Nah, he wasn’t referring to you, several of us started talking about alternatives to PETG and went a bit off subject. It wasn’t you! 
5 Likes
Ok guys, this might be the last attempt until I return the printer! I need your help!
Bambulab support is a waste of time! Seriously. I did everything they wanted. Last thing I had to do is to print a part without any features! Man, I know the printer prints ok if there are no features at all! I knew that 2 months ago!!!
So far its quite simple. My X1 prints PLA in perfect quality. Everything else does not work at all.
I even bought another spool of PETG from a different brand, same problem.
I even bought a spool of ASA filament, same problem.
Could you help me out printing the following part with PETG with generic profile on your X1 (or P1P) and then post an image?Dropbox - test_sample_15x15x30.stl - Simplify your life
I need to proof Bambulab that usually the X1 prints fine! But I need more than just 1 sample!
Thanks for your help!
1 Like
heres two pics, one is an in progress part printing out of esun cheap petg. First off i had a few issues but ended up going step by step bit by bit and got it working well.
the second pic is comparing pla vs cf nylon vs petg.
I have zero 3d printing experience and only used stock settings intially but then changed bit by bit based on what others have suggested and what i experimented with. i run it hot. hotter than esun suggest but it comes out nice.
my part fan is off on the first layer entirely with my chamber fan on 40% or higher and the aux fan comes onto 10/30% after the first few layers.
Again forgive me if this isnt really helpful for you, but i find mine is 99% of the way there so far to being spot on.
Okay, T_guttata, I printed the 15x15x30 file about 6-8 times to see what I could see. I have an MK3S+ and an X1C, so I wasn’t worried about moisture or color or whatever. I used grey since it shows everything.
Incidentally, I’ve been using an Eibos single roll filament dryer with a built-in fan. 45W and it works great. There’s a display which is actually just a battery-powered hygrometer, but operator setting consists of a simple knob to select the filament type (aka temperature knob). I put PETG in for a couple hours, so maybe 0.10 kWh to dry.
Anyway, did some test prints. I have 5 of them which are described here:
#1 As close to Prusa’s PETG technical data sheet as I could figure out (PrusaSlicer gcode specifies 0.080 PA!).
#2 Generic PETG profile with a pressure advance of 0.048 (determined from the SoftFever PA calibration lines).
#3 Generic PETG profile with 3dball’s settings and pressure advance of 0.048 (per my line test).
#4 Created using Prusa’s PETG technical data sheet but with pressure advance of 0.048 (per my line test).
#5 Created using Prusa’s PETG technical data sheet but with pressure advance of 0.020 (sheer curiosity since this is the PA used by generic PETG).
Ignore the horrible appearance of the base on #1. Using engineering plate and got lazy with the glue stick. First layer didn’t stick great, but it was the last print of many and I was tired.
And the settings for #2 and #3 are here (PA didn’t appear since it was 0.048 for both) :
Finally, here are generic PETG and the “Prusa TDS” compared:
Note that “temperature of vitrification” is sometimes called “solidification temperature” which is listed as “heat deflection temperature” in the TDS. 68°C FWIW, the TDS is where I got most of my settings data.
Also, it helps to slow down your first layer unless you’re using the textured plate. PETG is tough, but it will pull free from the smooth build plates without hesitation. Finally, I had to leave the door open per Bambu Studio’s software prompt. It seemed to work.
Last thing. Prusa has a guide on Linear Advance, and it has a bunch of images that may look familiar…
4 Likes
I have exactly the same strange artifacts always starting at the top right corner of a hole. These were done in stock PETG settings with PolyLite PETG Gray.
I will try to adjust some settings, but this might well be a software problem.
Question: Did anyone try to slice the STL in anything other then Bambu Studio? Cura maybe?
2 Likes
Ok,
I made some settings adjustments in the slicer and it solved my problem. Being an absolute newb in 3d printing maybe has some advantages. 
What I wondered was that the print always failed at the same point, either the line line right before the bridge of the hole or the bridge line itselt.
My first idea was acceleration and travel speed, so I reduced them to 200mm/s and 1000mm/s². I got the exact problems as before.
Next I disabled Slow down for overhangs and massively increased Bridge speed t0 200mm/s and all the artifacts had been gone.
From the damage to of those affected lines, I guessed it might be some filament oozing out of the nozzle and hardening too fast and either ripping the layer below apart or at least preventing the actually printing layer to stick. So I reduced the time spent for bridges and overhangs, fan speed settings might also help to finetune, but I left mine at stock.
