BLTouch XY offset problems



  • I have converted my old A8 into an AM8 and turned to the Duet Wifi for a new controller board from RAMPS.

    Now, I wanted to use the BLtouch for bed leveling.

    So far, so good. Everything works.

    Not the BLtouch bed leveling...

    I get the BLtouch to work nicely and consistently. When not trying to get a Mesh of the bed.

    When I try to run a full 'Auto Bed Compensation', it moves to the X center of the bed and stops two millimeters in front of the bed (Y axis) and tries to level (which incidentally trashed two Z endstop switches).

    When I try to compensate for it with the Y axis offset by making it larger, it stops further from the Y axis bed. It I try to compensate by making the Y offset smaller, it does not even move to the center of the X axis...

    Here is the config.g and an image of the position of the BLtouch when trying to run G29...

    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool v2 on Wed Jan 30 2019 16:08:54 GMT+0100 (Central European Standard Time)
    
    ; General preferences
    G90                                      ; Send absolute coordinates...
    M83                                      ; ...but relative extruder moves
    
    ; Network
    M550 P"printbot"                         ; Set machine name
    M551 P"xxxxxxxxxxxxxx"                         ; Set password
    M552 S1                                  ; Enable network
    M587 S"xxxxxxxxxxx" P"xxxxxxxxxxx"           ; Configure access point. You can delete this line once connected
    M586 P0 S1                               ; Enable HTTP
    M586 P1 S0                               ; Disable FTP
    M586 P2 S0                               ; Disable Telnet
    
    ; Drives
    M569 P0 S1                               ; Drive 0 goes forwards
    M569 P1 S1                               ; Drive 1 goes forwards
    M569 P2 S0                               ; Drive 2 goes backwards
    M569 P3 S0                               ; Drive 3 goes forwards
    M350 X16 Y16 Z16 E16 I1                  ; Configure microstepping with interpolation
    M92 X79.71 Y79.94 Z402.09 E95        ; Set steps per mm
    M566 X600.00 Y600.00 Z18.00 E300.00      ; Set maximum instantaneous speed changes (mm/min)
    M203 X12000.00 Y12000.00 Z360.00 E6000.00  ; Set maximum speeds (mm/min)
    M201 X1500.00 Y1500.00 Z100.00 E10000.00 ; Set accelerations (mm/s^2)
    M906 X750.00 Y750.00 Z750.00 E800.00 I30 ; Set motor currents (mA) and motor idle factor in per cent
    M84 S30                                  ; Set idle timeout
    
    ; Axis Limits
    M208 X-27 Y-10 Z0 S1                     ; Set axis minima
    M208 X220 Y190 Z240 S0                   ; Set axis maxima
    
    ; Endstops
    M574 X1 Y1 Z1 S0                         ; Set active low and disabled endstops
    
    ; Z-Probe
    M307 H3 A-1 C-1 D-1                      ; Disable heater on PWM channel for BLTouch
    M558 P9 H5 F100 T6000 A10 R0.5 S0.008    ; Set Z probe type to bltouch and the dive height + speeds
    G31 P500 X37 Y32 Z2.3                    ; Set Z probe trigger value, offset and trigger height
    M557 X20:200 Y20:200 S40                 ; Define mesh grid
    
    ; Heaters
    M307 H0 B0 S1.00                         ; Disable bang-bang mode for the bed heater and set PWM limit
    M305 P0 T100000 B4388 C7.060000e-8 R4700 ; Set thermistor + ADC parameters for heater 0
    M143 H0 S130                             ; Set temperature limit for heater 0 to 130C
    M305 P1 T100000 B4388 C7.060000e-8 R4700 ; Set thermistor + ADC parameters for heater 1
    M143 H1 S275                             ; Set temperature limit for heater 1 to 275C
    
    ; Fans
    M106 P0 S1 I0 F500 H1 T45                ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned on
    M106 P1 S1 I0 F500 H-1                   ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off
    M106 P2 S1 I0 F500 H-1                   ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned off
    
    ; 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 saving after power loss is not enabled
    
    ; Custom settings are not configured
    
    ; Miscellaneous
    T0                                       ; Select first tool
    

    alt text



  • Looks to me, that your probe is in front and left from nozzle, so in - direction in both x and y. Probe offset is from nozzle to probe, so i guess in G31 command X and Y should be negative, X-37 and Y-32.



  • Certainly worth a try...

    EDIT:

    Thanks...

    Sometimes its the simple things you don't see... >_>


 

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