Some Bltouch questions

  • Hello
    first i want to say sorry for my bad englisch i tried my best to understand the Wiki and to explain my problem here.

    I did Setup my BL Touch using the Wiki and all worked good thers is only one think i do not understand. If i start the G29 right after the G28 the sensor Crashes and Blink´s because the probe cant deploy complitly. Is this normal or just a mather of wrong installation from my side?

    Is it Posible to use the Bltouch for as a Homeing endstop? if so what do i need to do that thes deploying the probe if i hit G28?

    I also tried to get the G30 Bed Leveling running but i guess iam missing something important.
    Iam Using 2 Leadscrews with 2 Z motors on driver 2/3 middel left and middel Right from my 400*400 bed. Here is what i did setup:

    M584 X0 Y1 Z2:3 E4:5:6
    M671 X-15:380 Y250:250 S0.5 <- What do i need to set here i just dont understand it.

    G28 ; home
    M401 ; deploy Z probe
    G30 P0 X0 Y250 Z-99999 ; probe near a leadscrew
    G30 P1 X330 Y250 Z-99999 S2 ; probe near a leadscrew

    M402 ; retract probe

    Right now if i hit the G30 hes Deploying the probe and the Bltouch blinks again because of the deploying issue if i lift Z and hit G30 after that he´s just moving up until the Probe is triggert and then it stops.

    I really hope its somewhat
    understandable what iam trying to ask.

  • administrators

    Perhaps you need to raise the head a little before deploying the probe? To do that you can add something like this at the start of deployprobe.g:

    G91 ; relative movement
    G1 Z5 F1000 ; raise Z 5mm

  • Thanks that worked for the g29 but dose Not solve the Problem with the g30 or the Homeing with the bltouch.

  • administrators

    Which firmware version are you running? What do you have in your homez.g file and in the Z homing section of homeall.g?

  • 1.19
    Homez :
    ; homez.g
    ; called to home the Z axis
    ; generated by RepRapFirmware Configuration Tool on Tue Oct 10 2017 16:36:21 GMT+0200 (Mitteleuropäische Sommerzeit)

    ; Lift Z relatively to current position
    G1 Z5 F6000

    ; Move Z down until the switch triggers
    G1 Z-455 S1 F1800

    ; Back to absolute positioning

    ; Tell the firmware where we are
    G92 Z0

    ; Uncomment the following lines to lift Z after probing
    ;G1 Z5 F100


    ; Move Z down until the switch triggers
    G1 Z-455 F1800 S1

    What do i need to Change to use the Bltouch as Z endstop?

  • administrators

  • Thank you for that.
    Now i still have trouble with the G32 command.

    Iam leveling my axis like 0.5mm off and run G32 After G32 is over my axis are off like 1.4mm so what iam doing wrong?


    I tried it multible times in a row and its getting worse every time untill i get the Limit Error

    G28 XY ; home
    G28 Z
    G30 P1 X370 Y190 Z-99999 ; deploy Z probe
    G30 P0 X65 Y190 Z-99999 S2 ; probe near a leadscrew
    ; probe near a leadscrew

    M402 ; retract probe

    M584 X0 Y1 Z2:3 E4:5:6

    M671 X-15:380 Y240:240 S2 as the last command

  • administrators

    1. Swap the P1 and P0 on your G30 commands, because the P parameters should be in ascending order.

    2. Check that the Z motor driver numbers are specified in the same order as the M671 coordinates. To match your config.g file, the motor that drives the leadscrew at X=-15 should be the one connected to the Z motor output (driver 2) and the one at X=380 should be connected to the E0 motor output (driver 3).

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