I’ve been printing with a Prusa MK3S+ for about 3-4 years now, and the only print material failures I’ve ever had were my fault (print set for PETG but loaded PLA or vice versa). I expected the same or better quality from the X1C, but I have a 75% failure rate with PETG, either from first layer adhesion to spontaneous spaghetti. First it was the default textured PEI build plate. It has zero adhesion. When I added glue stick (provided by Prusa for the old printer but never had to use) the prints would stick and my success rate went up. I never used the glue stick on the Prusa and I rather not have that hassle, so I got the new Bambu cool plate SuperTack, but my first print’s first layer detached after about 3 layers put down.
Then, even with the glue stick, I was still experiencing random spaghetti. I had a print that used organic supports, and about half way up its 1.5" total height, the organic tree support just sort of split in half and fell over, leading to spaghetti (video here: video_2025-03-23_08-31-51.mp4 - Google Drive). As a test, I loaded the exact same model into PrusaSlicer, with organic supports, and printed it on the 3MK3S+ and it finished flawlessly.
What could be going wrong here? The X1C is about 3x faster than my Prusa, but if I have to print things 3+ times to be successful, it doesn’t really matter.
Hi, i am running 4 X1E and 1 X1C at Work. I had similar Problems several Times.
In every Case so far the Nozzle was slighly bent. Pla ist fine, but no Chance in PETG. Printed one of the many Nozzle Checks and now its running again.
The Bambu printers like the X1C are quite different from older printers like the Prusa MK3S+. The faster speeds require a bit more meticulous handling of your build plate and filament. These speeds can exacerbate issues like bed adhesion and printing other printing issues. From many users experience, don’t try to treat these prints like the older printers, as you won’t get the results you expect.
Most of the time the issues you describe are related to two common issues that many people overlook; especially those who are not used to these newer printers.
- Clean your build plate! This is arguably the number one issue that users experience. Take the plate and wash it under hot water, scrubbing with regular dish soap. Rinse it off until you see the water start sheeting off of the surface. You may need to do this a few times to get it fully clean. Here’s a couple of links that may help you with bed adhesion issues: Bambu Lab Textured PEI Plate Troubleshooting Guide | Bambu Lab Wiki and First Layer Not Sticking: Causes and Solutions | Bambu Lab Wiki
- Dry your filament! Hygroscopic filaments, such as PETG, are very prone to all kinds of printing issues when they retain water. With how fast these printers run, they tend to amplify wet filament issues and so you need to dry and keep dry these kinds of filament. Here’s a good link with drying recommendations: Filament Drying Recommendations | Bambu Lab Wiki
Try these two steps and you’ll likely resolve much of your problems. You also may want to keep this general printing troubleshooting guide in your back pocket: Common print quality problems and solutions | Bambu Lab Wiki.
The main thing that’s overlooked in the vast sea of observations is the fact PETG is viscous and sticky.
Long story short, just add G29.1 Z0.03 to your filament start code. PETG has to be plopped down, it cannot be laid/smeared like other filaments.
What are the nozzle checks? I thought it might be some of the self tests available on the machine LCD, but I don’t see anything there. Is there a page for this (maybe Nozzle/Hotend Unclogging Procedure for X1/P1 | Bambu Lab Wiki)?
I’ve been religiously scrubbing, but I realize I didn’t clean the new SuperTack plate. I haven’t dried my filament, but the filament I was printing with came right out of vacuum seal and into the AMS, with its new desiccant packs. I’ll try drying it out anyway to see if that improves things.
Unfortunately fresh filament does not mean it’s dry filament. Even Bambu recommends drying much of their technical filaments before first use. This is directly from Bambu’s website for their PETG HF.
I’ve just made it a habit to dry everything after first opening and then storing it with desiccant. Has greatly reduced most of my print issues I used to encounter.
Do not trust that your filament is dry when you receive it. Repeat: DO NOT trust that your filament is dry when you receive it. People get spoiled by PLA because it is so forgiving, but most other stuff requires more care. You’ll save yourself a lot of pain and suffering if you just assume it’s all wet.
Being a lot faster, the current gen printers are much more sensitive to filament rheology and minor contamination of the build plate. It is not uncommon that the textured plates need several good scrubs with a hard, clean brush, diswashing liquid and plenty of water. Especially when switching from PLA to PETG and vice versa.
With PETG, you really should consider it saturated unless self-dried.
Curling and warping are good first indicators for moist filament. They are also two of the main causes for bent nozzles when printing at high speed.
I’m using Sunlu PETG High Speed, and haven’t ever dried it and it works perfectly…now. Out of the box, not so much.
But, I ran all the Orca Slicer filament calibration and dialed it in, and have had no problems since. One thing I can say is that you need to run the calibration in the exact same environment where the printing is being done.
