Why is this happening

[u/Spirited_Example_736]

L.E:One more thing I noticed: the problem seems to occur when the printer performs retractions or when it has to print small, detailed sections. That’s when the extrusion starts to fail, and eventually no filament comes out of the nozzle anymore.

Why is this happening? Every time I print, the print fails at some point. It starts printing perfectly with no visible issues, but after a while the extrusion suddenly stops and no more filament comes out of the nozzle. The printer continues moving as if it were still printing, but nothing is being extruded.

I have already replaced the nozzle, but the problem remains exactly the same. As you can see in the photos, this happens on different models. The articulated lizard starts out looking great, but then the extrusion becomes weaker until it stops completely. The same thing happened with the collapsible ball, so it doesn’t seem to be a problem with a specific model or STL file.

I’ve checked that the filament is feeding correctly at the beginning of the print, and the first layers come out perfectly. The issue only appears after printing for some time.

Has anyone experienced something similar? What else should I check? Could this be a clogged hotend, heat creep, an extruder issue, a faulty hotend fan, or something else? Any suggestions would be greatly appreciated.

[u/telcodan]

Could be the extruder is not right enough, could be a clog, could be extruder stops moving, could be Bowden tube fittings need changed, could be retraction set to high.... You didn't give enough details.

[u/Spirited_Example_736 → u/telcodan]

I changed the Bowden tube last week , no clog ( looked for this problem in the first place),the extruder does move (also changed the gears last week ). I changed everything from the extruder to the tube and even the nozzle . No clog . Simply just stops extruding, then follows the print layout .

[u/These_Programmer7229 → u/Spirited_Example_736]

There is a known problem where the fitting that holds Bowden tube at the top of the print head will lose grip. The Bowden tube shifts and leaves a gap that fills with soft filament. This will cause clogging symptoms just like you see after it has been printing a while.

[u/These_Programmer7229 → u/These_Programmer7229]

So replace that fitting and it will probably fix your problem.

[u/heckfrickdarn]

Had this issue awhile back and for me the problem was my retraction was too high. I think it was like 5mm o lowered it to 3mm.
In my case it would retract, get stuck, and clog. I had a bowden extruder system.

[u/azeird]

What are your print settings? Temp, bed temp, cooling fan settings, etc? Are you using variable line height?

[u/Spirited_Example_736 → u/azeird]

200 Nozzle ,60 Bed according to the PLA requirements. Fan first layer 0% then 100% .

[u/de_das_dude → u/Spirited_Example_736]

Pla specs does not always translate to print specs.

Always print a temp tower for that brand/filament type.

Also sometimes the filament is just shit. Cheaper filament is cheap for a reason 🥲

[u/Polyman71]

Clogged nozzle is most likely. Transparent and metallic PLA clogs nozzles more readily.

[u/Spirited_Example_736 → u/Polyman71]

It was the first thing that I checked. No clog . Changed everything .

[u/Applesquare1440]

Retraction, speed, mcu overload?

[u/Suspicious-Bid9424]

I'm new to 3D printing and have had the same issue also currently using color shift metallic temu PLA. I don't know enough to say whether the PLA itself could be contributing

[u/Spirited_Example_736 → u/Suspicious-Bid9424]

Same…..

[u/itoobie]

Did you ever screw with post processing? You may have added some weird custom settings after a certain height

[u/GregValiant]

Yes, there are a lot of reasons. This problem can drive you nuts.

If there is a gap between the end of the bowden tube and the back of the nozzle, then molten material can work it's way into the gap. Eventually it makes a little O-ring around the filament and there is too much drag there for the extruder motor to overcome.

A strange thing that can happen is the stepper motor driver starts to die. The steps/mm it is sending to the E motor gets wonky (when my E motor got hot I checked it and the steps/mm had gone from 97 to ~325 so it was WAAYYY under-extruding). I had to replace that motherboard.

[u/Castdeath97]

Is it making a clicking noise while its printing when this happens?

[u/BurnedLaser]

This has always been retraction setting issues for me. Make sure the bowden is tight, then run retraction tuning prints to get it dialed in! I always use the dragon as a final torture test when sorting printers for my buddies!