Edit: Setting the max speed for walls to 50 mm/s solved it! I feel like this should be limited when you select the filament, but oh well.

Hey, so I have recently gotten a Bambu A1 and got a roll of PLA and PETG. The PLA is printing very nicely out of the box but the PETG not so much. Since I’m still very much at the beginning of my 3D printing journey, I don’t really have a good way of drying my PETG yet, I just stuffed it in a plastic ziplock bag with all the desiccant bags I got from the rolls and printer and stored it that way. I’m already planning to print myself a filament enclosure, I just haven’t gotten around to buying the bearings, etc for it.

I’ve done some functional prints with no angled (overhanging) walls and they have turned out pretty good. When printing on supports the overhangs are ugly af, but no weird pattern like this.

The issue I’m tracking down seems to occur on ~60+° overhangs, that really shouldn’t be an issue. I’ve done a sliced test print and took some photos, any idea what causes this?
Thanks :)

Bambu A1, standard 0.4mm nozzle
Bambu PETG Basic filament and profile using Bambu Studio
Some settings I played around with was flow rate (0.94->0.95) and layer height (0.2mm -> 0.15mm) but it seems to make no difference.

(note, on some of them the part is photographed upside down.)

  • TragicNotCute@lemmy.worldEnglish
    3·
    9 months ago

    That’s wild. As you’re watching it do this, do you notice anything unusual? Sorry I don’t have an answer, but maybe some engagement will help.

    • Jawa@lemmy.worldOPEnglish
      3·
      9 months ago

      I tried to observe it but it just goes straight over it… It seems a bit like a cascading issue, where one layer has a bit missing and then the next one blobs onto the next because it’s trying to print on nothing, idk

      It also sometimes catches itself again and you get these patches of weirdness and then it’s okay again

      • bigredgiraffe@lemmy.worldEnglish
        2·
        9 months ago

        I agree with the other poster, this is wild. It seems like It is limited to one axis so maybe it’s a slicer or printer bug. Does it do it if you print it out of PLA? PETG is cranky all around but I have never had it do something like that hah. Is this part online somewhere? I can try to slice it and see what happens on my x1, I’m curious now haha.

        ETA: you should also open a support ticket, they have great suggestions sometimes.

        • Jawa@lemmy.worldOPEnglish
          1·
          9 months ago

          Thanks for the input!
          So the thing I was trying to print was this: https://www.thingiverse.com/thing:6365845
          Ideally you’d just print it in PLA but I only had one colour PLA so I thought, might as well gather some PETG printing experience :D
          The part in question is red_panda_low_poly_V1_-_head_A_red.STL and I tried to print it on an odd angle to make sure that most of the outwards facing walls were on the top, because anything that needed support turned out so hideous.

          Also it seems to appear on any side of the model, where you have a slight overhanging angle, in no particular axis :)

          I’ll print it in pla once my current print is done :D

          • IMALlama@lemmy.worldEnglish
            1·
            9 months ago

            PETG can do supports, but it’s not pretty if you have steep overhangs. It’s also kind of annoying to sand, but you can do it. That said, if you have a heat gun or hot air station you can get a lot of the surface shine back after sanding by warming the surface of the print up a little. You do have to be careful to not overdo it though, otherwise the model will deform.