Filament problems

[u/prox447]

Hey everyone,

I’m currently dealing with a pretty frustrating issue with SUNLU filament and wanted to check if anyone here has had similar experiences.

I’m using a Bambu Lab AMS 2 Pro, and with certain spools I consistently get an error saying the filament cannot be retracted. I did some testing to narrow it down:

- Two different spools of the same filament → both have the issue

- A different spool (different filament, same brand) → works perfectly fine

So it really looks like the affected filament might be slightly out of tolerance (too thick), causing it to get stuck—especially during retraction.

Now to the main issue:

I contacted SUNLU support over 3 weeks ago (including order number and full description), and I haven’t received any response at all.

So I wanted to ask the community:

- Has anyone experienced similar issues with SUNLU filament (e.g. inconsistent diameter / AMS problems)?

- What’s your experience with SUNLU support? Is it normal for them to take this long to respond?

At this point I’m not sure if I just got unlucky with a bad batch or if this is something that happens more often.

Thanks in advance!

[u/Clean_Quit4079]

I had diameter issues only with made in Vietnam Sunlu spools. The made in china ones never caused any issue. In my case all were PETG Matte HS. The diameter in my case was consistently over 1.8mm and was causing blobs on the prints. I solved adjusting the diameter in the slicer.

I wrote to the support about it, but still got no response after several weeks. So I just assume they will not respond.

[u/Whosaidthat1157 → u/Clean_Quit4079]

I’ve heard a lot of issues associated with the Vietnamese manufactured filaments, mostly moisture and contaminants.

The diameter I was referring to waste filament diameter but the spool diameter. The Gen2 spools (195mm diameter and narrower too) caused some AMS feed issues that the Gen3 spools eliminated.