It is just a guess, I would need a much better camera with lots more fps to validate this, but at least I can print this STL now. Its not perfect yet, but at least a good direction to improve on.
@T_guttata Would be great if you could validate the settings and get your results here as well
21 Likes
Yup, for sure not a software problem or we’d all be having it. Glad to see you make such a big improvement with just a couple of tweaks, especially for being so new. It doesn’t take much to start building your confidence, you’ll be a pro in no time at this rate.
PETG is very sensitive to speed. Too fast and you get under extrusion and poor layer adhesion. Too slow and you get over extrusion and blobs.
The next settings you’ll want to work on to improve your finish will be the retraction speed and distance. So when the printer does overhangs, it stops printing filament. But, there is still liquid plastic in the nozzle that can ooze out when you don’t want it to because you’re doing an overhang (or traveling the nozzle it to another location while not printing). You can combat this by having the extruder retract the solid filament a certain amount and at a specific speed, which will pull it back and will suck the blobs back before they escape. You don’t want to pull back too much or two fast, as that can break the filament or cause other problems, so you’ll want to run some retraction tests to get your optimal amounts for this particular filament.
Fast Stringing / Retraction Tests
In the simplest terms, you want to print one of these quick tests and tweak the settings up or down until they keep improving. These are meant to show you stringing as the nozzle moves from one spot to the other. When your retraction settings are dialed in, you won’t have any strings.
Keep going, you got this.
5 Likes
@ Thrawn
THANK YOU!!!
You are either a lucky fellow or a genius!
I only changed two settings: disable slow down for overhangs, increase bridge from 50 to 200mm.
I did not change any other acceleration or speed values.
All artefacts are gone!
Quality is perfect!
17 Likes
Glad to hear. Might need some more tinkering for other parts maybe, but at least there is now an idea what might be causing it.
2 Likes
I just got interested in it and digged and testet some more. It actually is the slowdown for overhangs setting only, as no bridge is detected in the slicer. A moderate increase in speed for the 50%+ overhang speeds to 25mm/s removed most of the artifacts already, so setting it slightly above to 30mm/s should be enough to avoid it and the risk for problems in other prints with larger overhangs should be less then simply disabling the slowdown.
5 Likes
One question remains: why do some X1C machines require this tweak and other X1C machines don’t? Is it just some kind of borderline variability in manufacturing?
2 Likes
Remember what I wrote in a previous reply of another thread you made regarding this issue ?
We can learn something from everybody
This is a perfect example as there’s people in here with many years of experience that were throwing ideas at you and non of them seemed to be helping
Then along comes an awesome suggestion by @Thrawn who openly admits to being a newbie at this and presto ! the solution is discovered
Nice work Thrawn and I’m stoked you finally got a solution to your issue @T_guttata
Like a few of us wrote in our replies, hang in there and the solution will come to you
It’s these kinds of little things that put a smile on my miserable face lol
8 Likes
That is quite a good question, and I got absolutely no idea. But in the few weeks since I got my first printer, I learned there are so many variables that its not easy to find a general answer to many problems.
Could be filament, could be ambient temps, could be nozzle manufacturing variances or a ton of other things.
I didn’t have any problems with other PETG parts I printed, so I only printed the the test cube to provide a photo that it works…well, turned out it didn’t
1 Like
Sooo many variables. Different filaments are heated at different temps, different ambient temps, different enclosures for P1P vs X1C.
That’s why you got to tune your own settings.
2 Likes
So hopefully Bambu Lab is reading this and will update the generic PETG profile to help others!
1 Like
I am happy with the present petg profile. It works great for me.
2 Likes
Seems that PETG is finicky and can be quite different between brands. I really wish Bambu Lab would allow us to develop our own filament profiles that we could assign to AMS slots instead of using “generic PETG” for the slot and having to select the profile for the project separately.
2 Likes
I will certainly let Bambulab know the problem is solved.
If a setting is causing such huge artefacts, bambulab must rework their settings. Tweaking some parameters will always be required, but in this case I would not call that “tweaking”.
Would be very interesting to know what really has an influence and why not all user seem to be affected. To say there are two many variables is not correct, you only have to say that if you don’t understand the technology in depth.
It can completely ruin your print, as it can be seen for example here:
A generic profile must not at all contain settings which in some cases can completely ruin the print.
1 Like
@T_guttata A+ on your persistence in pursuing your problem for as long as you have and for reporting back to everyone. 
2 Likes