Hot End stopping on and melting into print at end of print



  • I have searched and read and read and searched but my issue persists. Any help would be greatly appreciated.

    At the end of any print the hot end just stops at the last point that it printed and slowly melts into the print. After what seems like a couple of minutes it eventually homes leaving a molten mess where it sat.

    I am printing with a Anycubic Kossel Linear Plus with the stock hot end.

    My end G-code in Cura looks as follows (I added M83 based on recommendations to what I thought was a similar issue s I am experiencing):

    ;End GCode
    M104 S0 ;extruder heater off
    M140 S0 ;heated bed heater off (if you have it)
    G91 ;relative positioning
    M83
    G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure
    G1 Z+10 E-5 X-20 Y-20 F{travel_speed} ;move Z up a bit and retract filament even more
    G28 ;move to endstop
    M84 ;steppers off
    G90 ;absolute positioning

    I also updated to the latest firmware today (wifi and web control also) but it made no difference.

    Please forgive me if I missed the solution or am not seeing something obvious. I am not very well versed in G-code yet.


  • administrators

    @bobskinner

    try putting these two lines:

    G91 ;relative positioning
    M83
    G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure
    G1 Z+10 E-5 X-20 Y-20 F{travel_speed} ;move Z up a bit and retract filament even more

    before you turn your heater off.



  • @bobskinner

    In your actual gcode file does F{travel_speed} get translated into an actual feed rate?

    You could try splitting that combined z e and x y move into seperate steps since that move would be limited by the slowest axis.

    M83 is correct. You only want to retract 1mm of filament not move to the first mm you extruded. Do you have Cura set to use relative extruder moves? I believe the setting is in the experimental tab.



  • @t3p3tony said in Hot End stopping on and melting into print at end of print:

    @bobskinner

    try putting these two lines:

    G91 ;relative positioning
    M83
    G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure
    G1 Z+10 E-5 X-20 Y-20 F{travel_speed} ;move Z up a bit and retract filament even more

    before you turn your heater off.

    I turn my heaters off first. Everything should still be at temp so it shouldn't be a cold extruder issue?

    '''
    ; stop.g
    ; called when M0 (Stop) is run (e.g. when a print from SD card is cancelled)
    ; Also called by slicer end gcode by M0
    ;
    M400 ; Finish move queue
    M104 S0 ; Extruder heater off
    M140 S0 ; Bed heater off
    M106 S255 ; Fan at 100 to cool nozzle and bed
    G91 ; Relative positioning
    M220 S100 ; Set speed factor back to 100% in case it was changed
    M221 S100 ; Set extrusion factor back to 100% in case it was changed
    G1 E-2 F9000 ; Retract filament 2mm
    G1 X5 Y5 F9000 ; Wipe nozzle
    G1 Z20 F500 ; raise nozzle 5mm from printed part
    G90 ; absolute positioning
    G1 X150 Y130 F6000 ; Move x and Y axis over to bed center so probe is on top of bed
    ;M104 S35 ; Set hot end low and wait
    G4 S60 ; Wait 5 minutes
    ;M116 ; wait for temp to drop
    G28 X Y ; Home X and Y
    G28 X Y ; Home it again, Sam.
    M290 R0 S0 ; clear babystepping
    M84 ; Steppers off
    M98 P"ZSpeedsNormal.g" ; Load normal z speed settings again.
    M106 S0 ; Fan off

    ;Play a little beep beep beep to show print ended.
    M400 ; Clear queue again before jingle
    G4 S1
    M300 P250 S750
    G4 P251
    M300 P200 S1250
    G4 P201
    M300 P250 S750
    G4 P251
    M300 P200 S1250
    G4 P201
    M300 P250 S2500
    G4 P251
    M300 P150 S2000
    G4 P151
    M300 P150 S2500
    G4 P151
    M300 P350 S3700
    G4 P351


  • administrators

    @Phaedrux actually yes, you are right



  • Thank you for the replies!

    I am in the middle of a print right now (at the end of which I have to pay attention to manually force the nozzle away from the print to prevent my previously mentioned issue) I will try the suggestions after that.

    This potentially undefined variable in the following line confuses me:
    G1 Z+10 E-5 X-20 Y-20 F{travel_speed}

    Where would "travel_speed" be defined? All I know is that I used this same end G-code when I still had the original tri-gorilla board in the delta and it behaved as expected. Methinks this might be playing a role in my problem, maybe, possibly, I don't know...

    All this G-code is making my head spin and I know it isn't even super technical yet...

    I do have relative extrusion checked in Cura.



  • @bobskinner Here's my end gcode for prusa slicer:
    M104 S0 ; turn off temperature
    M140 S0 ; turn off bed
    G1 X0 ; move x to left
    G1 Y240 ; move bed to front
    M84 ; disable motors



  • @bobskinner said in Hot End stopping on and melting into print at end of print:

    Where would "travel_speed" be defined?

    I believe that would be a Cura token. You'd have to check the actual exported gcode file to see if it's being evaluated to an actual number. In theory it should be the travel speed defined in the Speed tab of the settings.



  • I checked the output G-code file and it still has F{travel_speed} in it... I changed it to F500 and now everything works just dandy!

    Thank you so much for the help!



  • @bobskinner according to this page: http://files.fieldofview.com/cura/Replacement_Patterns.html
    it should be "{speed_travel}" , not "{travel_speed}"


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