After watching a Youtube video in which the Bambulab PETG-HF filament was highly praised and in which it was said that it could be printed just as easily as PLA, I ordered two rolls of it. Well, what can I say. So far, I haven’t managed a single print with the slicer settings supplied by Bambulab in my X1C. What’s more, the spaghetti detection also failed when I tried to print a larger aperture for my telescope, so that in the morning I was able to throw almost an entire filament roll of this PETG-HF in the garbage can. The normal PETG prints flawlessly, which is why I personally will no longer use the PETG-HF. It’s no good!
PETG-HF is in fact good. I have had very few minor issues with it but I follow the requirement of drying it well first.
Not sure that’s what went wrong here because that seems like and exceedingly simple model. Is that cylinder graduated? Maybe its just the perspective.
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I personally don’t think your problem is wet filament as from what can be seen in the picture it looks fine right up until it explodes.
And while I personally don’t like and will no longer use PETG-HF for entirely different reasons, from my experience what happened there is definitely not normal. The one thing it has going for it is the fact that it prints really easy and well.
If you try again with it watch it while it prints and maybe you can get a better clue what’s happening.
There’s a little mounting boss or something next to the build plate in the good part of the print that looks like it was also having minor issues.
Did the model come loose from the build plate? If so, it can cause that kind of thing. Build plate cleaning trips up a lot of people.
Also, there were some comments a while back on how well different colors of PETG HF printed and IIRC, black is one of the slightly more problematic.
You don’t mention drying but so far, all filament I’ve bought from Bambu came with free water. Pretty much all filament does. Vacuum bagging with desiccant may help but it’s all had some amount of moisture.
PETG HF is noted specifically as being recommended for drying before use. It makes a difference. How to dry is a whole other topic because manufacturers recommend drying using special commercial ovens which most of us don’t have.
Anyway, the only difference between these prints of white clips is the problem one is before drying and the good print is after. Drying got rid of the doughy surface look and the corner lifting (moisture can affect build plate adhesion). The last photo is peanut brown PETG HF printed into a water catching funnel after drying. You can see the smoothness and uniformity of layers with no spaghettI. Zoom way in and you’ll see the layer lines.
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The X1C records video of prints by default, right?
Does reviewing the video file near when the failure started reveal anything that might help diagnose the problem better?
Ouch! That looks like a multi-hour print—it must be frustrating to see it fail like this. I feel your pain and frustration. 
As @MZip pointed out, did the model come loose from the bed during printing? You might consider increasing the bed temperature by 5 to 10 degrees to improve adhesion. Also, just to confirm, did you wash the build plate properly with dish soap and very, very hot water rather than relying solely on IPA? 
Since the model printed fine for the first third, it suggests the filament is working as expected. The last two-thirds, though, is a classic case of the model slipping off the plate. Once contact with the surface is lost, recovery isn’t possible, and spaghetti is the inevitable result.
I’ll be the first to admit I’m not a fan of Bambu Lab’s overpriced filament. But, credit where it’s due—they got the formula for high-speed PETG right this time. However, as usual, they still missed the mark on the factory default settings. While the defaults work, they’re far from optimal; I achieved significantly better results by fine-tuning them.
That said, the issue here still seems related to the model losing adhesion to the build plate.
In my tests with grey PETG-HF, it performed decently but not noticeably better than the Elegoo Rapid PETG, which costs substantially less (about 40% less). So, unless you specifically need the fancy spool, I’d say Bambu PETG-HF isn’t the best value compared to alternatives.
On the subject of spaghetti detection failing: I don’t own an X1, so I have no firsthand experience. However, based on numerous reports on this forum, it appears to be a flawed technology. It seems to perform especially poorly with certain filaments, particularly where there is low contrast, like black on black. Testing another PETG-HF color to see if these issues persist would be interesting.
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I have made several prints with PLA without major problems, now started trying out that PETG-HF. The first one was fine, but I noticed that sometimes there is thinly extruded filament attached to the nozzle while it’s moving around between layers.
I tried a Benchy from the official sources to try some YouTube advice that boiled down to playing with the layer heights to compare the quality of the result. My first attempt immediately bombed on the second layer, with a large piece being dragged around while it started, then getting stuck somewhere near the middle, and the nozzle even bumping into it several times. I aborted the print, but had trouble finding any advice on it as I also do not know how to call this.
I’m willing to accept that the “Quality” layer setting triggered this, but unsure as to the cause.
The printer and filaments are all straight from the BambuLab store and new.
(Sorry if this feels like photobombing this post, but it sounded related to my issue and my account is too new to be allowed to start new posts)
Filaments can have “high” moisture content right out of the shipping box and bag. PETG HF that I’ve gotten from Bambu is no exception.
