After a couple weeks of printing with PETG-HF here is an update of my impressions. As others have mentioned the interlayer bonds of PETG-HF seems to be much weaker than standard PETG at the default settings. It also seems a lot more brittle with a lower shear factor even against layer lines. I have raised the temperature for the Green PETG-HF to 265 degrees and the interlayer bonds seem to be stronger (without any threading). I really love the surface texture which to me appears to be in between a gloss and a CF matte finish. I have printed at sports mode and ludicrous mode without any issues, I guess this is the point of high flow materials. I usually use PLA for support interfaces with PETG but I was getting a lot of spaghetti failures. My current theory is the temperature difference between the PETG-HF and the PLA Basic creates a lot of PLA oozing. My fix for this is just to use the same PETG-HF filament for the supports and the support interfaces (this also dramatically speeds up the print jobs, no filament changes). I set the āTop Z Diffrenceā to .3mm and my supports fall off cleanly and no spaghetti. I have experimented with white, red, yellow, and green materials.
I would love to hear otherās impressions of these new PETG-HF materials, especially what works for you optimal print temps and speedsā¦
Hi phodara. I have spent a week using this new Bambu PETG-HF (Forest Green). It prints really great generally, lovely surface texture and I am finding that slowing it down too much when shooting for improved print quality causes issues which is slightly counter-intuitive. Also, like you finding strength, toughness and inter-layer adhesion seems much lower than std PETG. Mitigating that with an extra wall. I have tried printing at higher temperatures but did not seem to get much benefit, so have settled on 256Deg C for now.
I am however really struggling with overhangs on certain print geometry features and at angles that would normally present no problem. Its quite good value, so have ordered another x4 refills as assume Iāll eventually find a solution.
Yes I have noticed for me overhangs and bridging are not as good as standard PETG, but I am printing 10degs hotter than you are. Iām going to try your settings and see if that helps.
Yeah, itās really frustrating, as it seems to be just certain combinations of part geometry with some overhangs and slicer settings where this HF material is not great. The material TDS states max bridge length as just 30mm. My overhang feature is about 60mm wide. I am leaning towards the fan settings being really sensitive, but am also going to try some low chamber heating as on a Qidi. Run out of filament, so waiting for more to continue.
The real mystery for me is why seen at such a low part overhang 40deg angle.
Hypothetically, I am considering getting this filament. Is it really worth it? What type of models does it print best with, organic shapes or non-organic? Also, how good are the supports in its own material from 1 to 10?
For me PETG HF was definitely worth it. PLA was just a little too little heat resistant for a bunch of outdoor parts. I used it for rain catchers on canalis and netting clips to keep birds from nesting on my roof. In PLA I was replacing every year after some minor heat warpage. I also used it for some silica gel bead dryer rings to dry silica gel in a filament dryer.
Pretty much anywhere you need more heat resistance than PLA has but outdoors especially because of the higher softening temperature and UV resistance.
Not sure I understand āis it worth itā - the Bambu PETG-HF is generally cheaper than other branded normal PETG?
I donāt generally use supports. However, on my problem print I managed to do a full 25mm radius about 20mm wide straight off the build plate with bespoke supports modelled in CAD (with a very low clearance distance and lower than normal fans). Normal & Tree supports left too much mess as is the norm, but generally this HF is not oozing / sagging / blobbing so Iād say itās slightly better than normal PETG for support features.
Its much weaker and less ductile than normal PETG, but generally prints really clean and fast.
Finally received a new batch of PETG-HF filament. Think I have found the culprit for my poor overhangs mystery. Updated to Orca 2.2.0 and went line-by-line through slicer preview in my problem areas and a common theme was a rapid change of flow rate / speed, just prior to overhangs on longer portions of outer walls. My previous PA calibrations did not show this problem at all, presumably as the PA Pattern calibration part length is too short, so also intend to print the lager PA Tower to try replicate the problem and confirm.
So, have now enabled āextrusion rate smoothingā in advanced Speed settings with a starter value of 300mm3/s2. Think this setting used to be called āsmoothing coefficientā in previous Orca versions. Quickly printed a small test piece of my part and the overhang finish seems much better. Now away for a couple of weeks, but on my return will print a PA calibration tower + full size test, and tweak the smoothing value down if necessary.
Have also been playing with enabling the adaptive pressure advance (beta) setting, which on the slicer preview seems to have a similar effect on flow rate prior to overhangs as the above smoothingā¦
If one, or both, of the above settings cures my particular problem with PETG-HF, will then trial increasing my extruder temperature in an attempt to improve inter-layer adhesion and other material āstrengthā & durability properties, which I am currently finding rather disappointing. Am hoping to replace ASA with this material for some larger, more awkward parts, as BBL state this PETG-HF is UV-resistant. Purchased x4 spools in the hope I can!!
Wow thatās great detective work! Does this apply to setting within Bambu Studio also?
Sorry, no idea. I am on this BBL forum just for the filament material information. I am driving a Qidi Q1 Pro and an I-Fast, both using using Orca slicer. As Orca is a fork of Prusa / Bambu studio, I would think these settings or at least something very similar read across pretty well, although they might carry different names.
I think itās only for the X1 or there might just not be different variations.
Iām still tryint to get the Bamba Petg-HF to work properly
What does this comment even mean?
I just received light green petg-hf, but I am afraid it is sitting and melting on my window.