Bambu PETG settings not smooth on tested benchy

[CheebiNeko]

Honestly the Bambu Lab PETG for myself was very smooth with my earlier minor adjustments. Only real settings to adjust were the wall speed etc to smooth things out.

All of my cooling etc changes were mostly for the Sunlu PETG I’ve been trying to figure out actually.

Honestly even that is working more or less overall fine out of the box. I’ve had far worse issues with my older ender which was nothing but problems with calibration everywhere with even just PLA. (That printer also came with a lot of problems from shipping that took a lot of fixing up)

The Sunlu PETG had slight stringing, but currently my main issue is the tiny holes I am seeing randomly on the hull or outer walls as I print. Which the Bambu PETG spool didn’t have any issues. And also on those benchy, the first say 10 or 20 layers, the bottom front bow has a deformed state on the left front side which I can’t understand.

I’m actually going to take a step back today and try to re calibrate the Sunlu PETG from scratch. I was reading people had decent results with the generic profile also. I think I’ll start with that and the default .2 process preset again. See how the quality is. Then run through the temp tower, flow rate, and PA tests. Then see how those results turn out for these calibration tests with benchy, cubes, and bridges again. Maybe I was getting too ahead of things on the Sunlu settings.

Also this is making me want to pick up some polyterra and other brands also to try out now lol.

[Alex_vG]

@Alex_vG

One filament brand that I still want try is AOMEI, they have some interesting CF filled filaments (e.g. PC-CF) at a great price.

I was curious myself, because I didn’t look into them for some time. Actually I misspelled them, they are called IEMAI. They have many engineering filaments at a very attractive price and they also provide proper datasheets. The diameter is also specified with ±0.02mm.
They seem to have their roots in industrial 3d printing. On their homepage they sell many high spec filaments like PEEK, PEKK, PSSU and so on and also industrial high temperature 3d printers for processing those materials.

On Amazon germany, they sell the following filaments that I find interesting:
PETG highspeed: 1kg black 20€, 1kg black + 1kg white 30€
PETG-CF: 33€
PC-CF: 50€
high-speed PLA: 15…22€

I haven’t tested any of their products yet, but I ordered the highspeed PETG and PETG-CF. I will report back, when I have some experience with those.

[CheebiNeko]

So I’m glad I took a step back and tried the stock settings to work from. Overall turned out a lot better. Notably more uniform on layers. The stringing is less than the other test. Also the arches, overhangs, and bridges seem better also.

My main issue is I have no idea what’s with the small holes on the outside walls here. Or why the front bow of the benchy has the deformed shape.

Any ideas anyone on what settings might help with this behavior?
I also went through the calibration for flow dynamics and flow rate as well. Which mostly didn’t change anything on me.

[CheebiNeko]

Actually to recap here, I was able to figure it out.

I just finally solved the last problems after all of the back and forth this week. So the holes actually I was able to resolve with the very minor change in retraction to .5 from .8 took care of it. The issue with the warped hull surprisingly fully went away when I swapped to inner/outer wall instead of outer/inner.

I think I had to switch to outer/inner for another print or material and that part got saved and stuck through my presets. It’s looking great now with the Sunlu PETG on the tests. Don’t really see any real stringing or issues with the arches, bridges, or the deformed issues now.

Overall interesting calibration week on this material. Most of the tuning settings through the week I likely wouldn’t even try again unless I wanted to speed things up.

So the following were the all the settings used on this sunlu filament in bambu studio in case anyone else is in a similar boat. Most of the settings I think I kept same from the generic petg presets actually. These are on .2mm quality.

I’m probably going to try to see about bringing the retraction back around .8 to see about getting that last tiny bit of stringing gone. And also maybe play with the volumetric speed scaling once I finish up what I wanted to print currently. But all in all good week lol… Until the other brands I ordered also this week arrive over the weekend to try out from all the talk in this thread on other brands.

[Alex_vG]

Congratulations, that looks great! I’m curious if the changed loop order also solves the holes with default retraction?

The outer loop speed seems overly conservative to me. Have you also tried bigger parts? I optimised PC with a benchy, only to find out that the problems I solved were no issue in the first place when printing bigger parts. layer time apparently plays a role too. Maybe a faster outer loop speed works perfectly fine with bigger parts?

That is also funny with the temp towers. They have such a tiny footprint, that some layers finish within 2 seconds or the slicer slows printing down to snail speed. I now place a big column next to the temp tower, so that it prints the tower at a constant reasonable speed and still takes some seconds per layer. Just while writing, I get aware, that I could save a lot of filament if I size down the column but massively slow down print speed for only the column

The IEMAI filament should arrive today. I will probably find time for it tomorrow and report my impression.

[CheebiNeko]

Yeah I’m planning to check the retraction once all of this print set is done right now.

