I just wanted to share my little experiment. Perhaps it will help you when using eSUN PETG +HS (high speed).
I used the default settings provided by eSUN considering the material properties and the slicing process. I did not dry the material, just used it “out of the box”. First of all I did a stringing test - result: zero stringing, so moisture didn’t seem to be a problem. Yet, I had massive problems with overhangs, so I printed an overhang test: Left Part
Then I searched the PETG issue on the bambu lab forum. There are a lot of recommendations like:
not enough cooling
too high printing speed (outer wall)
deactivate “slow down for overhangs”
dry your filament
Changed part cooling min from 10 → 40% and max from 40% → 90%
Massive improvement: Middle Part
Additionally I changed the printing speed. → deactivate “slow down for overhangs” and set outer wall speed to 60 mm/s
Almost no improvement: Right Part
In the end it just was the part cooling.
Probably you can even tweak it further, but so far I’m satisfied being able to print a 45° overhang.
If you slice with the standard profile, the overhangs will indeed be printed with a 90% fan speed, but that’s ONLY the overhangs greater 10%. The first inner wall, for example, will be printed at the slow fan speed and that is not sufficient for large overhangs.
So my adjustment leads to the whole part being printed at 90% fan speed which is also not ideal, since it has a negative impact on strength.
I hope there sometimes will be an slicer improvement, which sets the fan speed higher for the walls that are two or three away from the overhanging outer wall, so the rest of the part can be printed with the lower fan speed setting, improving strength.
Struggling with terrible overhangs with eSun PETG+HS, I don’t have enough 3d printing experience to know which parameters to be tweaking. I am trying your fan speed bump now…
This was my temp tower using the eSun provided profile:
OK, comparing a part printed before and after the fan speed change, using the eSun profile:
The Good: overhangs look better
The Bad: Weird criss-cross filament left at first layer (NBD), and strength is terrible (Big Deal). Just flexing the part slightly and “crack”, the layers separate. The ugly part printed with lower fan speed takes the flexing with no problem.
OK, this is interesting. I said ‘screw it’ with the eSun provided profile, and tried printing the same part with the default Bambu PETG-HF profile, figuring the materials might be similar enough to make it worth a shot. To my untrained eye the big difference is that the temps are a lot lower for the Bambu filament.
And honestly, that was the most successful print. Not perfect but decently good, and strength seems fine.
I think i’m ditching the eSun settings - I dunno if they are some careless mistake or what, but they seem whack… with the much higher than typical temps (their own page for the filament recommends 240ºC, but their profile has 260ºC), 90ºC plate, etc. If they printed amazing, then I’d accept it, but printing worse than a more normal profile makes me think there’s something wrong.
In my experience with the same filament, eSun profile is just wrong - too high temp and too little cooling.
It prints better with Bambu generic PETG profile - select it and then try printing temp tower. This filament likes a little lower temperature and high flow rate and speeds.
I’m printing at 235 -240, bed 70, flow rate up to 20.
Check this video: https://youtu.be/fhvpshjHYk4?si=mt3j-5418fLHFjQy
I got almost the same values at calibration in Orca slicer.
Only problem I encountered so far is this filament sticks like crazy to textured PEI plate.
EDIT: temp tower printed before calibration with bambu generic PETG profile.
I am a beginner in 3d printing, but I also want to contribute here with my experimentation on setting filament parameters. I bought the eSUN PETG +HS green and did some tuning in the filament parameters that enhanced considerably the quality.
I am using:
nozzle temp = 240C
flow rate = 0.9711
“enable pressure advance” selected and equal to 0.05
max volumetric flow = 20
I added the cooling settings shared here and my overhangs improved considerably.
Note: I haven’t done an overhang testing, it’s based on my printings.
