Z lift on extruder changes - with Chimera

Discussion in 'Multi-Extrusion' started by triplanedave, Nov 24, 2015.

  1. triplanedave

    triplanedave Member

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    Have a Kossel Mini with RAMPS 1.4 and Marlin; printing via Repetier host. I have successfully printed 2-color prints, but at the time the color change occurs (switch from E0 to E1) the printer Z lifts up about 5mm.

    Here is the GCode at the time of the transition:

    G1 X13.581 Y11.119 E12.71375
    G1 X13.546 Y11.085 E12.71949
    G1 F1800.000 E7.71949
    G92 E0
    T1
    G92 E0
    G1 F1800.000 E-4.00000
    G92 E0
    G1 X-33.273 Y5.294 F7800.000
    G1 E4.00000 F1800.000
    G1 X-34.953 Y4.136 E4.24239 F540.000
    G1 X-35.626 Y3.807 E4.33135
    G1 X-36.822 Y3.450 E4.47958
    G1 X-37.373 Y3.390 E4.54540

    My guess is that it's a firmware setting that's forcing the hop - it happens slicing with either Slic3r or Cura. Here's a video of the print - up to and including the lift. [1drv.ms]

    Suggestions on what to check/change/etc to prevent this?
     
  2. UlrichKliegis

    UlrichKliegis Well-Known Member

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    You mentioned Marlin already. Do you have access to your installation / configuration file(s)? Marlin has tons of variables and switches that allow you to customize, optimize or cannibalize your controller and printer. There are a few parameters for Z-movement during empty moves and nozzle changes, among others. Also have an eye on the parameters that control E-retraction during moves. Then, there are some switches that let take Marlin control of these - or leave the functions to your host's output.

    Fun to analyze, and fun to modify. Even more fun to achieve an improvement.
    Risk of un-fun in the case of un-improvement...

    Take care!

    Cheers,
    U.
     
  3. triplanedave

    triplanedave Member

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    Yes, I do have access to the firmware code. It's required a significant amount of modification to get from a very finely tuned single extruder setup to a dual extruder. So, I'm pretty familiar with the files. But, do you have the settings/file for setting z-movement during empty moves? I don't recall running across those - either in configuration.h, or configuration_adv.h.
     
  4. triplanedave

    triplanedave Member

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    Did find this in configuration_adv.h


    // Default settings in "Auto-park Mode"
    #define TOOLCHANGE_PARK_ZLIFT 0.2 // the distance to raise Z axis when parking an extruder
    #define TOOLCHANGE_UNPARK_ZLIFT 1 // the distance to raise Z axis when unparking an extruder


    And, this one (seems more likely that the printer is lifting by 10mm than by 1mm, but I don't have ULTIPANEL enabled, so I have my doubts this is impacting things.:

    //adds support for experimental filament exchange support M600; requires display
    #ifdef ULTIPANEL
    #define FILAMENTCHANGEENABLE
    #ifdef FILAMENTCHANGEENABLE
    #define FILAMENTCHANGE_XPOS 3
    #define FILAMENTCHANGE_YPOS 3
    #define FILAMENTCHANGE_ZADD 10
    #define FILAMENTCHANGE_FIRSTRETRACT -2
    #define FILAMENTCHANGE_FINALRETRACT -100
    #endif
    #endif
     
  5. UlrichKliegis

    UlrichKliegis Well-Known Member

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    Hi Dave,
    glad to see you are within the innards already. I would have to look up the files myself, if I find some time these days. Unfortunately, there is a priority list that prevents this right now. But I am interested in your findings too, expecting my BigBox with dual extruders next month.

    Cheers,
    U.
     

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