Hey everyone, I’m running into a frustrating PETG HF issue and could use some input.
I’m printing on an H2D.
I’ve dried the filament twice already, so moisture shouldn’t be the problem. It’s sitting in my AMS Pro at around 16% humidity. Despite that, I’m still getting quite a bit of stringing.
I’ve done both flow calibrations as well, and my K value is at 0.019. I also ran a full retraction calibration, but it didn’t really improve things.
What’s strange is that the strings are especially noticeable along travel paths where they intersect with outer walls — almost like it’s oozing just enough during movement to stick there.
One thing I’ve noticed that confuses me:
During retraction testing, a spool with less filament (more toward the inner windings) gave me noticeable stringing. But when I switched to a new, full spool using the exact same settings, the stringing was basically gone.
So now I’m wondering:
Is it possible that even after drying, only the outer layers of the spool are properly dried, while the inner filament is still holding moisture?
I’ve attached all my settings, including filament settings. The filament temperature is based on Bambu’s recommendation for printed parts (PETG) and support PLA.
Has anyone experienced something similar with PETG HF on Bambu machines? What actually fixed it for you?
Really appreciate any insights 
Hi LL,
Yes, that was my exact experience after drying my first roll of PETG HF black in my AMS HT. Started great, went down hill. It wasn’t as bad as yours looks (sorry!), but the quality clearly deteriorated. I re-dried the rest of the roll, and it got all better again. I got a different dryer (other reasons as well) and haven’t had that issue since.
Not saying that’s necessarily the issue, or only issue, here, but just to share my experience on that specific question.
Personally on my H2C I haven’t had to adjust any of the BL HF filament settings for any of the nozzle sizes (well, definitely not things like retraction or even flow rate). I do like to slow things down (in project Speed settings), and also accelerations. But that doesn’t really affect stringing.
Cheers,
-Max
Hi Max,
May I ask which dryer do you have right now that eliminates your problem?
I saw the same issue with 0.6mm high flow nozzle in this forum. What is your nozzle diameter?
Well, as I said on another thread yesterday, I’m hesitant to make product recommendations. I got a Pi X4, but I’ve only had it a few months and a couple dozen rolls. It has worked fine so far, better than the HT and Pro AMSs I own (the internal temperature seems more accurate, for one thing). It’s still a plastic oven though, with little insulation (I cover it with an old thick towel while drying, w/out blocking the exhausts).
I’ve used “all” the nozzles with my H2C… .2 through .8, high flow and regular. Mostly now I use .4 & .6 HF (because I have them, for both sides), but I didn’t have any issues with the others.
-Max
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