I had first run calibration in a room with about 5°C higher ambient and slightly higher relative humidity. Then, the printer got moved to its final location, and PETG was a mess again. After calibration again, it was perfect, and has been ever since. I have pulled new rolls out of the box and just printed, because Sunlu seems to be very good at maintaining the same filament chemistry across different rolls of the same material.
Did you try creating a custom PETG profile and setting bed temp to 80C
I’ll echo others. Dry your filament and keep the bed clean. I do everything I can to not touch the PEI bed and if I do, a quick spray and wipe with IPA to keep greasy finger prints off. I print almost exclusively PETG (generic and Bambu HF) and only have issues when I have touched an area and forgotten to make sure it’s clean.
Thanks @colonel0000 and others. I dried the PETG filament for 12 hrs in the Bambu (and ordered a Sunlu S2 for the future) and reloaded it into the AMS. I then scrubbed the SuperTack plate twice with dish soap and water, and dried thoroughly. I then started a print, and immediately, the test strips at the front of the plate failed to adhere. Half of them just lifted up after the nozzle finished laying them down. Same story for a 1" circular mat it started in the middle of the plate for a large organic tree support; the filament stared to lift up and away. Not sure what the SuperTack is meant for, but somehow less sticky than the PEI plate.
I then switched back to the PEI plate and slathered it with the glue stick I’ve used in the past. Starting this print, the test lines went down fine (and there wasn’t even any glue stick in that area), and the first few layers seemed pretty good, but then I realized that a section at the far end that was harder to see on camera had lifted up and was turning to spaghetti.
At this point this feels like I have a lemon. I’ve done all the calibration tests available via the machines LCD interface, and frankly, I don’t think I should have to download other programs, with other calibrations, or insert g-code into my files to get a highly rated, newly released $1500 machine to print what I consider a very basic material into very basic shapes. I really do appreciate the help everyone’s given, but I think my next step is to contact support.
It’s a super common thing with PETG, don’t sweat it. Just put the G29.1 into your start code. It’s not a printer thing, it’s a PETG thing. Since the dawn of time PETG likes to stick to 2 things, other PETG and the nozzle.
Too early to write off the printer 
Printing PETG is a very different on the Bambu’s than on prior gen printers. I already mentioned the textured plates peculiarities and the need to dry but indeed there are quite a few more things that can/need to be done to get complex (what is complex/simple with PETG?) prints to finish adequately.
First is cooling. This was a big problem when PETG Basic released as the profile was just wrong. Nowadays, the first thing I do when preparing a print is to copy over the Generic PETG cooling settings. While I am in the Filament settings, I also enable “wipe on retract”. It reduces end of line defects bumping/clinging to the nozzle on the next pass.
The next item is to consider PETG’s desire to cling to the pretty much anything not PLA. Including heat. I have the impression it is slower to cool, making it worse in bridging, overhangs and giving it a desire to curl. The latter is a common failure root cause for late print errors such as support collapse.
Support collapse is common with PETG if supports are slim and weak (increase support wall count, use a honeycomb infill in extreme cases, make the support base wider and add support brims) and curling occurs higher up.
Curling itself is a cooling problem but it can be better tackled by slowing the heat input. You can achieve the latter by reducing layer height (adaptive layers are great for this as curling is more of an issue on larger overhangs) and/or slowing the print speed.
While I am not so experienced with PETG HF, my experience with PETG Basic and failure case observations have led me to usually slow PETG Basic print speeds to <80mm/s, <120mm/s for PETG HF but I may be overly cautious on the latter.
Unfortunately, I can not comment on the supertack. Mixed reports in the forum led me to go without it.
So these are just some of my key experiences with PETG in the hope that it may be helpful to you.
&
PS: And of course, never, ever, ever use crossing surfaces and infill anywhere with PETG. It’ll punish that immediately. Always go for non-crossing patterns like circumf, monotonic, gyroid or honeycomb.
Once you get far enough along as well, you’ll probably start having failures from stringing, I specifically spent weeks and weeks designing this for petg, happened to work great for everything else. I’ve had one person say this is the only wiper that works with petg-cf iirc
Okay, for the record, I print a lot of PETG - like 2:1 at least vs everything else. Most of it has been Bambu’s HF. I haven’t had to alter my G-code or use glue stick. Honestly, I’ve got some glue stick and some liquid glue on hand and I literally never use them for anything. I use the textured PEI plate, wash it thoroughly with dish soap and lots of warm water in between prints, and I’m scrupulous about drying my filament.
I’ve had very occasional print failures. A couple due to tall, skinny models, which I solved with brims and the like. Some were caused because of the wiper - I’ve tried various things, and none of them have been perfect, though I haven’t tried kungpao’s version yet. The other set of failures were due to a model that I had designed myself - I reworked it a bit to get more bed contact and the problem was solved.
Like Marvelicious, I have no issues printing with PTEG. The filament I am using is from Monoprice and is several years old. I do dry it and use glue.