BLTouch probe malfunction and Z stepper warning



  • I have an Anet A8 with a BLTouch probe and E3D hotend that I've been trying to set up with a Duet 2 Wifi board.

    I was able to get the board to recognize the Z probe, however when I tried to home the Z axis, it never deployed the pin on my BLTouch probe, and instead just rammed the unit into my print bed. The probe will respond to gcode commands such as M280 P0 S120.

    Also, I get the following message when I try to move the Z axis by more than 0.5mm: “Warning: motor phase B may be disconnected reported by driver(s) 2”

    Any ideas what might be causing this? I have already read through https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe several times, it isn't helping. I've attached my config.g file: config.g


  • Moderator

    What do you have in deployprobe.g?



  • @Phaedrux M280 P0 S10


  • Moderator

    Unfortunately I can't view your config on my phone but I assume you're using rrf3?



  • @Phaedrux yes:

    Firmware Name: RepRapFirmware for Duet 2 WiFi/Ethernet
    Firmware Electronics: Duet WiFi 1.02 or later
    Firmware Version: 3.0 (2020-01-03b3)
    WiFi Server Version: 1.23
    Web Interface Version: 1.22.6


  • Moderator

    Could you copy and paste the bltouch section of the config?

    Also you should be using dwc 2.0.7 with rrf3


  • Moderator

    Also for the z axis error check your wiring. The error may be telling you exactly what's wrong.



  • @Phaedrux
    M574 Z1 S1 P"!zstop" ; configure active-low endstop for low end on Z via pin zstop

    ; Z-Probe
    M558 P9 C"^zprobe.in" H5 F100 T2000 ; Set Z Probe to type BLTouch
    M950 S0 C"exp.heater3"
    G31 X0 Y0 Z3.3 P25 ; Set Z probe trigger value, offset and trigger height
    M557 X20:200 Y20:200 S40 ; define mesh grid



  • I think you should use Z0 in M574 command. Look at : https://duet3d.dozuki.com/Wiki/Gcode#Section_M574_RepRapFirmware_Num_3


  • administrators

    The first thing is to check whether the M401 and M402 commands deploy and retract the pin. Do they?



  • @aidar thanks, I've changed it, but that doesn't appear to have done anything



  • @dc42 M401 and M402 commands work as expected.


  • Moderator

    Please post your homing files.



  • @Phaedrux That Z axis error regarding the motor phase was indeed a faulty connection, it's been repaired. Thank you.

    The home files are below. FYI, I have not altered these; when I do a home all, it pushes the bed all the way back in the Y axis to home it, which leaves the bed well behind the Z axis probe. So after homing X and Y, it moves the Z down, but the bed is no longer under the Z probe. I suppose I'll need to add something to move the bed forward again after the Y axis is homed; my bigger problem is that the pin on the Z probe doesn't extend.

    homeall.g
    homex.g
    homey.g
    homez.g


  • Moderator

    The reason the pin isn't extending is because your homeall.g and homez.g are configured to use an endstop switch and not the probe.

    ; homeall.g
    ; called to home all axes
    ;
    ; generated by RepRapFirmware Configuration Tool v2.1.5 on Thu Jan 09 2020 15:52:13 GMT-0500 (Eastern Standard Time)
    G91                     ; relative positioning
    G1 H2 Z5 F6000          ; lift Z relative to current position
    G1 H1 X-258 Y-235 F1800 ; move quickly to X and Y axis endstops and stop there (first pass)
    G1 H2 X5 Y5 F6000       ; go back a few mm
    G1 H1 X-258 Y-235 F360  ; move slowly to X and Y axis endstops once more (second pass)
    G1 H1 Z-245 F360        ; move Z down stopping at the endstop
    G90                     ; absolute positioning
    G92 Z0                  ; set Z position to axis minimum (you may want to adjust this)
    

    It should be

    ; homeall.g
    G91                     ; relative positioning
    G1 H2 Z5 F6000          ; lift Z relative to current position
    G1 H1 X-258 Y-235 F1800 ; move quickly to X and Y axis endstops and stop there (first pass)
    G1 H2 X5 Y5 F6000       ; go back a few mm
    G1 H1 X-258 Y-235 F360  ; move slowly to X and Y axis endstops once more (second pass)
    G90                     ; absolute positioning
    G1 X150 Y150 F6000 ; move the probe to the center of the bed. Adjust as needed.
    G30 ; probe the bed
    G1 X5 Y5 Z5 F6000 ; return to a parked position
    

    For homez you have

    ; homez.g
    ; called to home the Z axis
    ;
    ; generated by RepRapFirmware Configuration Tool v2.1.5 on Thu Jan 09 2020 15:52:13 GMT-0500 (Eastern Standard Time)
    G91               ; relative positioning
    G1 H2 Z5 F6000    ; lift Z relative to current position
    G1 H1 Z-245 F1800 ; move Z down until the endstop is triggered
    G92 Z0            ; set Z position to axis minimum (you may want to adjust this)
    

    But you should have

    ; homez.g
    G91               ; relative positioning
    G1 H2 Z5 F6000    ; lift Z relative to current position
    G90                     ; absolute positioning
    G1 X150 Y150 F6000 ; move the probe to the center of the bed. Adjust as needed.
    G30 ; probe the bed
    G1 X5 Y5 Z5 F6000 ; return to a parked position
    

    Notice that it now positions the probe at the center of the bed and then sends G30 to actually use the probe. Then returns to a position off to the side. You'll have to modify the probing position and the parking position to suit your needs.



  • @Phaedrux Thank you, that got it working!


Log in to reply