<p>I always used electric guitar strings. They are 0.05 mm smaller than the nozzle and because of the texture it scratches off any material that is stuck. Plus since it's not hard there's is almost no chance to damage the nozzle</p>

CC BY-SA 4.0
2021-11-21T21:55:57.810Z
2021-11-21T23:58:34.760Z
2021-11-21T23:58:34.760Z
The Developking
<p>My Prusa i3 MK3S printer experienced a partial clog last time I was printing with nylon.</p>
<p>Although I've experienced clogs and partial clogs before, all the usual tricks I've tried have not worked this time; using an acupuncture needle to dislodge the blockage, running cleaning floss filament through at 285 °C, as well as numerous hot and cold pulls.</p>
<p>Despite all of the above, and being able to run some filament through the nozzle manually, as soon as I start to try and print, there is too much resistance for the extruder to force the filament through the nozzle and the Bondtech gears just grind up the filament instead of extruding it.</p>
<p>I've also removed the PTFE tube and checked that and it's in perfect condition.</p>
<p>Is there anything else I can try to try and clear the blockage? I'm highly reluctant to change the nozzle, as last time I did this, I bent the heatbreak despite following Prusa's instructions to the letter - the nozzle was just too seized in the heat block, I assume with degraded/encrusted filament.</p>

<prusa-i3><troubleshooting><extrusion><underextrusion><maintenance>
Clearing persistent partial clog after printing nylon
Andrew Ebling
# Clearing persistent partial clog after printing nylon

(Asked by: username_0 on 2021-11-21)

My Prusa i3 MK3S printer experienced a partial clog last time I was printing with nylon.

Although I've experienced clogs and partial clogs before, all the usual tricks I've tried have not worked this time; using an acupuncture needle to dislodge the blockage, running cleaning floss filament through at 285 °C, as well as numerous hot and cold pulls.

Despite all of the above, and being able to run some filament through the nozzle manually, as soon as I start to try and print, there is too much resistance for the extruder to force the filament through the nozzle and the Bondtech gears just grind up the filament instead of extruding it.

I've also removed the PTFE tube and checked that and it's in perfect condition.

Is there anything else I can try to try and clear the blockage? I'm highly reluctant to change the nozzle, as last time I did this, I bent the heatbreak despite following Prusa's instructions to the letter - the nozzle was just too seized in the heat block, I assume with degraded/encrusted filament.

**Tags:** prusa-i3, troubleshooting, extrusion, underextrusion, maintenance


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## 1 answers

### Answer by username_1 on 2021-11-21. Score: 1

I always used electric guitar strings. They are 0.05 mm smaller than the nozzle and because of the texture it scratches off any material that is stuck. Plus since it's not hard there's is almost no chance to damage the nozzle


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