Hello dear community,
I am using A1 mini, latest firmware, latest bambu studio, stock settings/profiles.
I have several rolls of PETG-HF filament.
While white PETG-HF is fine, it prints OK for me,
black roll (from same order) is having issues/bubbles on prints.
On the same gcode, no other changes except different roll of filament.
I dried black roll for 10 hours on 62 deg in Sunlu S2 dryer (with a bit of lid open to humid air go out) - still no improvements. Still I got same results.
I tried to modify printing temperature, flow rate, etc - no, same issue on black.
What could be the problem? Dry more? Is something wrong with roll itself?
Got almost the same experience with one roll of petg hf that i got last month. Usually it prints pretty good but that one roll was really bad. Even after drying it several times it wouldn’t print as it should.
I thought about try and sending it back but in the end i forgot about it and used it as support interface until the end.
Maybe a bad batch because even after drying it wouldn’t print good. That happens
I dried tonight for 6h on 65C on Sunlu S2 with 2cm opened lid for moist air to go away.
At the end 19% RH.
Re-printed - again same issue.
Well, I can of course dry even more… but I am not sure if this is going to be any better.
Do you think this is wet filament issue? I can dry last time for 10h on 65C… but I doubt it would help…
Could it be something else with this spool?
Ps. Once again, white spool of same petg-hf from same order printed with same gcode on same printer produces OK result, so I think it is something wrong with black spool.
Oh well. I think we as users should not accept such issues with not cheap filament.
Hmm if other users experiencing same issue, maybe indeed some batches are bad, how to bring this to Bambu for further investigation? Open support ticket?
For me it was a one time only. Of course bad batches exist, production is never 100% perfect. That was a one time only experience out of 10 rolls of the same brand and color.
In the end i felt bad about not writting Bambu about it because they should know, but also knowing that support takes ages to respond, and my time was not the best, i forgot about it and used it for other stuff.
I think you can write Bambu and attach some pictures. Then you need to wait for their response. Never done that myself
I dried for 10h 65C more, RH is 12%.
I do not have precise scales to measure such small weight loss
Anyway additional drying does not resolve the issue.
To sum up, after almost 24h of drying on 60-65C, there are still dots on printed models in black color only.
Are you using random seam? That’s what the pattern is giving me. Use the slicer preview to see if the dots align with seams or anything else noticable.
IIRC the nozzle is set to 245 for PETG-HF, I might try 250-260, but when I did this it was to resolve nozzle blobs which you don’t appear to be dealing with.
You also dont appear to be dealing with overhangs or big speed changes or I would recommend trying outer wall acceleration 200 mm/s^2.
I would also make sure my filament roll isnt binding.
nope, seam position: aligned.
Increasing temp +10 didnt help (240 → 250)
No overhangs on this model, yep…
Filament isnt binding
I opened a new pack of yellow PETG-HF from same order - and after 6h of initial drying tried this one - all fine!
I start to think something wrong with quality control of black PETG-HF on Bambu Lab’s side…
So, white and yellow - completely fine. Black on exact same settings - issues!
That was my experience with Black too. Out of 2, one was unprintable and used as supports interface only. The other one printed fine even without drying it. Just got it out of the box and print with it. No issues.
I contacted Bambu support and provided requested details. They confirmed, that spool is faulty, so they sent me a replacement spool.
So it is not printer/slicer/dryer/model/settings fault, it is spool itself.
Glad they sorted it out. I should have done the same but i thought that for 1 spool they wouldn’t even answer me… oh well, now my faulty petg hf is almost ending
Sorry to hijack the thread but since this one seems solved and since I can’t post my own threads yet I’ll ask here. I’ve been printing with Bambu PETG HF flawlessly for several prints and spools but my latest set of 4 spools is giving me a headache. Please see these pictures for reference: Pic 1 Pic 2
I changed the k value of one of my prints from 0.025 to 0.035 to test the influence on seam size but then my prints started looking like the pictures. But when I changed the K value back to 0.025 things stayed the same. The main problem with the prints is that the inflill and surface fills are rough. I’ve tried calibrating flow rate to no avail. I haven’t tried drying the filaments yet but I am getting a dryer today and will try that. I was hoping someone has some advice or has seen this before.
if this is going to be any better.
