Anycubic Kossel Plus adjusting final z-offset



  • I've just upgraded the hotend from the anycubic e3d clone to a real E3D v6 lite. Before the upgrade, be leveling, etc. worked fine and the mechanical probe, how it's attached, etc. are exactly the same and I can do mesh leveling just fine.

    What has changed, is the position of the nozzle as the V6 is a bit shorter than the stock hotend was. As a result, the nozzle is now 0.85 mm too high, which I can easily adjust at the start of the print by setting the z-babystepping to -0.85 mm. But, I would like to put this 0.85 mm offset into my config, so I don't have to set it manually. Question is - how?

    I feel a bit silly asking for help with this seemingly simple adjustment but I didn't find it looking a similar posts. Also, I'm not fully clear on how all this bed leveling stuff really works (worked it out 2 years ago and then forgot) and now I'm hesitant to start changing stuff and risk screwing up my otherwise perfectly serviceable setup.

    Can somebody point me to what value(s) I need to adjust to lower the nozzle by 0.85 mm ?

    Thanks in advance!

    Here are my config files:

    ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
    config.g
    ; generated by RepRapFirmware Configuration Tool on Thu Jul 12 2018 20:54:00 GMT-0500 (Central Daylight Time)
    
    ; General preferences
    G90                                                ; Send absolute coordinates...
    M83                                                ; ...but relative extruder moves
    
    ; Without calibration
    M665 L268.031:268.031:268.031 R134.201 H295 B120.0                      ; Set delta radius, diagonal rod length, printable radius and homed height
    M666 X0 Y0 Z0                                      ; Put your endstop adjustments here, or let auto calibration find them
    
    
    
    ;*** The homed height is deliberately set too high in the following - you will adjust it during calibration.
    
    
    ; with 6,7,8 params https://duet3d.dozuki.com/Wiki/Calibrating_a_delta_printer#Section_Setting_up_the_bed_g_file
    M665 L268.031:268.031:268.031 R133.912 H290.834 B105.0 X-0.770 Y0.406 Z0.000
    M666 X0.692 Y-1.982 Z1.290 A-0.19 B-0.51
    
    M665 B110 ; bed radius is 11 cm!
    
    ; Network
    <hidden>
    
    
    
    ;*** Access point is configured manually via M587
    M586 P0 S1                                         ; Enable HTTP
    M586 P1 S0                                         ; Disable FTP
    M586 P2 S0                                         ; Disable Telnet
    
    ; Drives
    M569 P0 S0                                         ; Drive 0 reversed
    M569 P1 S0                                         ; Drive 1  reversed
    M569 P2 S0                                         ; Drive 2  reversed
    M569 P3 S0                                         ; Drive 3 reversed
    M350 X16 Y16 Z16 E16 I1                            ; Configure microstepping with interpolation
    M92 X80 Y80 Z80 E96                                ; Set steps per mm
    M566 X300 Y300 Z300 E300                           ; Set maximum instantaneous speed changes (mm/min)
    M203 X12000 Y12000 Z12000 E12000                   ; Set maximum speeds (mm/min)
    M201 X3000 Y3000 Z3000 E3000                       ; Set accelerations (mm/s^2)
    M906 X1000 Y1000 Z1000 E1000 I30                   ; Set motor currents (mA) and motor idle factor in per cent
    M84 S30                                            ; Set idle timeout
    
    ; Axis Limits
    M208 Z-1 S1                                         ; Set minimum Z
    
    ; Endstops
    M574 X2 Y2 Z2 S1                                   ; Set active high endstops
    
    ; Z-Probe
    M558 P4 H2 F300 T8000                        ; Set Z probe type to switch and the dive height + speeds  
    G31 P1000 X0 Y0 16.67              ; Set Z probe trigger value, offset and trigger height, was 16.67 before V6
    M557 R110 S20                                      ; Define mesh grid
    
    ; Filament sensor
    M591 D0 P2 C4 S1 ; P2: low signal when filament present), C4: connect to E1 endstop
    
