why, I would have thought it sets correctly every time I run it.


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