Quality wise, it feels smoother and more consistent than my first initial part that was done in Bambu PETG actually. Though I’m sure I could fine tune the Bambu PETG further since I spent more time on the Sunlu this week as the early Bambu PETG settings were more or less decent.

This third piece with the Sunlu settings that I did overnight came out overall great. With a tiny bit of stringing.

Part 4 here that I did early in Bambu PETG I can see some layer inconsistencies speed wise. Though it was all smooth and no gap/hole issues or any string issues.
Though compared to the last part it’s not as consistent for all the layers.

Part Number 3 with the earlier Sunlu setting attempt at the higher speed still was the worst, but comparing that to the part number 1 this morning. It’s like night and day on the layer and outside wall quality.

Now speaking of Sunlu, my main gripe I think currently is that their color of black is a tiny bit off between the two spools I had which the AMS used to auto refill.

All in all I need to order more filament to test out Sunlu and their consistency in colors and other material. And also order some more other brand petg to play around and see if any other brands I like more. Though for just personal functional use the Sunlu petg bulk is looking like a great deal at $10/roll for 10 spools.

[Alex_vG]

I did first tests with the IEMAI Highspeed PETG. So in total, I currently have 3 PETG filaments to compare.
My first conclusion: The Bambu PETG is really bad compared to the other too, while I can’t tell yet, if the IEMAI has an advantage over the Sunlu.
Unfortunately, I have the Sunlu in transparent, while the other two are black. I did a speed test with each of them and tried to determine the speed at which the surface transitions from matte (bad) to glossy (good). That is a little difficult for a transparent filament
I started with temp towers at 120 mm/s. Because the temp tower has such a small footprint, I added a cylinder next to it that is printed at only 20mm/s so that layer time is long enough that a layers of the temp tower are printed at the same 120mm/s.
Fan is set to 10% only, aux fan is at 20%.
For the Bambu I settled on the 255 °C as is default. That was the best compromise between nice overhangs and little stringing.
For I the Sunlu, I went with 240 °C. I don’t have the tower anymore to check the decision.
For the IEMAI, overhangs and gloss were completely indifferent with temperature. Only stringing became a bit more above 240°C, so I used 240°C as well.

At the speed test, the Bambu surface starts loosing gloss above 100 mm/s and becomes really rough above 150 mm/s, while the other two keep a smooth surface. The IEAMI looses a bit of gloss above 200mm/s but still looks much better at 300mm/s than the Bambu at 100 mm/s. The transparent Sunlu is a little bit difficult to evaluate, but I would say, it looks quite similar to the IEMAI, with slight loos of gloss setting in a bit earlier.

But the most prominent finding was at the inside of my testprint:
For the speed test, I use a cone with 4 loops, no infill and no top/bottom which is dimensioned, so that the layer time at the base (biggest diameter) at 300mm/s is just the same as the minimum layer time in the filament settings. So effectively, each layer takes the same time and the speed is reduced the closer a layer is to the top.
Now, investigating the inside of the three cones, Sunlu and IEAMI looked fine, while the Bambu had lots of defects and propagating holes starting from 100mm/s and getting worse with higher speed.
That and the rough outer surface lets me think that the Bambu is just not suitable for anything above 100mm/s.
I will print a benchy with the IEMAI now at default speeds, just as a quick intermediate check. That gave horrible results, when I tried it with the Bambu PETG.

[Alex_vG]

Next test finished: Speed vs. Overhangs
Cooling was set to 10% part fan, 20% aus fan.
I created a small model with sharp and rounded overhangs at 40%, 70% (-> ranges that orca / bambu allows to reduce speed for) 45°, 55° and 65°. I printed that at 30, 50, 100, 180 and 300 mm/s.

IEMAI printed perfect overhangs up to 45° at 300mm/s. At 55°C there is slight curling at the top layer, which gets a little bit better the slower the speed. But it doesn’t disappear completely even at 30mm/s.I will repeat with more fan. The 65° was never good. at 30mm/s it keeps up ok the first few mm but at 5mm is also quite distorted.

Sunlu has practically the same results up to 45° only at 300mm/s I can see the slightest curling. At 55° I wouldn’t print it faster than 100mm/s. 65° is very similar to IEMAI again.

I didn’t test the Bambu PETG because I will not use it anymore and sell the remaining sealed rolls.

Next test will be the influence of fans and layer times. I really have the feeling that not speed but time for cooling is the most critical factor for good prints.

[Alex_vG]

next test on cooling is finished. And I have again included print speed for the steep overhangs where I had the feeling, that much slower speeds could make the difference.