    ; Heaters
    M305 P0 T100000 B4138 C0 R4700                     ; Set thermistor + ADC parameters for heater 0
    M143 H0 S120                                       ; Set temperature limit for heater 0 to 120C
    M305 P1 T100000 B4729 C7.06e-8 R4700               ; Set thermistor + ADC parameters for heater 1 # E3D V6 lite 
    M143 H1 S250                                       ; Set temperature limit for heater 1 to 250C
    ; PID tune: Heater 1 model: gain 321.9, time constant 165.8, dead time 6.4, max PWM 1.00, calibration voltage 12.9, mode PID, inverted no, frequency default
    Computed PID parameters for setpoint change: P14.4, I0.441, D64
    ; set via config override
    
    
    ; Fans
    M106 P0 S0.3 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
    M106 P2 S1 I0 F500 H1 T45                          ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on
    
    ; Tools
    M563 P0 D0 H1                                      ; 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
    
    ; Automatic power saving
    M911 S10 R11 P"M913 X0 Y0 G91 M83 G1 Z3 E-5 F1000" ; Set voltage thresholds and actions to run on power loss
    
    ; Custom settings are not configured
    
    ; Miscellaneous
    M501                                               ; Load saved parameters from non-volatile memory
    T0                                                 ; Select first tool
    

    ; bed.g
    ; called to perform automatic delta calibration via G32
    ;
    ; generated by RepRapFirmware Configuration Tool on Thu Jul 12 2018 20:54:00 GMT-0500 (Central Daylight Time)
    M561 ; clear any bed transform
    G28  ; home all towers
    ; Probe the bed at 6 peripheral and 3 halfway points, and perform 6-factor auto compensation
    ; Before running this, you should have set up your Z-probe trigger height to suit your build, in the G31 command in config.g.
    G30 P0 X0 Y110 H0 Z-99999
    G30 P1 X95.25 Y55 H0 Z-99999
    G30 P2 X95.26 Y-55 H0 Z-99999
    G30 P3 X0 Y-100 H0 Z-99999
    G30 P4 X-95.25 Y-55 H0 Z-99999
    G30 P5 X-95.26 Y55 H0 Z-99999
    G30 P6 X0 Y55 H0 Z-99999
    G30 P7 X47.63 Y-27.5 H0 Z-99999
    G30 P8 X-47.63 Y-27.5 H0 Z-99999
    G30 P9 X0 Y0 H0 Z-99999 S8 ;https://duet3d.dozuki.com/Wiki/Calibrating_a_delta_printer#Section_Setting_up_the_bed_g_file
    M500 P31 ; save to override
    

    config-override:

    ; config-override.g file generated in response to M500
    ; This is a system-generated file - do not edit
    ; Delta parameters
    M665 L268.031:268.031:268.031 R134.002 H289.448 B105.0 X-1.015 Y0.357 Z0.000
    M666 X0.903 Y-1.256 Z0.353 A0.04 B-1.43
    ; Heater model parameters
    M307 H0 A90.0 C700.0 D10.0 S1.00 V0.0 B1
    M307 H1 A321.9 C165.8 D6.4 S1.00 V12.9 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
    ; Z probe parameters
    G31 T1 P500 X0.0 Y0.0 Z0.70
    G31 T3 P500 X0.0 Y0.0 Z0.70
    G31 T4 P1000 X0.0 Y0.0 Z16.20
    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; config-override.g file generated in response to M500
    ; This is a system-generated file - do not edit
    ; Delta parameters
    M665 L268.031:268.031:268.031 R134.002 H289.448 B105.0 X-1.015 Y0.357 Z0.000
    M666 X0.903 Y-1.256 Z0.353 A0.04 B-1.43
    ; Heater model parameters
    M307 H0 A90.0 C700.0 D10.0 S1.00 V0.0 B1
    M307 H1 A321.9 C165.8 D6.4 S1.00 V12.9 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
    ; Z probe parameters
    G31 T1 P500 X0.0 Y0.0 Z0.70
    G31 T3 P500 X0.0 Y0.0 Z0.70
    G31 T4 P1000 X0.0 Y0.0 Z16.20
    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
    


  • @CHarding said in Anycubic Kossel Plus adjusting final z-offset:

    G31 P1000 X0 Y0 16.67 ; Set Z probe trigger value, offset and trigger height, was 16.67 before V6

    subract the value from 16.67, but there is a z missing in front of it.

