BLTouch G30 troubles



  • I'm pulling my hairs out and would like to ask you for help please.

    Duet3, RRF 3.1.1 with BLTouch 3.1 connected to IO7. Everything is working as expected except when I use G30 S-1 to measure the Z height. BLTouch deploys, measures the height but doesn't retract, is blinking red and keeps in Z-Probe status 1000. Can't figure out what's wrong.

    Screenshot 2020-09-23 at 12.36.11.png

    ; Z-Probe
    M950 S0 C"io7.out"                                       ; create servo pin 0 for BLTouch
    M558 P9 C"^io7.in" R0.5 H5 F300 T3000                    ; set Z probe type to bltouch and the dive height + speeds
    G31 P500 X36.47 Y-4 Z1.030                               ; set Z probe trigger value, offset and trigger height
    M557 X20:330 Y5:300 P5:5                                 ; define mesh grid
    
    ; deployprobe.g
    ; called to deploy a physical Z probe
    ;
    ; generated by RepRapFirmware Configuration Tool v3.1.4 on Mon Aug 10 2020 22:00:50 GMT+0200 (Central European Summer Time)
    M280 P0 S10 ; deploy BLTouch
    
    
    ; retractprobe.g
    ; called to retract a physical Z probe
    ;
    ; generated by RepRapFirmware Configuration Tool v3.1.4 on Mon Aug 10 2020 22:00:50 GMT+0200 (Central European Summer Time)
    M280 P0 S90 ; retract BLTouch
    


  • @MartinNYHC

    Does M401 and M402 work ?
    Are you getting any error messages ?
    Does plain G30 work or do the same thing ?



  • Yes, it is working for homing, leadscrew probing and bed probing but not for G30 S-1.



  • @MartinNYHC

    Doing a long print now so I can't check , I know that G30 s-1 as worked for me in the past , but not sure if I was on 3.1.1 at the time.



  • I'm still looking for a (working) possibility to auto set Z offset. I'm always struggeling with a wrong offset and this is very annoying.


  • Moderator

    @MartinNYHC said in BLTouch G30 troubles:

    M558 P9 C"^io7.in" R0.5 H5 F300 T3000

    Remove the '^' to enable the pullup resistor. Because, as @dc42 says here https://forum.duet3d.com/post/179301

    All Duet 3 ioX.in ports have permanent pullup resistors, on the main board and on expansion boards. So you never need to use ^ in the name. We recommend that you do not, because enabling it reduces the noise margin.

    F300 is quite fast for BLTouch probing, so it's possible that it's knocking the pin back in too hard. Try experimenting with the feed rate to see if that helps.

    Not sure why it would have an issue with G30 S-1, but not with other probing, with either of the above.

    Ian



  • Enabled pullup resistor and changed to F100. Same problem.



  • check your wiring. the cables that come with the bltouch are notoriously bad.

    you should never see 1000 in the webui when using a bltouch.



  • Already checked the cables and they are good. Remember that the BLTouch is onky having problems with G30 S-1 and NOT with homing, bed and leadsrew probing. Very strange.



  • @MartinNYHC

    I'm still looking for a (working) possibility to auto set Z offset.

    That is the point of the bltouch that if you change the beds height it will compensate.
    But you still need to set the distance between the nozzle to the bed unless to have a metallic bed and nozzle a test a short or a physical switch with nozzle contact .


  • Moderator

    Can you send M98 P"config.g" and report any errors?

    How exactly are you going through the G30 S-1 process?

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

    I use a macro to help automate the process, see here:

    M291 P"Grid bed compensation map and Z Probe trigger height will be cleared. Ok or Cancel?" R"WARNING" S3 ; User must click OK or cancel.
    M291 P"Heights will be found in gcode console if logging successful gcode is enabled" R"Did you remember to enabled gcode logging?" S3
    
    ; Clear compensation map and Z probe trigger height
    ;
    G28			; home all axis
    M561			; Disable any current bed compensation
    G90			; Absolute positioning
    T0			; Activate first tool
    M98 P"ZSpeedsSlow.g"	; Set lower speeds for Z homing and lower Z motor current
    M913 Z50		; Drop motor current to prevent damage in case of head crash
    
    ; Preheat to probing temps
    ;
    M291 P"Preheating to bed to 60 and nozzle to 210 for accurate probing"
    M104 S210		; Set nozzle to 210 and release
    M190 S60		; Set bed to 60 and wait
    M109 S210		; Set nozzle to 210 and wait
    
    M98 P"0:/macros/musical tunes/GetAttention.g"
    
    ; 1
    ;
    M291 P"Nozzle will now move to center of bed to reset Z0 and calibrate probe" S3
    M98 P"0:/macros/Calibration/Bed Leveling/1_Center Nozzle on Bed"
    G90 G1 Z3 F400
    M400
    G92 Z4 			; Reset z to 8 to allow jogging up to touch bed to nozzle
    M291 P"Jog the Z Axis until the bed and nozzle are touching and click OK" R"Setting Z=0" Z1 S3
    M400
    G92 Z0			; Set z = 0
    G90 G1 Z3 F400
    M104 S0 		; Turn off hotend heater as it's no longer needed
    M291 P"Probe will now move to center of bed and measure trigger height 10 times" R"ZProbe Trigger Height Calibration" T3
    M400
    M98 P"0:/macros/Calibration/Bed Leveling/1_Center Probe on Bed"
    
    G1 Z5
    M400
    G30 S-1
    M400
    G1 Z5
    M400
    G30 S-1
    M400
    G1 Z5
    M400
    G30 S-1
    M400
    G1 Z5
    M400
    G30 S-1
    M400
    G1 Z5
    M400
    G30 S-1
    M400
    G1 Z5
    M400
    G30 S-1
    M400
    G1 Z5
    M400
    G30 S-1
    M400
    G1 Z5
    M400
    G30 S-1
    M400
    G1 Z5
    M400
    G30 S-1
    M400
    G1 Z5
    M400
    G30 S-3 ; measure probe height and set it.
    M400
    M500 P31 ; save trigger height to config-override.g
    G1 Z5
    
    M98 P"0:/macros/musical tunes/GetAttention.g"
    
    ; Turn off heaters
    ; 
    M104 S0		; Set nozzle to 0 and release
    M140 S0		; Set bed to 0 and release
    M98 P"ZSpeedsNormal.g"	; return to normal speeds
    M98 P"CurrentsNormal.g"
    M400
    M291 P"Homing"
    G28		; Home Z
    M84 ; turn off the motors
    M291 P"Probing complete. Turning off heaters and homing axis. Check log for trigger heights and enter into config.g" S2
    


  • @Phaedrux There are no erros when doing a M98 P"config.g". The interesting thing is, that you macro works without any error 😉 Don't ask me why. Will do some tests to see how it goes. Thanks for sharing your macro!



  • @Phaedrux Thanks again! for your macro. It does exactly what I was looking for and is going to be part of my new workflow 🙂


  • Moderator

    @MartinNYHC I'm glad it worked out for you. It calls some macros to move to positions and set some values, so you may want to edit it to use your specific values.



  • @Phaedrux said in BLTouch G30 troubles:

    @MartinNYHC I'm glad it worked out for you. It calls some macros to move to positions and set some values, so you may want to edit it to use your specific values.

    Already changed it to my needs 😉


Log in to reply