Strange behavior from BLTouch



  • I did a couple prints this morning with no issue. My last print curled on the corners, so I stopped the print, added a larger brim. When I tried to home, the BLTouch did not deploy and the bed rose at travel speed. I stopped it, cycled the duet power and tried again. Same thing. Did not deploy and bed came up at travel speed.

    When I cycled the power, the self test executed properly. I cycled the BLTouch with m401 and m402 and it seemed to work fine, I tried to home again, x and y homed, but the probe did not deploy and bed came up fast again.

    I really don’t think it’s the BLTouch since I don’t think the probe could cause the bed to rise too fast.

    Any ideas?



  • When things don't work, the BLTouch doesn't blink the red light on/off, right? (otherwise it's in an error state).



  • No, it doesn’t blink. Also, I don’t know if this has anything to do with the problem, but if I deploy with M 401, and then trip it with my finger, the pin retracts and then deployed again right away. (That may well be normal behavior, fhough)



  • I don't think that's normal behavior. Once tripped mine stays up.

    What is your firmware version?
    BLTouch version?

    And can you post your config and homing files?



  • Firmware is 2.02
    I do not know how to find the bltouch version

    the config and homing files are below

    ; Configuration file for Duet WiFi (firmware version 1.21)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool v2 on Fri Feb 01 2019 16:04:24 GMT-0500 (Eastern Standard Time)

    ; General preferences
    G90 ; Send absolute coordinates...
    M83 ; ...but relative extruder moves

    M667 S1 ; Select CoreXY mode

    ; Network
    M550 P"Core XY" ; Set machine name
    M552 S1 ; Enable network
    M587 S"BHNDVW3201B4B28_5GEXT" P"3c5d116a" ; 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 S0 ; Drive 0 goes backwards
    M569 P1 S0 ; Drive 1 goes backwards
    M569 P2 S1 ; Drive 2 goes forwards
    M569 P3 S0 ; Drive 3 goes forwards
    M350 X16 Y16 Z16 E16 I1 ; Configure microstepping with interpolation

    M92 X80.5369 Y100.7067 Z399.9219 E416.666 ; Set steps per mm

    M566 X900.00 Y900.00 Z150.00 E857.1428 ; Set maximum instantaneous speed changes (mm/min)
    M203 X18000.00 Y6000.00 Z380.00 E1500.00 ; Set maximum speeds (mm/min)
    M201 X3000.00 Y500.00 Z100.00 E10000.00 ; Set accelerations (mm/s^2)
    M906 X950.00 Y950.00 Z950.00 E950.00 I30 ; Set motor currents (mA) and motor idle factor in per cent
    M84 S30 ; Set idle timeout

    ; Axis Limits
    M208 X0 Y0 Z0 S1 ; Set axis minima
    M208 X300 Y270 Z300 S0 ; Set axis maxima

    ; Endstops
    M574 X1 Y1 Z1 S0 ; Set active low and disabled endstops

    ; Z-Probe
    ;M574 Z1 S2 ; Set endstops controlled by probe
    ;M558 P5 H5 F0 T6000 ; Set Z probe type to switch and the dive height + speeds
    ;G31 P500 X0 Y0 Z0 ; Set Z probe trigger value, offset and trigger height
    ;M557 X15:13 Y15:195 S20 ; Define mesh grid

    ; Heaters
    M305 P0 T100000 B4138 R4700 ; Set thermistor + ADC parameters for heater 0
    M143 H0 S120 ; Set temperature limit for heater 0 to 120C

    M305 P1 T100000 B4725 C7.06e-8 R4700 ; as suggested by Phaedrux
    ;M305 P1 T100000 B4388 C7.06e-8 R4700 ; As suggested by mudcurxzr
    ;M305 P1 T100000 B4138 R4700 ; Set thermistor + ADC parameters for heater 1

    M143 H1 S280 ; Set temperature limit for heater 1 to 280C
    M305 P2 T100000 B4138 R4700 ; Set thermistor + ADC parameters for heater 1
    M143 H2 S280

