I’ll preface this by saying I’m new to 3D printing and the X1C is my first.
However with reading around the topics it seems as though I am getting… unexpectedly good results when running calibration via OrcaSlicer…
The purpose for this post is to see if I have missed something stupid, or to confirm whether people are indeed getting these results from the X1C.
I am using eSun PETG filament with a 0.6mm nozzle on PEI. Temp is 230ºC (after some poor adhesion at 220ºC, temp tower starts getting iffy quality around 235-240ºC). Flow ratio is ~0.9 post-calibration. Aux fan is off. Arachne is on. Layer height 0.3mm first, 0.18mm thereafter.
The tests in question:
volumetric speed
VFA
Volumetric speed, as I understand it, usually maxes out around 15-25mm³/s for PETG.
I upped the calibration speed to 40mm³ after having no issues with the default settings and still produced a print of high quality (apart from a couple of blebs right at the final section of the top layer).
The preview window within OrcaSlicer confirmed the flow rate to be increasing to that level and first layer calibration was disabled; I don’t know how I can confirm the printer was following these instructions beyond that?
For VFA, as you know this test is performed by increasing the speed. Again the default seemed to print ok - perhaps even a bit better at higher speeds - up to 200mm/s. Now PETG it seems is normally recommended to be printed at about 60mm/s perhaps up to 100mm/s. So I thought, let’s push it further and set a calibration test between 200-400mm/s. As you can see there are somewhat different results on the different walls of the model, in general with issues starting between 280mm/s-320mm/s but on one wall (pictures) significantly worse but still only starting after around 230-240mm/s.
Am I interpreting the models correctly? If so, why am I achieving speeds over double the upper recommended limit without significant issue?
Similarly for volumetric flow, is 40+mm³ what people are getting on these machines with PETG?
The main thing with petg is the layer adhesion and you end up with weak parts. This is why you see the filament makers giving recommendations on speed and petg is not a speed friendly filament if you want strong functional parts.
So ya it will flow that’s not the problem it layer bonding you want to keep in check for strong parts
The 0.6mm nozzle really helps here too vs the standard 0.4mm nozzle that most use. I’ve gotten similar results with the PETG/0.6 nozzle combo. I use Overture PETG at 160ºC and can achieve good layer adhesion up to about 250mm/s. That said, I rarely print that fast and typically stay around 150mm or less.
That seems really fast for PETG, especially at the lower temp range (230-240). I print PETG around 250-260C at 18 mm³/s (12-16 is likely the real safe sweet spot for strength and speed). That seems to be the flow limit on my PETG (Xvico). I’ve done some at 20 mm³/s, but experienced issues with that on the calibration flow speed test. I use a .4 hardened nozzle so the temps and flow numbers aren’t a direct 1:1 comparison.
However the flow numbers you set in the calibration test can be vastly different than what you get in the actual test if it is not set up correctly. There’s a setting labeled “Slow down for better layer cooling” in the cooling tab of the filament profile and that will almost negate your flow number fully.
You can check the flow rate and speeds of the slice by slicing it and changing the drop down selection from “Line Type” to “Flow” or “Speed” if you want to see what is really occurring in the slice.
I’ll do some more testing for strength at a couple of speeds and see how I go then.
Yes just4memike, the preview window in OrcaSlicer confirmed the flow rate/speed as being that high.
How does the higher temperature affect quality for you? As you can see, the finish quality really suffers by 250ºC for me, as well as a bit of stringing and the obvious bridging issues which can be mitigated with supports.
The allen key is pointing to 250ºC, the writing is hard to read. Down is hotter in increments of 5ºC.
WOW, that is terrible. I use two types of PETG, Polymaker and Xvico. Both take 255C with absolutely no problem. I do dry my filaments religiously though. That may be the issue you have. Higher temps would, IMO, exaggerate the steaming moisture and cause weird surface quality and poor strength. The only weird thing there is I would still expect to see the signs of moisture at lower temps too, but I don’t really notice it in that pic.
Note, Bambu’s generic profiles have a max of 270C to cope with the speeds and flows. When I ramp up the speeds and flow rates, I do pump it up to the 270C range and start to see the stringing. But the quality is still great. It gets a little more matte as well, which I like.
Could be, I have a dryer on order but will be a couple of weeks yet. They’re fresh out of the bag filaments but that doesn’t mean they wouldn’t benefit from a bit of drying out all the same.
I’ve been tempted, but a) I don’t know what my oven’s temperature control is like, and b) my actual print quality is good - here’s a sample benchy. So I’m not in a rush to fix something that doesn’t need addressing immediately and might result in me accidentally melting all my filament!
Yeah, I’ve always been hesitant to use a oven, but I have noticed just about all of my filaments come out of the sealed bags and stabilize at about 30-40% humidity in my dryer. I tend to dry them down to under 20%, so that’s a pretty big delta out of the sealed bag. For PLA, you can generally get away with that without too much trouble just printing it out of the bag, but PETGs and Nylons are more sensitive and quickly gain moisture out of the bag.
If you have an X1, you can actually use the printer as a dryer, and I’d trust that more than an oven. It basically needs a cover and uses the bed to heat the filament to 65C (PETG) and has a timer on it. I believe there is a option on the touchscreen. Procedure and 3mf file for drying filament with the X1C printer | Bambu Lab Wiki
Polymaker says their PETG that is one day out of a perfectly 0% bag, in a humid environment, will be at about 50% of their maximum moisture absorption. Just one day. Note, that doesn’t mean 50% humidity in the dryer, but 50% of the maximum water absorbed. So, just know it sucks up moisture very quickly.
Big improvement after drying with the X1C. Does take away from precious printing time though
Have upped to 245ºC for general purpose and the proper dryer can’t get here soon enough…
Cheers all
I’m newbie so I cannot create new topic. I finish demo bambu PLA reel and try to play with PET-G. I read and change some basic settings, detail look’s not so bad, but printing take much time. I see that at my "tower’ filamnet flow rate goes down much- from 16 to 0,2mm3/s. I’m not sure that is necessary and I wonder to know which settings define this speed.
Sorry, I am not allowed to attach pictures… antispam in this forum is set too strong ;/
You live in the belief that if something goes wrong with printing, you will go to the forum and search or simply ask. But no… it’s not that simple.
Even if I can add only one image- is much easy to understand what is going on for people who can help. Intead this I need to write some “no matter” post
O, finally, is ulocked. So, any idea which setting made my upper layer (almost all layer) with low flowrate?
Take a look at the “cooling” settings within the filament settings. If the layer time is short, the slicer will give the filament more time to cooling and reduce the speed.
Hmm, I set cooling for 100%, but ok… at right is layer time. Something happens when I set 3s instead 12. In your opinion, I can try to print it with layer time at 2…3s, or it’s unsenseles
Deselect “Slow printing down for better layer cooling”. At the end you had to play with these options to find the best settings for the model and filament.
You can also try to clone your model. Print 4 or more copies at the same time brings up the layer time and gives a higher speed. Sometimes the print quality of such small models is better if you print multiple parts at once.
