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How do I do a easy filament change for multi color

Discussion in 'General Questions' started by David Avila, Sep 10, 2017.

  1. David Avila

    David Avila Member

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    How can I do a filament change in the middle of a print using octoprint or Matter control. Im looking for a easy way of doing it. Maybe when I pause on octoprint the extruder moves up and then when un pause goes back same spot. please help thanks for your time.
     
  2. OutsourcedGuru

    OutsourcedGuru Active Member

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    I have to verify this of course but Action Commands looks promising. (I've attempted to use Cura's PauseAtHeight post-processing script before and that failed miserably.)

    1. Search your GCODE file for the appropriate layer
    2. Insert an "M118 //action:pause" command on a line by itself
    3. If you want to be fancy, add an "M117 Change to blue filament" LCD message for yourself
    4. In OctoPrint, make sure that Actions Commands are installed as a plugin, noting that PAUSE is auto-defined
    5. Send that to print

    At Z=something, it should do the standard pause routine, as if you'd pressed the button on the LCD. (And we know that the LCD pause/resume is well-behaved, allowing you to do a Filament Change Wizard in between.)

    If this works, you could use the TweakAtZ OctoPrint plugin in combination to add that M118 command as above if you didn't want to edit the file manually.

    Hopefully this is in our version of the OctoPrint.
     
  3. David Avila

    David Avila Member

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    would this work?

    Screen Shot 2017-09-10 at 4.14.13 PM.png
     
  4. Geof

    Geof Volunteer Moderator
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    http://www.prusaprinters.org/color-print/

    I believe I put this in your R1 section post as well. Be clear, which machine do you have. Also apparently the Robo version of Cura for the C2/R2 causes issue with this utility tool and you'd have to downgrade to an earlier version to use it. Dont know what the deal is there as I dont have a C2 or a R2
     
  5. OutsourcedGuru

    OutsourcedGuru Active Member

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    @David Avila Not sure on the G91 version you have there. I have a thread on here where I attempted a variety of troubleshooting on this topic and I ran into trouble with the attempt which includes GCODE from that PauseAtZ plugin.

    If you're patient, let me verify this tonight and see if either approach works. My version hopes to invoke the native/trusted pause as if you pressed the LCD's pause button. (I like how the native version works because it saves its current position, raises the extruder and patiently waits with the extruder still at-temp. And then when you manually press the resume button, it gracefully returns and starts printing again at-temp.)

    To clarify, other methods just pause the job without moving the extruder up. This then results in an attempted return to the next layer start usually grinding the heated extruder tip through the top layers of your part, which isn't good.
     
  6. OutsourcedGuru

    OutsourcedGuru Active Member

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    This is the part where you pat yourself on the back for not being the guinea pig. I just ground my hotend into my print bed on this one.

    IMG_0299.jpg

    The attempt here was to print a small chess piece and to change the color after the base.

    Assumptions:
    * OctoPrint (RoboOS) : version 1.3.2
    * Cura : version 2.3.1

    1. In OctoPrint, added plugins Action Commands and M117 Popup and did the restart, confirming that they were installed
    2. In Cura, sliced rook with normal settings, basically
    3. Manually edited GCODE file, searching for layer 150 with the following edits:

    ;TIME_ELAPSED:1232.929313
    ; --------------------------------------
    ; Alert me (optional with sound upgrade)
    ; --------------------------------------
    OCTO805
    ; --------------------------------------
    ; Let ourselves know to change the color
    ; --------------------------------------
    M117 Change to white filament
    ; --------------------------------------
    ; Pause the print for a color change at Z = layer 150
    ; --------------------------------------
    M118 //action:pause
    ; --------------------------------------
    ;LAYER:150

    4. Send the job to print via the OctoPrint interface

    The job began printing normally, kicking in the standard PAUSE routine (or so I thought). I note that the assembly retired to the X=max, Y=MIN (back/right) corner and seemed to raise its height above the current Z level.

    I next ran the Filament Change Wizard, changing to white filament and getting to the end of that prompt sequence. I then returned to the Printer menu selection, noting that the RESUME/CANCEL buttons were still active. So far, so good.

    Pressing RESUME then dropped the assembly down to the Z=-something level (OUCH) and began grinding across the print bed. Good thing I didn't upload the video with my curses.

    So I'd call that a fail. Good thing that I have a replacement print bed waiting for me at Robo 3D to pick it up in a week or so.

    Note that this is a similar sort of fail as the previous attempt at using Cura's PauseAtZ. (At least that one didn't plunge below Z=0 for its stupidity; it just crashed into the top of my part.)

    Is there a good color-changing script? I don't know of one yet.
     
  7. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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  8. OutsourcedGuru

    OutsourcedGuru Active Member

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    @mark tomlinson I've got nothing to lose at this point. I'll give that a try.
     

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