We recently purchased the X1E for our company. The PLA prints came out great—impressive quality and very fast.
Since our prints need to withstand disinfectants, we wanted to start printing with PETG. I ordered the PETG HF in white directly from Bambu, but the first prints were really disappointing. To test further, I tried printing a simple cube.
After reading some tips here and online, I increased the print temperature to 270°C, but it didn’t improve.
The filament was dried on two consecutive days for 12 hours at 65°C.
I used the 0.20 profile and made some adjustments I intended to do anyway (Arachne, outer walls first, infill gyroid), but these changes didn’t affect the print quality and the defects are still the same.
Using the textured PEI Plate but this should not change the wall quality I guess. First and last layer look really good.
Could you please confirm if the Z seam position is set to aligned?
If the position is set to Random, the issue you shared in the picture might be linked to this.
When it comes to drying, always make sure the drier has a small opening where the moisture can escape. If the drier is completely closed, the moisture will remain trapped in the drier, and in the filament.
Filament drying is really hampered by ambient humidity. Think of how sweat doesn’t evaporate on humid days but evaporates easy on dry days. If you already have issues with filament moisture, drying tends to be problematic too.
There’s a thread here on filament storage. You can put a filament spool in a poly cereal box with a hygrometer, seal it, and let it sit a few hours to overnight (until it stops changing) and you’ll get a humidity number. I bet it will be fairly high. So far the two PETG HF spools I’ve measured like this have come up at 40 and 42% relative humidity fresh from shipping bags and before drying. After drying the hygrometers settle to 10% which is the lowest my hygrometers read. Actual poly box humidity is somewhere between 0 and 10%.
After drying to low poly box humidity my PETG HF prints great. I finally finished the PETG HF clips I’ve been printing but they printed with no issues.
Printing before drying just to see… (minor issues)
Thanks for posting a clear picture, this helps a lot.
My first reaction here is that it looks like this is more of a calibration issue. My experience with the default Bambu factory profiles are mixed and I’ve found that one can benefit from manually calibrating the filament. In this case, I’m seeing flow issues in your model. I would recommend three calibrations steps.
Flow rate
Max flow rate
Temperature Tower.
I would suggest you download Orca Slicer since that has baked-on calibration tools that Bambu Studio does not. Since it is a clone of Bambu Studio there is no downside to having both tools on your machine but you would be forgiven if they look identical out of the box.
Here’s the tutorial.
If you want to see a quick YouTube video that I usually recommend it’s from this guy at ButterPocket Prints. There are other great calibration videos but his really does a good job in under 10 minutes.
Here’s a more advance version(part 2) from the same guy but first stick with the 9 minute part 1 video.
One think noteworthy. Placing a spool in a dryer does not guarantee that it was sufficiently dried. One must weigh the filament before and after to ensure that filament indeed had moisture. You’ll only know for sure by weight. Don’t be surprised if you removed 3g of moisture only to find out if there was much more. A cheap kitchen scale is all that’s needed for this task. https://www.amazon.com/s?k=kitchen+scale
You might ask, how can you be certain that all the moisture has been removed? When the spool stops shedding weight. That’s why it’s so important to get before and after. In the case of PETG HF, I was able to remove 5g of moisture right out of the factory box before I even put it into service. But I did do a test print just to see how it would perform and I got similar nubs to the one’s you’re showing in your photo.
Now that the source of the problem is identified, you can simply do the Flow Dynamics and Flow Rate Calibrations in Bambu Studio, most of which is automated.
I also recommend ensuring you are using the default filament profile settings, as they were fine tuned for best results. Considering that you have changed the location of the Z seam, if you changed other settings in the default profile, it could impact the print results.
Try using the default settings first as a test, before trying any other calibrations or tests.
But @Olias, how do you determine when a small weight change is because the spool is already dry vs trying to dry in high humidity where you can also see a small weight change but the spool is still “wet”?
I know you have the poly boxes and hygrometers. Have you tried just putting spools in boxes with hygrometers to see what kind of numbers you see for new undried filament and dry filament?
To answer your first question, which surprised me because I believe you already know, but since you asked…
To determine if a weight change in filament indicates a reduction in moisture, you would need to weigh the filament before and after drying. A decrease in weight suggests that moisture has been removed. The principle behind this is that the filament dryer uses heat to evaporate the water absorbed by the filament, which then escapes into the air, resulting in a reduction in the filament’s overall weight.
I believe your question may be related to small differences. In the world of 3D filament, I have yet to experience a difference in print quality when the moisture content falls below 1% by weight. So if we’re using a scale with only 0.1g resolution on a 1Kg spool, you can see how the measurement is “good enough” for our purposes. In other words, “a wooden ruler will do the job as well as an expensive micrometer when measuring larger measures.”
I am good with that stuff. Weight change can definitely be used to quantify water weight loss in filament. My question was when the weight change is small, how does weighing tell the difference between a “dry” starting weight and drying on a humid day when drying can be terminated prematurely when the weight doesn’t change much.
Small differences is exactly what I’m referring to. The thing is weight alone cannot tell you why the weight stopped dropping during a dry. You need a humidity measurement of some kind to nail down which end of that scenario you are on. If it’s humid in the drying chamber then the spool will not be as dry as if the humidity ends up low in the drying chamber but the humidity is key to knowing why a weight change is small.
Have you ever tried just putting a spool of filament in a poly box with a hygrometer but without desiccant? Easy test and trivial to do and it tells you how wet your filament is. Like I said before, factory fresh PETG HF clocks in at 40-42% RH (which I know is not a direct measure of filament moisture - it’s indirect) and 10% indicated (actually somewhere between 0 and 10% RH) after drying. Before I dried the PETG HF I had minor moisture issues but after drying the prints are perfect so it does seem to be a good companion to weight measurement to either explain why you see some drying result or not.
Well, the arch is where you could add a manually painted support, using PLA as an interface material, 0mm z-distance.
Regarding ironing, I do not use that with PETG as it tends to stick to the nozzle. It may be worth a try, but don’t expect too much.
