I started this hobby last year after a neighbor lent me his A1, which allowed me to successfully build an RC car using 3D-printed parts. After that experience, I decided to get a P2S so I could work on my own designs as well as models from the community.
I had heard that PETG was better than PLA due to its strength properties, but I wasn’t aware of all the issues and challenges this filament can cause.
I followed the Bambu Lab and forum recommendations for drying and setting up the filament, but I’m still facing problems with stringing and poorly formed overhangs (see pictures).
Could someone share their PETG settings? I’m honestly getting frustrated with this filament. I’ve tried all the configurations I could find on MakerWorld and other forum posts, with no success.
I ran a temperature and speed tower, and it seems the filament only works properly between 220–225 °C.
I’ve also tried Arachne, inner/outer wall order, reduced acceleration and speed, and adjusted cooling settings… but nothing has worked so far.
I ran a temperature tower with PETG HF, and most temperatures performed well except at 255 °C, where I noticed a very fine string. While PETG works great for small parts, I’m struggling with taller prints: overhangs fail and stringing becomes excessive as the height increases.
Has anyone optimized settings for PETG HF to reduce stringing and improve overhangs on tall parts? Should I lower the nozzle temp, tweak retraction, or adjust cooling? Any proven profiles or advanced tips would be appreciated.
I had horrible issues with PETG HF until I modified the speeds and filament profile… but I have a tungsten high-flow nozzle, so tweaking was expected. Disabling zhop was a big win.
Did you ever get an answer - specifically, to the first two pictures? I have the exact same issue and cannot resolve it. Have spend hours researching and trying different settings, but nothing has worked.
Thanks for the reply. Filament is dry. Reading 0% - even with a certain degree of inaccuracy, it’s still well with acceptable range. I did slow down the speed and adjust cooling.
The change that made the biggest impact thus far is adjusting quality to 0.16
Ok. Try to go a little down on nozzle temperature, for example if you have it on 255 move it to 250 or 245. Cooling aux fan should be off mainly or 10-20% if you printing small parts. Max volumetric set it at 14, also you can perform a Ksr FDMtest to check more parameters for adjustment if they are needed.
In overhangs what i did, was increase the flow ratio and add supports. With PLA works perfects but with PETG the overhangs are a little complicated to get the print perfect.
Thanks all for the replies and help. I printed the Ksr FDMtest. I decided to use the ‘stock’ Bambu settings, as I’ve played around too much and wanted a fresh start from scratch. There is delamination in the bridge. Doesn’t look ‘bad’, but this was terrible on a tool holder part that had a curved bottom surface. That was with the following settings; part cooling off, max volumetric at 20, nozzle temp 245/255, bed temp 75, initial layer speed 30, outer walls 120, layer height 0.16.
Thinking of printing with stock settings to see what I get and then attempt to tweak from there. Any suggestions are most welcome as this has become very painful!
Thought I would share the outcome of this issue. I printed the Ksr FDMtest, as the initial start, using the default standard filament profiles. I then evaluated the result and followed the recommendations in the Bambu Wiki.
This lead me to printing the printing the Unsupported Bridge Experiments from MakerWorld and followed the process again via Bambu Wiki. Yes, it takes time and filament, but the end result was one of the best PETG prints ever!
For my P2S, using Bambu PETG-HF, the key changes were:
Bridge Flow: 1.2
Bridge Speed: 20
Initial layer speed: 30
Outer wall speed: 180
Inner wall speed: 260
Slow down for overhangs: enabled
Nozzle: 245C
Max volumetric: 20
In case anyone else is having trouble, I’d recommend running the above tests and following the procedures. Thanks to everyone for the suggestions.
Brand new P2S combo. I’m having similar issues with PLA+ with overhangs, bleeding, and stringing. Tried reducing nozzle temp to minimum rec for filament. Retraction set to 0.8mm at 30mm/s. Speed slowed on overhangs. Used various filaments, two were brand new out of the box. Ran all calibrations multiple times.
