Trigger height not taking effect on Delta printer.



  • Hi there,

    I am transitioning to a Duet 2 Wifi on my Kossel Delta printer (Linear Plus). I am getting close to what I thing is a working firmware. I have run the Delta calibration as well as the G29 for bed compensation. I changed the M665 values on config.g for those shown after delta calibration.
    As I often do in these situations, I approach the nozzle to the bed in a step wise manner, in order not to damage the bed is something goes south. The value of trigger height is copy-pasted from the Marlin file but changing the sign. From -16.10 on Marlin Z-Probe offset to +16.10 on the G31 command on the Duet (the actual + sign is not there, fear not).
    Although the nozzle goes quite close to the bed, it is still aprox 0.15mm too far above.
    Now, my gut instinct told me to just change the Z value on the G31 command to Z16.25. I did so, save and reset, try it again, but nothing changed. The nozzle is still 0.15mm above the bed. Just in case, I tried changing to G31 Z15.95 and still the same...
    I am now what one could considered as "lost". Could somebody give me a hand? Am I missing something? Do I have to re-calibrate and run the G29 all over again?

    I have a Duet 2 WiFi (1.04 I believe), running the latest stable release (2.03, I think).

    My config file is as follows (still some work left to do such as PID calibration):

    Thanks in advance

    ; Configuration file for Duet WiFi (firmware version 1.20 or newer)
    ; executed by the firmware on start-up
    ;
    ; 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
    
    ; After G32 auto-calibrate, copied from config-override.g
    ; Note: G31 Z (below) affects M665 H, and this is NOT yet calibrated.
    
    M665 L267.0 R132.408 H301.206 B106.0 X-0.232 Y0.064 Z0.0      ; Set delta radius, diagonal rod length, printable radius and homed height
    M666 X-0.14 Y-0.17 Z0.32 A0.00 B0.00                      ; Put your endstop adjustments here, or let auto calibration find them
    
    
    ; Network
    M550 P"Kossel"                                     ; Set machine name
    M552 S1                                            ; Enable network
    ;*** 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 goes forwards
    M569 P1 S0                                         ; Drive 1 goes forwards
    M569 P2 S0                                         ; Drive 2 goes forwards
    M569 P3 S1                                         ; Drive 3 goes forwards
    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 I50                   ; 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 P4 H5 F120 T6000                              ; Set Z probe type to switch and the dive height + speeds
    G31 P1000 X0 Y0 Z15.95                             ; Set Z probe trigger value, offset and trigger height
    M557 R105 S20                                      ; Define mesh grid
    
    ; Heaters
    M307 H0 B0 S1.00                                   ; Disable bang-bang mode for the bed heater and set PWM limit
    M305 P0 T100000 B4267 C0 R4700                     ; Set thermistor + ADC parameters for heater 0
    M143 H0 S120                                       ; Set temperature limit for heater 0 to 120C
    M305 P1 T100000 B4267 C0 R4700                     ; Set thermistor + ADC parameters for heater 1
    M143 H1 S280                                       ; Set temperature limit for heater 1 to 280C
    
    ; 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
    
    


  • @FelixH said in Trigger height not taking effect on Delta printer.:

    Now, my gut instinct told me to just change the Z value on the G31 command to Z16.25

    Not quite. Its determined by the H Parameter in M665 (the other parameter also affect it)
    i would recommend to just run the delta calibration again after changing the offset.

    follow this to find the actual offset
    https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe



  • @Veti nailed it. H is total from limit switches down to zero, and the nozzle won't (normally) go "below zero".

    Re-run, get H right, and continue your stepwise approach.



  • @FelixH said in Trigger height not taking effect on Delta printer.:

    I have a Duet 2 WiFi (1.04 I believe), running the latest stable release (2.03, I think).

    please update to 2.04 RC latest. there is a delta bug in 2.03



  • Just after I hit the "Submit" button I thought about it but felt conflicted about it...

    Thanks for your pointers also regarding to update to the 2.04RC. I'll keep you apprised about my progress...

    The update to 2.04RC should it be to 2.04RC4 ??

    BTW... should I repeat the G29 also?



  • Well, I did change the trigger height to 16.25 and re-run the delta calibration. The Delta Height changed by 0.2mm (or so). I approached the nozzle to the bed until Z=0 and, sure enough, I got nice paper grab...

    Thanks a lot, everybody


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