    ; 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

    ; 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

    ; Attempt to control heater2
    M307 H2 A-1 C-1 D-1 ; Disable Heater E1 for use with the Berd-Air cooling
    M106 P0 A2 S0 F30000 ; Fan 0 (Part Cooler) using Heater E1 Mosfet; Custom settings are not configured

    ; BLTouch code
    M557 X30:220 Y30:220 S45
    G29 S
    M307 H3 A-1 C-1 D-1
    M558 P9 H5 F100 T2000
    G31 X30 Y15 Z3 P25
    ;G31 P500 Z0.9
    G31 P500 Z1.11
    M375 ; load "heightMape.csv"

    ; homeall.g
    ; called to home all axes
    ;
    ; generated by RepRapFirmware Configuration Tool v2 on Fri Feb 01 2019 16:04:24 GMT-0500 (Eastern Standard Time)
    G91 ; relative positioning
    G1 Z5 F6000 S2 ; lift Z relative to current position
    G1 S1 X-305 Y-275 F1800 ; move quickly to X or Y endstop and stop there (first pass)
    G1 S1 X-305 ; home X axis
    G1 S1 Y-275 ; home Y axis
    G1 X5 Y5 F6000 ; go back a few mm
    G1 S1 X-305 F360 ; move slowly to X axis endstop once more (second pass)
    G1 S1 Y-275 ; then move slowly to Y axis endstop
    G90 ; absolute positioning
    G1 X15 Y15 F6000 ; go to first bed probe point and home Z
    G30 ; home Z by probing the bed

    ; Uncomment the following lines to lift Z after probing
    ;G91 ; relative positioning
    ;G1 S2 Z5 F100 ; lift Z relative to current position
    ;G90 ; absolute positioning

    ; homex.g
    ; called to home the X axis
    ;
    ; generated by RepRapFirmware Configuration Tool v2 on Fri Feb 01 2019 16:04:24 GMT-0500 (Eastern Standard Time)
    G91 ; relative positioning
    G1 Z5 F6000 S2 ; lift Z relative to current position
    G1 S1 X-305 F1800 ; move quickly to X axis endstop and stop there (first pass)
    G1 X5 F6000 ; go back a few mm
    G1 S1 X-305 F360 ; move slowly to X axis endstop once more (second pass)
    G1 Z-5 F6000 S2 ; lower Z again
    G90 ; absolute positioning

    ; homey.g
    ; called to home the Y axis
    ;
    ; generated by RepRapFirmware Configuration Tool v2 on Fri Feb 01 2019 16:04:24 GMT-0500 (Eastern Standard Time)
    G91 ; relative positioning
    G1 Z5 F6000 S2 ; lift Z relative to current position
    G1 S1 Y-275 F1800 ; move quickly to Y axis endstop and stop there (first pass)
    G1 Y5 F6000 ; go back a few mm
    G1 S1 Y-275 F360 ; move slowly to Y axis endstop once more (second pass)
    G1 Z-5 F6000 S2 ; lower Z again
    G90 ; absolute positioning

    ; homez.g
    ; called to home the Z axis
    ;
    ; generated by RepRapFirmware Configuration Tool v2 on Fri Feb 01 2019 16:04:24 GMT-0500 (Eastern Standard Time)
    G91 ; relative positioning
    G1 Z5 F6000 S2 ; lift Z relative to current position
    G1 S1 Z-300 ; seek end stop
    G1 Z5 ; back up
    G1 S1 Z-300 F300 ; home Z again slowly
    G90 ; absolute positioning
    G1 Z5 ; part nozzle 5mm above the bed



  • Call off the calvery....found the problem. I had the black and white connector kind of hidden in a wiring wrap and I stupidly did not check it closely enough. It was not making good contact. Sheesh.

    Thank you and sorry for the false alarm.


  • administrators

    @crchisholm said in Strange behavior from BLTouch:

    No, it doesn’t blink. Also, I don’t know if this has anything to do with the problem, but if I deploy with M 401, and then trip it with my finger, the pin retracts and then deployed again right away. (That may well be normal behavior, fhough)

    I think that's normal behaviour. M401 tells the firmware that you want the probe extended. For BLTouch there is no reason to use M401 or M402 except for testing the deploy and retract macros.


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