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filament stuck to print-head (brand-dependent jam?)
 
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filament stuck to print-head (brand-dependent jam?)  

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rhjpires
 rhjpires
(@rhjpires)
Active Member
filament stuck to print-head (brand-dependent jam?)

Hello everyone,

Wondering if anyone ca give me a hand in troubleshooting a problem with my i3 mk3.

TL;DR: I've got a PLA filament that from the first moment I used it showed signs of printing problems, and finally culminated with the filament being stuck to the print-head and now cannot be dislodged.

The long version:
This is my first 3D printer which I've used for a couple of months with no issue until I decided recently to try a new filament (Janbex PLA White).
I've printed with Prusa's PLA before with no problem, and I've printed with several brands of PETG also with no issue.

  • I started a new print with Janbex PLA using the PRUSA PLA settings in Slic3r. The printing started apparently well, but several hours later when I came to check the printing there was no extrusion happening although the printer continue to move the head around as if it was extruding. The printing had failed shortly after the initial 1 or 2 layers.

  • I attempted to play with the temperature, increasing it from 210-215 °C up to 230°C to see if that would help on the extrusion, but it did not.

  • I removed the Janbex PLA and loaded it again, but again I could not detect any extrusion - at this point I begun to be a bit worried.

  • I then removed the Janbex PLA, and loaded the Prusa PLA and voilá, there was extrusion - I felt relieved.

  • Removed the Prusa PLA and loaded Janbex PLA again, and started the print job with the same g-code as before. Shortly after I could see that the printing was not going well, some of the parts being printed showed significant defects and in order to avoid total and utter failure i decided to cancel the print.

  • I then decided to remove the Janbex PLA but to my surprise it is, since then, stuck to the print-head, I cannot remove it. The filament is always loaded according to the printer which only gives me the possibility to unload the filament, but upon selection of this option the filament cannot be removed.

    • One thing I could notice is that the PLA from Janbex feels very different from the PLA from Prusa - the latter feeling more rough to the touch. I wonder at this point how much a particular filament from particular brand can create problems, or if this is all just an unlucky coincidence of factors.

    If anyone has any comments, suggestions or advice on how to proceed please drop me a note.

    Best,
    Ricardo

    Veröffentlicht : 19/09/2018 8:45 am
    bobstro
     bobstro
    (@bobstro)
    Illustrious Member
    Re: filament stuck to print-head (brand-dependent jam?)

    If the filament is just stuck inside the hotend, warm up to print temperature, extrude some filament using the front panel (Settings->Move->Extruder) then try ejecting again. If this doesn't work, describe in more detail what is going on. Is the filament coming partway out? Can you open the extruder door and see if it's stuck inside?

    My notes and disclaimers on 3D printing

    and miscellaneous other tech projects
    He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

    Veröffentlicht : 19/09/2018 10:28 am
    rhjpires
     rhjpires
    (@rhjpires)
    Active Member
    Themenstarter answered:
    Re: filament stuck to print-head (brand-dependent jam?)

    Hi Bobstro,

    thanks for the reply!
    I did as you suggested, but it did not work.
    Using the move extruder command i turned the knob, initially up to 9, and on a second attempt up to 54 - no extrusion on either case.
    The printer automatically went to a unload filament mode, asking me to pull out the filament but again it did not work.

    In the meantime, I had opened the idler door to inspect filament and pulleys (images attached) and it seems there is by now considerable grinding of the filament (notice filament dust ),

    Unfortunately, after I inspected the pulleys, in my last attempt to pull out the filament (using pliers) the filament broke - I have now no external access to the filament.

    Please let me know some suggestions.

    Could this be related with poor grip from the very beginning?

    Veröffentlicht : 19/09/2018 11:16 am
    Phil
     Phil
    (@phil-4)
    Trusted Member
    Re: filament stuck to print-head (brand-dependent jam?)

    I've had this happen twice now with odd filaments. If the filament jam is completely in the extruder and you have no way to get at it, there are still a couple things to try:

    1) Heat the nozzle to about 270, wait for 10 minutes and then try to load a new filament in. This may push the filament out, but be careful you don't make it worse. Stop immediately if it isn't working.
    2) Remove the nozzle and try to clean it out with the accupunture needle you originally got.
    3) Follow these steps: https://help.prusa3d.com/l/en/article/WWVRzOY1dX-clogged-nozzle

    I have had to do #3 (wire through extruder) twice. Its a bit scary, but it worked. If you live in the US, use a 16 gauge SOLID (not stranded) wire that you strip back about 6 inches. 14 gauge will work, but be careful as its technically slightly too big.

    Veröffentlicht : 19/09/2018 5:04 pm
    rhjpires
     rhjpires
    (@rhjpires)
    Active Member
    Themenstarter answered:
    Re: filament stuck to print-head (brand-dependent jam?)

    Hello everyone,

    many thanks to Bobstro and Phil.S6 - your input helped me to solve the problem.
    The issue I was experiencing was likely a combination of clogging with lack of grip with Janbex White filament.

    As I had the filament clipped inside the extruder head (no filament hanging outside), I noticed that the pulleys would rotate but not move the filament neither up nor down. The existence of a significant amount of dust near the pulleys suggested filament degradation which would imply reduced grip performance.

    Hence, what I did was to tighten the idler door screws a bit more, in order to bring the pulleys teeth more in contact with the filament. Then, to help evacuate the stuck piece of Janbex White filament out of the extruder, I also fed a new filament (Prusa PLA silver). Upon heating the nozzle up to 215°C, extrusion of the stuck filament occurred - so, problem solved!!

    Many thanks to everyone.

    Best,
    Ricardo

    Veröffentlicht : 20/09/2018 8:26 am
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