When printing PETG it doesn’t fill the first couple of layers




Hi! I have some problem when printing with PETG.

I have a bunch of different settings and suggestions from the forum. But I can’t seem to get the hang of it.
When i look at the first two layers or so i can see that it doesn’t fill up all the way to the wall. It stops right before. Any quick fixes for this problem? :smiley:

Have you calibrated your filament yet?

As @JonRaymond pointed out, filament calibration is key. However, I can point to this photo problem here as a classic flow problem. It could be caused by wet filament, too low a temperature or possibly even clogged nozzle or even worn out PTFE tubing albeit the last one is really uncommon.

Two things that you should look at. First, even if you took this out of the bag and put it into service, assume that the filament has moisture. Weigh it then dry it then weigh it again and confirm the amount of moisture you removed. Don’t be shocked if you see from 0.5% to 6% moisture content. My worst was 13% but I started doubting that measurement as possibly being the cardboard spool. Either way, lesson here is do not trust anything until you verified it with your own eyes and instrumentation.

Once you’ve dried the filament, then you can proceed to calibrate the profile on that particular spool knowing that you’re starting out with the best conditions.

If you’re using Bambu PETG, I’ve had a terrible time with Bambu PETG and no longer use it. In fact, I’ve learned that just about every other PETG(my 2nd favorite filament) is better than the expensive stuff I got from Bambu.

Here’s an example of my own misadventure with so-called “Quality Bambu PETG.” It doesn’t look so quality to me. After this messed-up print, I not only had to dry the filament, but I also had to recalibrate the factory default profile from Bambu. And guess what? The Bambu default profile of “their” filament was so far off it was almost criminal. So much for trusting factory default settings.:smirk:

  1. Dry it,
  2. calibrate it,
  3. slow all speeds to 100mm/s or less (you can speed up again a bit once you got a feel for PETG),
  4. stick to non-crossing infills (monotonic, gyroid, honeycomb),
  5. and maybe reduce layer height if you keep having overhang issues (you may want to explore adaptive layer height)

Thanks for the input. After a calibration everything turned out perfect.

Thanks.