Notifications
Clear all

[Solved] PETG breaking walls and unregular patterns  

  RSS
dbv
 dbv
(@dbv)
Active Member
PETG breaking walls and unregular patterns

Hi,

I recently got some issues with an error pattern, that I am unable to match to a cause (yet). Maybe somebody else has seen this?

The pictures below show two different models with two different types of PETG filament from different vendors.

Here is what I see:

  • The surface on outer walls gets uneven, develops occasional spots and cracks easily.
  • The first couple of layers of a print usually are acceptable, but with increasing height, the problem appears, but doesn't seem to get worse as higher it gets.
  • There are occasional breaks in the pattern on bigger prints which then return to the normal quality, before decaying again.
  • Especially the model 02.07 has been printed with the same print settings before without problems.
  • Other models seem to print fine (with different filaments), but these do not include straight walls or are of significant height.
  • I was guessing the belt tension might have caused this, but the problem is persisting after re-tensioning.

I take suggestions of what to look into.

 

thx, d.

Best Answer by Neophyl:

Thats not belt tension, it looks purely like an extrusion issue.  So look at partial clog, feed gears- tension, ptfe tubes, confirm the extruder thermistor is reading accurately etc.  Basically anything that can cause problems with extrusion.

Posted : 12/07/2025 10:56 am
Neophyl
(@neophyl)
Illustrious Member
RE: PETG breaking walls and unregular patterns

Thats not belt tension, it looks purely like an extrusion issue.  So look at partial clog, feed gears- tension, ptfe tubes, confirm the extruder thermistor is reading accurately etc.  Basically anything that can cause problems with extrusion.

Posted : 12/07/2025 12:30 pm
dbv
 dbv
(@dbv)
Active Member
Topic starter answered:
RE: PETG breaking walls and unregular patterns
Posted by: @neophyl

Thats not belt tension, it looks purely like an extrusion issue.  So look at partial clog, feed gears- tension, ptfe tubes, confirm the extruder thermistor is reading accurately etc.  Basically anything that can cause problems with extrusion.

Thanks. Especially the feed gears tension I'll have a look into. I had to clean the filament sensor on the printer (mk4s) and needed to remove the gear cover for that lately. I'll let you know.

Posted : 12/07/2025 2:50 pm
dbv
 dbv
(@dbv)
Active Member
Topic starter answered:
RE: PETG breaking walls and unregular patterns (solved)

So, after a while (and some hedge/garden work that came in the way): Replacing the nozzle with a clean one worked. I didn't have the tool handy to clean the current nozzle, so I put in the obsidian-one I had laying around. Immediate improvement.
I also noticed some slight wear-and-tear on the the silicon-cover over the print head. (#cough) and replaced that one as well.

Thanks for diagnosing this.

Posted : 23/07/2025 11:33 am
Share: