Unable to load filament, clicking noise after upgrade from MK3 to MK3S
 
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Unable to load filament, clicking noise after upgrade from MK3 to MK3S  

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vlada
(@vlada-3)
New Member
Unable to load filament, clicking noise after upgrade from MK3 to MK3S

Hi,
I've just upgrade the MK3 to MK3S and after upgrading firmware to 3.7.0 (mk3s version - this is what i should use right ?) I've went to wizard again. Everything was fine, until it tried to load the filament. It gets pulled in, but very soon the extruder gears start clicking and it stops from pulling more.

The filament ends up about 7.5 cm inside (from the visible top of the extruder). If I do unload, it unloads just fine and the tip does not seem melted in any way so I'm thinking for some reason it doesn't go all the way in. I opened up the side and folded up the second gear, and the filament is visible passing right through the middle of the gear and into the ptfe tube. With the side opened up, I am unable to lift it up, only unload helps.

What do you think I should try (please don't tell me disassemble everything and start from scratch 🙁 ).

Thank you,

Posted : 18/04/2019 1:56 am
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(@)
Illustrious Member
Re: Unable to load filament, clicking noise after upgrade from MK3 to MK3S

Did you unload filament before the upgrade work? Was it the same filament or could it have been PET or ABS with a higher melt point? Might be worth trying to preheat to ABS and then do a load. Just to rule out the simple.

Posted : 18/04/2019 10:34 am
vlada
(@vlada-3)
New Member
Topic starter answered:
Re: Unable to load filament, clicking noise after upgrade from MK3 to MK3S

Yeah, I did unload the filament 🙂 Couldn't have disassembled the hotend otherwise.
I've tried to load it after preheating to PETG, but nothing. While I don't think the hotend is jammed with molten fillament, something is really in there, which I don't know. Filament always gets in 7.5cm's from the top of the extruder and then it stops (this makes probably about past the PTFE tube - will measure)

Posted : 18/04/2019 12:09 pm
markus.i2
(@markus-i2)
Trusted Member
Re: Unable to load filament, clicking noise after upgrade from MK3 to MK3S

What I would try (in increasing order of desparation, went through a similar procedure in the last days -- in my case, one of the problems was that the screw holding the bondtech gear onto the motor shaft had become loose - still sticking enough to pull in the filament, but to loose to push it through the nozzle. After fixing that, I have a new problem occuring after a few hours when printing PLA, for which I haven't found a reason yet... ):

  • remove the extruder door, feeding tube and lock fitting on top of the extruder, then heat up the the nozzle, try to push filament through manually and try a cold pull
  • does the nozzle get hot? If not, you broke a heater or sensor wire.

  • can you push the filament through manually? If not, something is physically blocking the path

  • can you do a cold pull? any evidence for debris coming out?
  • If the path is mechanically blocked and you can't remove the blockage via cold pull, remove the nozzle and inspect it. Check visually for any obstruction in the nozzle and the heatbreak. If the path is clear, the issue probably is somewhere around the bondtech gears.

    Posted : 18/04/2019 10:02 pm
    vlada
    (@vlada-3)
    New Member
    Topic starter answered:
    Re: Unable to load filament, clicking noise after upgrade from MK3 to MK3S

    Thank you for the suggestions.
    I will start disassembling the extruder and check what you said. Another advice i received was that maybe the ptfe tube received is somehow jammed. Anyway, i still have to open up the extruder.

    As for damage to the heater, I doubt, because it's heating up to the chosen temperature and remains stable, and it "smells" hot. I didn't attempt to check it, but i remember the smell while i was trying loadings and unloadings.

    I'll return after the tests with the result / pictures. 🙂

    Thank you.

    Posted : 19/04/2019 6:05 pm
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    (@)
    Illustrious Member
    Re: Unable to load filament, clicking noise after upgrade from MK3 to MK3S

    Did you install the NEW MK3S PTFE that comes with the kit?

    Posted : 19/04/2019 6:54 pm
    vlada
    (@vlada-3)
    New Member
    Topic starter answered:
    Re: Unable to load filament, clicking noise after upgrade from MK3 to MK3S

    I have fixed it finally.

    1. I followed https://help.prusa3d.com/article/43mduc4zdn-filament-change-prompted-at-the-beginning-of-the-print to dissassemble and remove the hotend + heatblock + stuff (left hanging actually).
    2. I removed the ptfe tube and checked it (clean)
    3. I tried to push the filament in without the ptfe tube, it was still getting stuck at about the same length
    4. I heated it the hotend and using a needle tried to get in through the nozzle. It went up probably around the place where the jam was, but i wasn't sure and wanted it to go a little bit more.
    5. I removed the nozzle and then the heatsink (you have to do it while they are hot, otherwise it's a pain to unscrew them)
    6. The hotend is a e6 lite, which means there is a part which can't actually be removed.
    7. needle however now was going full length and i was confiend everything was clean
    8. when trying to assemble everything together, i found a very tiny little bit of black plastic on my desk. It's not melted and most likely it's part of the ring that holds the ptfe tube in place. Probably that part fell in the heatsink and was preventing the filament from advancing. Also, it was preventing the ptfe tube from going all the way in.
    9. After mounting the extruder back, the ptfe tube now, is lined up with the plastics where the gears are, while previously it was slightly above the plastic and actually touching the gears. ( https://d17kynu4zpq5hy.cloudfront.net/igi/prusa3d/lOY4CvMgSCGZSCv1.huge is how it should be)
    10. Preheat PLA -> Load filament and .... I've got a nice smooth line 🙂

    Happy that I found out and happy that I've learned some new things (although I would have preferred to learn them when i wanted and not when i had to).
    Thank you everyone that posted suggestions.

    Posted : 20/04/2019 6:10 pm
    markus.i2
    (@markus-i2)
    Trusted Member
    Re: Unable to load filament, clicking noise after upgrade from MK3 to MK3S

    Just to add to that - I also had a piece of filament clogging the heartbreak.

    Disassembling the extruder until I could get at the heatbreak went reasonably well, I also unscrewed the heat block from the heatbreak in the process. After disassemblimg the heatbreak to the bare metal, it was still clogged. Carefully heating up the hot end with a hot air gun and pushing the long 1.5 mm hex key through it from the other side finally got rid of the last part of filament.

    Now I just have to reassemble everything again 😕

    Posted : 22/04/2019 3:20 pm
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