    M500 P31 ; save to override

    you are saving the G31 offset in you config overwrite. adjust the G31 command there.

    M558 P4 H2 F300 T8000 ; Set Z probe type to switch and the dive height + speeds

    normally you connect the probe to the z probe header and use P8

    btw i replaced the anyubic probe with this.
    https://de.aliexpress.com/item/32968709878.html
    its easier to work with.



  • First of all: Vielen Dank!
    But I'm unclear on most of the steps you seem to suggest and need some more guidance ...

    You said: subtract the value from 16.67

    Step1: changed G31 Z value in config.g to the new smaller value:

    config.g:

    ; Z-Probe
    M558 P4 H2 F300 T8000                        ; Set Z probe type to switch and the dive height + speeds H (was 1.5)
    G31 P1000 X0 Y0 Z15.82              ; Set Z probe trigger value, offset and trigger height, was 16.67 before V6
    M557 R110 S20                                      ; Define mesh grid
    

    You said: "you are saving the G31 offset in you config overwrite. adjust the G31 command there."

    So should I put my G31 into bed.g instead of config.g?

    bed.g:

    ; called to perform automatic delta calibration via G32
    ;
    ; generated by RepRapFirmware Configuration Tool on Thu Jul 12 2018 20:54:00 GMT-0500 (Central Daylight Time)
    M561 ; clear any bed transform
    G28  ; home all towers
    ; Probe the bed at 6 peripheral and 3 halfway points, and perform 6-factor auto compensation
    ; Before running this, you should have set up your Z-probe trigger height to suit your build, in the G31 command in config.g.
    G30 P0 X0 Y110 H0 Z-99999
    G30 P1 X95.25 Y55 H0 Z-99999
    G30 P2 X95.26 Y-55 H0 Z-99999
    G30 P3 X0 Y-100 H0 Z-99999
    G30 P4 X-95.25 Y-55 H0 Z-99999
    G30 P5 X-95.26 Y55 H0 Z-99999
    G30 P6 X0 Y55 H0 Z-99999
    G30 P7 X47.63 Y-27.5 H0 Z-99999
    G30 P8 X-47.63 Y-27.5 H0 Z-99999
    G30 P9 X0 Y0 H0 Z-99999 S8 ;https://duet3d.dozuki.com/Wiki/Calibrating_a_delta_printer#Section_Setting_up_the_bed_g_file
    
    G31 P1000 X0 Y0 Z15.82 ; Set Z probe trigger value
    
    M500 P31 ; save to override
    

    (I know I could just test if this is correct but again I'd rather be sure instead of mess stuff up ....)

    Regarding your suggestion to use the film pressure probe style (https://de.aliexpress.com/item/32968709878.html) instead

    They do look much easier to use but are they precise enough?

    Also, do they wear out with repeated use?



  • @CHarding said in Anycubic Kossel Plus adjusting final z-offset:

    They do look much easier to use but are they precise enough?

    yes precision is good enough.

    try executing
    G31 P1000 X0 Y0 Z15.82
    in the console and save it using M500 P31



  • To get the value of the G31 offset, I use the paper method to get the nozzle where I want above the bed, change my M665 Hxxx height by whatever it I'm off by (increase by the value by the height above Z0 or decrease it by the height below Z0). Home, and do it again to make sure it's consistent. Then I just move the nozzle up by 5mm and do a G30 S-1, it'll spit out the trigger height. Do that a couple times to make sure it's consistent or take the average if I don't want to hunt for the issue. That number it spits out I throw into the G31 Z probe trigger height, so when it calibrates it only takes a baby step during the the start of a print to get the height just right.

    If you want to you can also change the probe speed to lower the variation in trigger height from the probe's response speed. M558 F300 is probably around +/- .01mm variation which ends up with a max of up to .02mm difference in probe measurement just from how fast it responds to the detection. M558 F150 would be +/- .005 mm and M558 F60 would be +/-.002 which is typically smaller than the microsteps at that point.


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