Strange behavior from the z axis



  • Hi

    i dont know what a change but when i print my nozzle goes down instead goes up.
    every layer he goes 0.2 down.

    but in webcontrol it behave as i ask. ( + is up)

    i already try a different stl but the some problem.
    i change in S3D flip the axis but no difference

    somebody a idea?


  • administrators

    In your printer, does the nozzle move in the Z direction, or is the nozzle fixed and the bed moves up and down? If the bed moves instead of the nozzle, then +Z should move the bed down.



  • @dc42 said in Strange behavior from the z axis:

    In your printer, does the nozzle move in the Z direction, or is the nozzle fixed and the bed moves up and down? If the bed moves instead of the nozzle, then +Z should move the bed down.

    Although there is very scant information, he did say in his OP that it works correctly through DWC but wrong when he prints. Also he isn't reporting of homing issues so I'd guess that homing works too. In that case, I'd guess it's a slicer issue. He has indicated that he's using S3D but I have no knowledge of how that works.



  • Hi guys.

    I am talking about a tevo tarantula.

    So the nozzle is moving and not the bed.

    I dont think that's a slicer problem. Because yesterday the same stls from the SD have no problem. I changed only the webcontrol and firmware. And change some settings because of a other nozzle ( z offset Ans some other ) config.g is almost the same. (Z offset)

    The controls in webcontrol is good. So that's why i dont understand whats happening



  • @deckingman homing is indeed good.

    I also print with cura with same settings ass before.

    Very strange. But i dont know how i can move on



  • @mickey30m Does the Z axis move 0.2mm every layer or does it go to Z=0.2 and stay there? i.e. every time there is a layer change, does the nozzle get closer to the bed and eventually crash or does it stay 0.2mm above the bed? You haven't mentioned the nozzle crashing into the bed so I suspect it's the latter.

    In which case, it sounds like somewhere you have changed a setting so that the slicer is sending relative commands but the Duet is expecting absolute coordinates. Not sure why you keep mentioning stl files - it's gcode files that get printed. Take a look through the gcode file you are having trouble with. Use something like notepad++ and search for "G1 Z". Each time you encounter that the Z value should get progressively bigger. Does it do that?



  • @deckingman sorry. Its gcode offcourse. Its late for me. 🙂

    When hè print hè goes every layer closer to the bed. And hangs on something like 2.6.

    This is some code

    G1 Z0.198 F2202
    ; layer 1, Z = 0.198
    T0
    ; tool H0.220 W0.480
    ; skirt
    G1 X87.935 Y125.390 F9600
    G1 E0.0000 F4500
    G92 E0
    G1 X88.200 Y125.280 E0.0113 F2400
    G1 X111.800 Y125.280 E0.9438
    G1 X112.065 Y125.390 E0.9551
    G1 X114.610 Y127.935 E1.0974



  • @mickey30m This isn't making any sense to me. When you start to print, the nozzle should be at the first layer height above the bed. So in your gcode snippet, it should start at 0.198mm above the bed (G1 X 0.198). If it then changes 0.2mm closer to the bed, then the next layer would be with the nozzle touching the bed - lower than the first layer so causing the head to crash. Yet you say it gets closer to the bed each time "and hangs at something like 2.6".

    So something is very wrong. The only way it can get closer to the bed each time there is a layer change, is if it starts at some considerable distance above the bed which is clearly wrong. You say you changed the Z offset. That might account for it starting too high. In the gcode file, what is the next G1 Z command (after the G1 Z0.198 F2202)?

    It might be an idea if you post your config.g and homing files and also tell us what changes you made recently. You said "Z offset and some other stuff" so what exactly did you change?



  • @deckingman i Will post Them tommorow including a short video. And my settings.

    My first layer begins something like 2.1 because i have a z offset 1.9 but the exact thing that happend i Will post tommorow.

    As far i know i only change z offset. But i think that i make somewhere a misstake bacause this all happens so that's why i say i change z offset and something else.

    Many thanks for so far. I post tommorow.


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