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PLA accumulating over and on the nozzle, flowing from above

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Posted (edited) · PLA accumulating over and on the nozzle, flowing from above



I am pretty new to 3DP and I am using an UMO+.


I am writing here because of the following issue. During a print, there is some melted PLA that accumulates on the top of the head, and slowly flow down onto the nozzle. This is no big deal for short prints (its easy to clean the mess when the head is at rest), but for longer prints this extra PLA eventually reaches the tip of the nozzle and badly interferes with the print.


See the attached annotated picture.


The first thing I thought was to lower the print temperature, but going as low as 184°C didn't solved my issue.

Another possibility is that there is some hardware issue: maybe an element of the head isn't screwed tightly enough?


What do you think?








Edited by antoninro
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    Posted · PLA accumulating over and on the nozzle, flowing from above

    Looks like a leaking nozzle, maybe not tightened enough? Or maybe there was some debris on the thread when it was tightened? I think they need to be tightened when warm, so any filament-remains on the thread would be molten. If fastened cold, it could leak. But I am not familiar with an UMO, so it is best if you google for a manual how to disassemble the UMO-nozzle.


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    Posted · PLA accumulating over and on the nozzle, flowing from above

    Agreed...It sounds like the nozzle needs to be tightened when heated, and was probably accidentally tightened when cold. 


    You can do an atomic/cold pull before changing the nozzle to make sure debris is not preventing the nozzle from tightening all the way.

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    • 2 weeks later...
    Posted · PLA accumulating over and on the nozzle, flowing from above

    Ok thanks I have cleaned the overflowing PLA and re-tighten the nozzle while hot, now there seems to be no leak anymore.

    See you around!

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