Small story on the last test: Actually, I misunderstood the ranges for overhang speed. the overhang percentage says, how much of a loop is hanging in the air, so the angle depends on the layer height. e.g. for 0,2mm layer height and 0,42mm line width, 50% means an overhang of 0,21mm which is roughly 45°. 100% overhang means the complete outer wall is printed over air, and the first inner wall is exactly over the outer wall one layer below. that would calculate to 63,4°. For smaller layer height, the same overhang % is a much steeper angle. e.g. with 0,1mm layer height and everything else the same, 100% equals to ~ 76°, but should print equally well. Very smart implementation indeed.
And an interesting lesson for me: I was really amazed that 63° overhang angle on 0,2mm layers means that the outer wall is not at all supported by the layer below. Yet, this is printable with reasonable results and even very good results if you print very slow as this test showed. Quite amazing in my opinion.

Back on topic:
I printed 55° and 65° overhangs, which is accidently very close to 75% and 100% in my setting. I printed at 20, 40 and 60 mm/s and each with 10%,20%,30% and 40% part fan.
I only did the test for the IEMAI PETG up to now. Maybe I do it for Sunlu tomorrow.

As expected from the last test, 55° overhangs printed flawless at any speed and any fan setting.
The 65° overhangs were perfect at 20 mm/s almost independently from the fan setting. Only at 10% there was a very slight curl at the very end, which didn’t appear at 20% fan. The faster prints were not so great throughout. More fan made them better but never good.
So I think, I will go with 20mm/s for the range 75%…100% and 0 (full speed) for the other ranges. I’m still undecided if I want to increase fan speed in the material profile from 10% to 20%. It still seems reasonably low to not decrease layerbonding. Anyway, the IEMAI PETG seems to be very indifferent about many of the printing parameters like temperature, speed, cooling,… Maybe that is due to the high speed tag?

Please note: This is the first time I spent so much time on optimising print settings for an individual filament. Well possible that many other PETG brands behave equally well if you put that much love into them
Up to now, the Sunlu seems to be just a tad behind at an even lower price point. And both put the BBL PETG to shame. I have to see if I have samples of some other brands at home and might just try them with the final settings found here.

[CheebiNeko]

Just curious, what volumetric speed did you dial in your sunlu and the IEMAI at?

I’m actually running some calibrations again this week on PLA. Was able to get through all the big parts I needed in PETG last week, so working on the cosmetic parts in PLA which I have more colors in. Seems like I need to run some more tests to tune the settings more on the PLA. Had two occasions where the nozzle ended up grinding the top surface of one of my prints.

I actually had some time also to look at my TPU last Sunday. Fun to print with, though the settings need some more looking at than the default profiles. The overhangs and small perimeters were having some issues.

Having gone through most of this recently. I’m actually liking the PETG a lot more now lol. I need to run some tests with all of the PLA/PETG settings on the other quality profiles though. I noticed a lot of the prints I had recently such as this riser which got me in this rabbit hole was set to .16. I ended up printing everything lately at the standard .2 since .16 was giving me quality issues on basic filament settings for those I tried.

Speaking of tweaking settings, any idea on the small perimeter settings? Wish the wiki had more documentation to explain this more on the sizing etc.

And speaking of PETG filament with Sunlu/BBL. Yeah I’ve also got some polymaker and hatchbox petg coming. Decided to try them out since I used their pla before also. Would be nice to have a roll or two of a brand I can know and rely on more on hand in case I want something nice in the material. The sunlu though I can’t pass up either, ordering a small bulk order as well right now to see how they arrive.

All in all loving the bambu printers so far. So much more fun to be had focusing on these kinds of details rather than the “tickering/fixing” of the older printers like ender.

As for what you mentioned on the layer heights etc on overhangs, yeah I feel like I need to look into those more as I test out the quality setting differences. Going to be another week or two of testing to see what my printer likes with the PLA/PETG I have.

[Alex_vG]

For Sunlu at 240°C i had first defects at ~21mm/s. I think i set max speed to 18, but right now it is at 20. Seems i changed and saved that accidently

I just realized that I didn’t test the IEMAI yet and just set it to 20mm/s Somehow that works fine for any of my filaments.

My last tests were inconsistent with the previous ones. On steep overhangs, the Sunlu was even a bit nicer now. Then I printed a part were i put all the settings to use, that I thought I had found and the result was terrible. Then I discovered that the Sunlu profile is set to 255 °C instead of 240°C and I have no idea when that happend. So I’m loosing trust in my tests But probably, the model was rather stupid. And a benchy at every speed 300, only outer walls 250 turned out very nice. So I’m regaining trust again.

Repeating PA and volumetric speed tests right now. Then i need a benchy with the Sunlu for some positive feelings. And then, I don’t know, probably I should print something useful instead of rounds and rounds of tests

But I fully agree that the printers are really amazing compared to what i did with my Ultimaker. I’m still mesmerized when watching it laying down a top layer at 300. And all the bells and wizzles just working.

