Hello!
I am new to the forum. My A1 is about 14 months old. 2200 printing hours. The hotend was replaced less than 100 printing hours ago.
Hotend 0.4 hardened steel.
Filament: Elegoo PLA.
Flow calibration and bed leveling is on when I print.
Layer height 0.08 High Quality.
Infill 100%, Rectilinear.
I am having a problem printing a part. The internal layer surfaces are irregular and have many rough spots. These rough areas become more pronounced as the print progresses. The hotend also seems to create some friction against the surface of the part, judging by the noise it produces. The issue appears, or at least becomes more noticeable, when the printer starts performing a color change. I also tried swapping the colors to check if the problem was caused by one of the filaments, but the result was the same. The first photo shows three print attempts, all of which I manually stopped. When I reduce the infill setting from 100% to 15%, the print proceeds smoothly. I am attaching a photo of the part being printed with 15% infill, as well as a photo of the tower. I am also attaching two screenshots of the settings I used to print this part.
100% infill:
15% infill:
Settings:
With 100perc infill your flow rate must be spot on. Any overage gets squeezed out. I’d run that test. Note that flow “dynamics” and flow “rate” are two different metrics - the nozzle sensors attempt to do dynamics for you, but rate is up to your test
Would also remove “reduce infill retraction" setting, I can see the traveled ooze line in your top surface.
It’s also possible you are running too fast, but I think it’s flow rate or moisture related. Moisture makes your flow rate wild and unpredictable but I think it’s just too high.
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Now that you mention it, I realize that when I changed the hotend, I tested the flow dynamics and not the flow rate. To be fair, this is the first time I’ve noticed or encountered this problem, even though about 80 percent of my prints have always been done with 100 percent infill. I’ll run some tests and report back here. Thank you very much.
Hi, welcome to the forum.
To me the scraping issue looks like the solid fill part is warping, coming up from the plate as it is being printed, so subsequent layers start to dig into the existing ones. The nozzle is being forced through the existing hardened plastic.
Part warping is very much dependent on density, so your 15% infill object isn’t going to warp nearly as much as the 100% infill version. Though it looks like it still warps a bit, perhaps, with a visible layer line at the bottom of the rocket. But after that it stays stable.
During a color change the print is sitting for a bit while the filament is swapped, cooling, which is when warpage will happen most. So it may seems like the color swap is causing it, but that’s probably a symptom.
Shrinkage/warpage also gets more pronounced as the difference between ambient and printing temperature rises (especially the bed temperature). Not sure about Georgia weather, but if you’re affected by the recent cold snap, that could also exacerbate the problem. I know it has in my case (upstate NY), even with just a few degrees of change in avg. room temps.
If I’m right and you still want solid infill, mouse ears or a brim may help. Cutting channels inside the model to break up the fill can help, and other anti-warp techniques.
I’m not sure about the stringing/blobbing on the tower or whatever is going on there… possibly a different issue. The sparser infill part looks a little stringy also, so maybe a calibration or temperature issue, as suggested already.
HTH,
-Max
Thank you, Max. I’ll try to learn how to use anti-warp techniques.
Flow rate calibration was indeed needed. In fact, it was so bad that I couldn’t even complete it. I attempted it twice and had to stop both times.
Then I tried running a flow dynamics calibration first and doing the flow rate calibration again afterward. This time it worked.
The first picture shows the results from the first two attempts.
The second picture shows the result of the third attempt, made after the flow dynamics calibration.
The third picture shows the result of the first test I ran with 100% infill, printing one small section of the part. It’s definitely improved, but the tower still shows some issues.
First of all, my apologies if I’m asking for support on something that, after more than 2,000 hours of printing, I should probably already know. As I mentioned before, this is the first time I’ve run into these kinds of problems. Flow control, speed, and temperature are things I’ve never had to adjust, so when it comes to debugging, I’m really an amateur.
Now for an update.
Today I tried to print a different part.
Initially, printing in black showed some improvement. The tower was still exhibiting issues, but the part itself was acceptable.
The problem started after the color change to blue.
I then performed a flow rate calibration for the blue filament. I decided to be a bit more aggressive by selecting the parts indicated in the pictures. The result suggested a flow ratio of 0.7762.
I printed the part again (it is currently printing), using that profile for both the blue and the black filament. The tower is still showing some issues; however, the part itself, while not perfect, is getting close to my level of acceptability. Definitely an improvement.
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