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Reoccurring Partial Nozzle Clogs  

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Gronis
(@gronis)
Active Member
Reoccurring Partial Nozzle Clogs

Hi there Prusa and every prusa user reading this.

I've been been using my MK3 almost non-stop since I got it. I really enjoy using it. But I have some printing quality issues recently related to partial nozzle clog/under extruding.

The problem:
My printer starts under extruding every now and then since 2 months back. I've been using the acupuncture needle which resolves the issue for maybe 2-3h of printing time. I've tried to do cold pulls at least 3-4 cold pulls at 4 different times, but the problems is still coming back after a few prints.

2 weeks ago, I just replaced the nozzle because I didn't stand the trouble of repeatedly having to worry and fix the partial clogs.

And it has been working wonderfully for 2 weeks, until today, after 1kg of PLA since the nozzle replacement, I realised my night print has fallen for the same under extrusion problem due to a partial clog.

How can I resolve this? Do I need to tear appart the whole extruder to find the issue? I have also ordered the MK3S upgrade so maybe I can try to fix the issue at the same time, while switching out the extruder parts to the new MK3S design.

Pictures of the problem:

Posted : 09/03/2019 10:45 am
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(@)
Illustrious Member
Re: Reoccurring Partial Nozzle Clogs

When you changed the nozzle, did you clean out the filament channel from the nozzle upwards? Debris from printing and jams can fall down from the gears and collects in gaps in the PTFE and heat break where they jostle and eventually pack and jam. If you've seen any dust collecting around the Bontech gears, clean the heatbreak out.

Remove the nozzle, open the idler door - and blast canned air up through the filament path. If you see a cloud of dust, you know this may have been the problem. Finish by cleaning out the gear bay and filament sensor window and a blast down the PTFE.

Posted : 09/03/2019 6:50 pm
Gronis
(@gronis)
Active Member
Topic starter answered:
Re: Reoccurring Partial Nozzle Clogs

Thanks for the answer!

When you changed the nozzle, did you clean out the filament channel from the nozzle upwards?

No, I did not.

Remove the nozzle, open the idler door - and blast canned air up through the filament path. If you see a cloud of dust, you know this may have been the problem. Finish by cleaning out the gear bay and filament sensor window and a blast down the PTFE.

I will try this and see if it helps.

Posted : 10/03/2019 12:10 pm
Gronis
(@gronis)
Active Member
Topic starter answered:
Re: Reoccurring Partial Nozzle Clogs

After performing this procedure, I believe it was causing this issue with high probability. I popped 3 dust clouds out of the feeder with compressed air, 2 upwards and one from the top.

The filament seams to flow much better now. Before it felt that the filament output lagged behind the feeder gears. Now the feeder and the filament output are much more in sync.

I report back in a few weeks if the problem does not occur again, or as soon as the problem reappears if it comes back.

Posted : 10/03/2019 2:56 pm
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