I have printed Bambu’s PETG (old version, not new version) a few times before and have tried again today, and the print has a multitude of issues - this is with the same reel as before.
The layers do not adhere properly; the model is really weak after printing, the layers in the X and Y direction don’t bond well, but they do seem to bond fine in the Z direction. If you stress the model the layers separate and turn into ribbons in the Y axis.
The filament is not sticking to the previous layer properly, leaving holes and bits of protruding filament. Infill is especially bad, and essentially doesn’t work at all.
The print bed is scattered with bits of PETG whilst printing is in progress that have been hit off of the model where it hasn’t bonded properly.
I have dried the filament for 8 hours at 65C, which made no real difference.
I have previously printed PETG with no problems at all, and PLA was fine last time I printed.
Any ideas what has happened? It’s almost like the presets are wrong, but I have the AMS and it’s auto-filled the correct filament.
How did you dry it? The common filament dryers don’t work that well because they don’t exchange the moist air inside them for outside air. And worse, with hygroscopic filaments, a filament dryer can even add water to filament on humid days. Propping the door/lid open helps on low humidity days but not so much on humid days.
It’s been in a Sunlu S4 dryer, which claims the humidity when cool is about 30%, it was 14% when hot. But yes you’re right it doesn’t exchange the air. I tried PETG brand new straight out of the packaging though so shouldn’t have been damp to begin with.
Shouldn’t have been but some have reported humid filament right out of the vacuum bag.
Most spools I’ve used right from the bags have printed fine though. But in recent testing working out an air dryer for filament drying my Sunlu S2+ added water to the filament when I tried drying on a humid day. That’s what pushed me down the road now looking at how to dry air for filament dryers.
try to ramp up the temperature for “other layers” (all except first layer) from 255°C to 270°C. I posted this several times in the forum as this is the only way I can print with Bambu PETG. If I stay on 255°C all my PETG prints look like yours. Just give it a try.
