Gaps/under extrusion on inner walls and top surfaces.
Hello lovely people.
I come today with an issue that has appeared on my P1P prints a few days ago and I haven’t been able to solve.
As you can see from the pictures there seems to be an ongoing under-extrusion problem happening on inner walls and top surfaces, outer walls don’t seem to have any visible defect.
I print with PLA, always used mainly factory settings with 0 issues.
I also noticed that the first test line comes out with an uneven flow (see third picture).
What I have tried so far:
Checked for clogs: no PTFE tube, extruder, hot end clogs have been found (tried cold pull, used the little needle in the nozzle, used hex key method)
Changed the PTFE tube, changed the whole extruder unit, recently changed the nozzle;
Tried to calibrate the machine (both flow dynamics and rate);
Did a factory reset;
Tried to change flow rate and retraction settings as per some other threads suggestions, no visible difference noticed;
Used different filaments from different batches and brands to exclude wet filament issue;
Tried to add fuzzy skin on the inner walls to mask the defects but I can still see a visible difference of quality.
Tensioned the belts
Do you have any idea/suggestion of what I can try to do in order to fix the issue?
If I missed any important detail that would help troubleshooting please let me know and I will add them.
Thank you for your input! Yes, I have disassembled the whole hot end yesterday and re added a layer of thermal grease under the ceramic plate and thermistor.
If you heat up the nozzle and manually extrude filament (via the display) does the filament come out in a straight line down or does it curl and snake around?
It sounds to me like you’ve done most of the right troubleshooting steps already. I think @JonRaymond is on the right track in suggesting investigating your filament flow from the nozzle.
That said, you may not have a clog but it is possible that you have buildup. One test you can try out that costs almost nothing is to handfeed a contrasting color through your nozzle during a print test. If you see that you are getting multiple colors in your extrusion, that might be an indicator of excess buildup. The option there is to heat the print nozzle up really high, in excess of 275c and then manually feed filament through it. The goal here is to just verify that you’re getting 100% filament flow and that’s what the contrasting colors will do as a troubleshooting technique.
There is also the possibility of some binding in the filament path. It sounds like you checked for that already but try hand feeding filament independent of the PTFE tube and see if you get a different result. If you do, then again, that points to some sort of binding in the filament path which would explain this part of your image.
Yes, the filament comes in a straight line. I have also tried the manual hex key de-clogging method and use that mini needle…
@Olias thank you so much for your suggestion.
I have bought a cleaning filament roll which should come today, I am hoping to run that through and see if there is an internal build up as you are suggesting.
I’ve also run a max volumetric flow test with a result of 9mm3/s - a user on Reddit suggested that if the results were belo 25mm3/s then the problem would be a mechanical/hardware one, rather than a software/slicer one.
Following both of your advices I will try and swap the nozzle again and see if this sorts the issue.
I will report back, thanks again!
Hi! It ended up being the nozzle, as other people suggested. Despite doing everything suggested to clear a potential clog (cold pull, heating the hex key, clearing the extruder), there was likely a build up inside the nozzle. I didn’t think it could be that as it was less than a month old, and I have been printing with the same filaments for over a year.
It also didn’t help that while trying to extrude some filament to check for a clog the flow was constant and in a straight line.
I would suggest to try and run some cleaning filament through it, or if you have a spare one try and see if it does the trick.
All the best!