On the short perimeters: I think I understand the setting, but I’m lazy to find out how it could improve quality.

[Warmup]

@Alex_vG

IEMAI

So how would you rate their petg performance compared to sunlu overall? 2kg black&white on amazon sounds nice, will also get them from german amazon because I’m fed up w slow bambu petg print speeds for good results…

[Alex_vG]

I think they are very close. IEMAI provides a proper technical datasheet and seems to allow for a wider range of nozzle temperature with little influence on quality.
Sunlu prints just fine at 300mm/s with 0,2mm layers and is even cheaper. You don’t get a datasheet, I haven’t measured the tensile strength, so maybe the IEMAI withstands double the force.
But for everyday printing, I will probably just go with Sunlu.

I will send you a private message, because it wasn’t easy to find the really cheap offer in germany.

[user_3180665580]

I am getting absolutely amazing results with the translucent green (brand new p1s owner), have done calibration and mainly used standard and custom profiless (slower speed) still unbelievable results. image is of a fruit fly catcher for the top of a mason jar (and it works 1 fruit fly since last night)

couldn’t fiigure out how to get the image to show, kept giving me an error about image not being allowed.

[JonRaymond]

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[CheebiNeko]

Yeah I think I started my Sunlu tests at around 20 volumetric also. But in my case I ended up dialing things down to my last post with all the settings mainly for quality. I think I have one profile around 16-18 which worked I would say like 90-95% fine with just slight line speed differences. Though in my case I was running things at 260-265. When I get a chance I think I’ll try to run things around a lower temp and see the quality comparison.

I’m just waiting for my print queue to free up of things I wanted to punch out of the printer lately. Then I’ll go through the whole quality and recheck all of the calibration with the spools. Maybe I will find something else I might stick to as well on PLA or PETG.

I’m probably going to use Sunlu for the average prints. Just need to see if there’s something else I end up liking more for a better quality result also. Would be nice to have options in stock.

Same for my PLA, I’ve been running through my hatchbox rolls yesterday for some small things. Found I still needed to tune down the outer walls a bit to get them nice. Was hoping I could run things quick and dirty with PLA still lol. I need to seriously go through these calibration tests again on PLA and find a sweet spot with these brands. Though I might stick with Bambu for a bit since I ended up picking up so many black and white refills with last months vip discount stuff they give you on their site lol.

[CheebiNeko]

Actually to recap on the overhang topic. So I’m currently waiting for more sunlu petg for some other parts I need. But been using my BL petg yesterday and today to print out some items with threads for desiccants.

Looks like I need to go back to tuning the settings again. The BL petg is giving me some slight drooping on some of the overhang threads which is driving me a little nuts to see. Works just fine, just not nice to see lol.

[Armin]

Hi,

@CheebiNeko, thank you very much for the thorough investigation.

I have the opposite situation. Initially, I used Sunlu PETG a lot with the default Generic PETG preset.

The only change I made was the max volumetric flow, it can be safely increased to 20, as well as the temperature in 265 looks better imho.
I also tried calibrating pressure advance and flow but finally left the default values, which seemed the best.

The only minor issue I had was the small random holes in the walls. I’ll try your suggestion to decrease retraction to 0.5mm.

Thereafter, I tried Bambu PETG…
I got the same weird result on Benchy and was in doubt about how it could be, provided I use the Bambu filament with the default Bambu preset on the Bambu printer

I got better but still not perfect results by increasing the temperature.
I started calibration of the pressure advance and flow and got a strange result.
It seems PA should be set to ~0.055, but I’m unsure about it since the calibrations are different for different speeds/max volumetric rates.

Just would like to clarify if you tried to calibrate PA as well?

[katze11235]

This settings are good also for PETG-CF?

[CheebiNeko]

Funny enough I had an evening which drove me nuts last month and had to recalibrate everything again. Ran into a filament clog issue which caused me to have to take apart the extruder and get the piece stuck out of the gears. There was also a problem part that I had to I think the term was cold pull out.

After that most of my original calibrations were all thrown off for some reason with the sunlu petg and sunlu pla I had been working with in bulk lately.

So to answer your question, yes I do calibrate PA as well as flow ratio whenever I throw on a new spool these days now into the AMS. I usually go and double check the settings with a quick test to make sure the roll doesn’t throw the rest of my prints off now.

After last time which I mentioned trying with some of the lower temps. I still prefer around 260-265 ish for the PETG for temp wise.

I don’t think I ever got that high on PA though. I think I was around 0.025 or 0.030 range normally. I can’t say it was perfect for speed or the optimal for the Sunlu, but it worked great result wise for the prints I wanted and didn’t have all of the printing issues I was initially trying to get rid of.