PETG HF is also a bit “sticky” and likes to stick to the extruder. There was a rash of extruders growing big globs of filament recently that pop off the extruder covers and encase them.
Someone posted about “Slice Engineering Plastic Repellent Paint Repels Plastic & Prevents Buildup on the Nozzle“ and my bottle just arrived yesterday but I haven’t tried it yet to comment on how well it works but others seemed very encouraged. I got it on Amazon.
The last part of this seems like it could be moisture related. PETG HF looked like it was trying to curl more when exiting the extruder when I was printing with it and it wasn’t quite as dry as it should be. I was trying not drying it as much to save some time and think it was a consequence but didn’t look at it systematically. May or may not also be a factor but PETG HF got a lot better behaved after drying it well.
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Ok, thank you. I did not realise I would run into a “you need to dry your filament” situation this quick. I think I’ll try the printer’s own drying mode first before telling my wife I need yet another apparatus. Just hope the non-high temperature spools are ok. Buying 4 refills gets you 1 of those at the moment, but I have mostly the regular light-grey coloured ones.
Word of advice between married men: don’t tell, just do. Then you take her out for a lovely dinner time some place she likes, and your “problem” is solved.
Nota bene: It’s wise not to make use of, or rely on, this approach to often…or else the positive impact you seek will be lost (for ever gone).
Good luck mate (from what you say, you gonna need it )
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I don’t know your filament is “wet” but all of the Bambu PETG HF I’ve dried so far has been. If you aren’t drying it then it’s a good chance that’s your issue.
On filament dryers and using the printer to dry, results will depend on your ambient humidity. Ambient humidity imposes a floor you can’t go below when drying filament. If you have high humidity, you may see mixed or minimal results. This is probably the reason so many have such different experiences with filament and the anecdotes and experiences are so varied.
Battery powered hygrometers are really cheap now but there are two main branches in the market. Many of the least expensive hygrometers can’t display values below 10%. When humidity goes below that value they just display 10%. Others will read down to 0 or 1% RH but at the extreme response gets slow and accuracy likely isn’t great. But its own numbers compared against itself should still be useful if you are able to get below 10%.
Another thing to do is just put a fresh spool and a hygrometer into a ziplock bag or polyethylene cereal storage box and let it sit for 10-12 hours. The moisture in the spool will equilibrate with the moisture in the small amount of air in the bag and the hygrometer will come to read the “humidity” of the filament. It’s not a direct measure of filament moisture but is an indirect measure. If you’re seeing 30% RH or above it’s probably too high.
My drying is different from most others and if I do that test my spools pull down below the 10% my hygrometers can read. Fresh from the bags they’ve been above 30%.
All that drying, just to splash it with water again 
They should be fine. I think it’s getting on the cusp of what the non-high temp spools are okay with. I’ve dried them in the non-high temp spools though.
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Ironic, isn’t it? But those rain catcher funnels work great! We don’t get much rain here but my rain barrels fill fast when we do! Once printed, PETG HF doesn’t seem to mind water at all - so far. 
I’m having similar issues with generic PETG from Matter Hackers. Brand new spool of material was installed after drying for 7 hours. Used default settings. Seems like the nozzle is bumping the part as it is built. Surfaces seems very uneven as well. How do I fix this?
On the infill or do you see edge curling?
Always use non-crossing surface and infill patterns (Monotonic line, gyroid/honeycomb,…).
Would need more details (pictures, failure observations, …) for better troubleshooting.
The part seems like it is fairly flat, no curling. Images attached of the build and settings.
I’m using Rectilinear for Top Surface, bottom surface, and internal solid infill pattern .
Thank you.
Ok, that does look like several different issues at play. However, I do not have experience with the Matterhacker PETG. Is it a high flow filament? And do you use the “Generic PETG” filament profile?
I would suggest to try slowing all print speeds to 100mm/s or less, enable “wipe while retracting” in the filament settings and of course change all surfaces and infills to non-crossing infills.
But take that with some caution. As I mentioned, I have not printed with the Matterhacker PETG. At worst though, your print will take longer but should be improved. When I struggled with PETG Basic, I found it better to have one good part rather than two to three bad parts in the same time.
Thanks for the input. I’ll re-run the part again with the settings that you suggested. I did check and the wipe while retracting is already enabled.
I’m using the X1E system.
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Part is running now. I have it set to 0.12mm Fine since I’m looking to have a fairly cosmetic finish. It appears to be building better (fingers crossed). Build time has doubled with the adjustments to the speed settings. I would think that the default settings for the resolution would take the speed into account and decrease so that a better surface finish can be achieved. Will send update when it is done. Thanks for all the input.
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