HomeX - Endstop always triggered



  • Hi comm,

    I'm using optical endstops for X and Y in my CoreXY system.
    While Y is homing fine, I have a strange behaviour on X.
    When activating the Homex macro, the x axis moves about 1 cm to the right (although the endstop is on the left) and stops.
    M114 says x is 0.
    M119 says: X: at min stop (no matter if it's really at the endstop or not).
    When I move X into the endstop by hand, the LED on the endstop itself and on the Duet board triggers correctly (LED goes off, active high).
    So the hardware recognizes the endstop correctly, the firmware however tells me it's always triggered.

    This is my HomeX macro:

    ; homex.g
    ; called to home the X axis
    ;
    ; generated by RepRapFirmware Configuration Tool on Sat Nov 18 2017 16:35:09 GMT+0100
    
    ; Lift Z relative to current position
    G91
    G1 Z5 F6000
    G90
    
    ; Move quickly to X axis endstop and stop there (first pass)
    G1 X-305 F1800 S1
    
    ; Go back a few mm
    G91
    G1 X5 F6000
    G90
    
    ; Move slowly to X axis endstop once more (second pass)
    G1 X-305 F360 S1
    
    ; Lower Z again
    G91
    G1 Z-5 F6000
    G90
    

    Any ideas on this?
    If you need any further information, please let me know.
    Thanks in advance,
    Paul



  • I think your problem is that you are in absolute positioning mode when you tell it to move to x-305, which is not a valid absolute position, so it does nothing.

    So remove the G90 after you raise the Z axis, and again remove it after you go back to retrigger the endstop the second time.

    See my example below:

    G91               		; relative positioning
    G1 S1 X-375 F3000 		; move quickly to X axis endstop and stop there (first pass)
    G1 X5 F1000       		; go back a few mm
    G1 S1 X-10 F600  		; move slowly to X axis endstop once more (second pass)
    


  • This post is deleted!


  • @phaedrux
    Thanks for the answer.
    For HomeY, this works totally fine like I pasted the Macro in the initial post.
    Removing the G90's, like you suggested, has no effect unfortunately.
    I would expect the X axis going to the left (G1 X-305 in the HomeX macro), but it's going right for about 1 cm.



  • https://duet3d.dozuki.com/Wiki/ConfiguringRepRapFirmwareCoreXYPrinter#Section_Movement_section

    Go through this section and verify the directions of your A and B motors.



  • @phaedrux
    That's all working ok, I went through this page.
    On the "machine control" tab, when I press X-10, the axis moves to the left. So the direction in general is set up correctly



  • https://duet3d.dozuki.com/Wiki/Connecting_endstop_switches

    Double check you wiring for the X endstop.

    How do you have the endstops configured in config.g?



  • @phaedrux
    Just double checked, that seems fine.
    config.g endstop section:

    ; Endstops
    M574 Z0 S0 ; Set active low endstops
    M574 X1 Y2 S1 ; Set active high endstops
    M558 P1 X0 Y0 Z1 H5 F120 T6000 ; Set Z probe type to unmodulated, the axes for which it is used and the dive height + speeds
    G31 P600 X0 Y0 Z2.5 ; Set Z probe trigger value, offset and trigger height
    M557 X15:285 Y15:285 S20 ; Define mesh grid
    
    


  • @royce do you have a spare endstop to test with?



  • @phaedrux
    I think found the issue. I had a broken wire inside my wire hose.
    I will replace that one tomorrow (already late here) and report back


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