Filament fail PETG-CF

Bambu Lab X Series Bambu Lab X1C
1

So we started having layer adhesion problems with our prints on the X1C. All Bambu PETG-CF, ran thru a dryer at 60c, new extruder, new hot end, tried four different rolls with no luck, parts kept breaking. Tried another brand and the strength is back.

2

Try running the Bambu stuff hotter.

2 Likes
3

So I tried the Bambu PETG-CF 262c & 265c, both failed 1st layer. 268 looked great but the part was still weak. Trying 280c now.

Tinmorry worked at 255.

4

I use these settings for both all Bambu PETG (HF / CF / GF), and they seem to work for me. As always, your individual milage may vary.

  1. Dry your PETG using the built-in filament dryer routine in the X1C. Yes, it may take forever (~12 hours), but it was worth the wait.

  2. If available, load your filament into a pass-through filament dryer (I use a SUNLU Dryer Box S2), set @ 55°C. I have my filament exiting the dryer box with a (comically long) PTFE tube running all the way from the dryer output to the back of my X1C (using the optional 4-in-1 PTFE adapter), bypassing my AMS.

  3. Changed the following settings in the default PETG profile (and made it a custom user profile instead)

  • Print temp (for all layers): 265°C
  • Increased build plate temp to 80°C (using BIQU CryoGrip [gray] plate…and yes, 80°C works just fine on this plate)
  • Lowered max volumetric speed to 10mm/sec
  • First layer speed: 40mm/sec
  • First layer infill speed: 80mm/sec
  • Outer wall speed: 125mm/sec
  • Inner wall speed, sparse infill and internal solid infill: 200mm/sec
  • Top surface speed: 150mm/sec
  • Overhang speeds:
    • 20mm/sec (25%, 50%)
    • 20mm/sec (50%, 75%)
    • 10mm/sec (75%, 100%)
  • Gap infill speed: 200mm/sec
  • Changed wall generator to “Arachne”
  • Set sparse infill pattern to “Gyroid”

Finally, I print with the top cover off and the front door completely open (like I was printing with PLA). Use no glue / supertack on the plate. Once the build plate cools down to room temp, my PETG prints come off super easy.

Some of these changes (like Arachne walls or Gyroid infill) are no-brainers, but I absolutely swear by these settings. I use these settings with a 0.4mm nozzle and print at 0.12mm layer heights, and I get silky smooth prints every time. If I’m feeling froggy, I’ll use these same settings, but load my PETG-CF in my AMS and use PLA as my support material, and still get great results.

5

Thanks for the tips, but at this point I plan on never buying Bambu filament again being a filament at half the price worked on factory settings. Bambu PETG-CF used to be just fine, they must have changed something.