Can't print this conical part without defects

Bambu Lab P Series Troubleshooting
1

I tried to print this lid part from MakerWorld multiple times with different filaments, but it will always show the same defects:

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I tried a similar part, but same issue:

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Any idea?

2

Do a pressure advance calibration, and make sure your filament is able to feed into the printer very freely.

Also, please post your 3mf file here and we can take a look, it also could be related to bad scarf seam settings, but do the first two things first.

3

I already linked the file in my post:

4

Is this a PETG print? The defect is quite common when printing with moist PETG and/or too fast.

:four_leaf_clover: & :crossed_fingers:

5

Both PLA and PETG, doesn’t make a difference.

6

Try adaptive layerhight
..25

7

What exactly do you mean by that? Where can I set “Adaptive Layerheight” to “25”?

8

Have you tried using the ‘nearest’ option on the seam rather than aligned? It won’t necessarily make the blemishes go away but will spread them around so that they are not so noticeable.

9

In that case it looks like that, is that even normal?

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10

To be honest, these look like classic cases of moist filament and a lack of calibration.

While a P2 can take care of flow dynamics calibration, a P1 can not and calibration needs to be done manually.

Filament Drying Recommendations | Bambu Lab Wiki
Flow Dynamics Calibration | Bambu Lab Wiki
Flow Rate Calibration | Bambu Lab Wiki

If the issue still exists, we can look at seam settings, speeds, retract/wipe,
 But filament drying and calibration need to be done beforehand.

:four_leaf_clover: & :crossed_fingers:

11

I can try to dry the filament, but I am 90% sure that this isn’t the reason. The PLA filaments I use never at all had shown such prominent defects (see first post) due to moist. I’m doing 3D printing since 5 years and never had to dry PLA or use any calibrations—other filaments are a different story of course.

12

Give it a go. I have to dry all of my PETG and got into the habbit with PLA as well.

The defects visible in the pics are typical of moisture (all of them due to the strong effect of moisture on thermal properties), a lack of flow dynamics calibration (faulty pressure advance showing at the back and random seams) and moisture/too fast a printing speed (inner circle outer line pull-in).

:crossed_fingers: & :four_leaf_clover:

13

Hi!

I have some news. Drying the filament over night didn’t change anything as expected:

0.16 mm High Quality (as configured in the file here):

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I now tried the 0.20 mm Standard preset. In that case, the issue is way less prominent but it is still not perfect:

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14

Well, using the red filament, presumably dried, seems to have eliminated the outer wall pull-out.

But it is very difficult to actually help as you are linking a model page with multiple profiles rather than providing details of your filament used, settings, drying times and temps and calibration results.
The defects are very typical of PETG, yet you state it does not make a difference in your case.

As for the seam defect, it’ll never be perfect. But Flow Dynamics/Pressure Advance determines the lag between extruder action and reaction at the nozzle tip. It counters a bad timing of the start/stop of extrusion and needs to be set on (dry) filament.

If the red part was done in PETG (HF or Basic? Or something else entirely?), try flow dynamics calibration and a speed, maybe even acceleration reduction.

Since you do not post about your actual materials and their settings, drying time & temp, calibration results or process settings (seam type and settings, speed limitations), there’s unfortunately not much more guidance I can give.

:crossed_fingers: & :four_leaf_clover:

15

Hi :slight_smile:

Sorry that I didn’t provide enough information for you.

The red filament is ELEGOO High Speed PLA+. The last photo, where the defect is way less prominent, is just the “0.20 mm Standard” preset from Bambu Studio with a 0.4 mm nozzle, I didn’t interfere with that. The preset is “Generic PLA” which I also didn’t change.

I didn’t yet apply any calibrations.

The photos where the defect is very prominent (here) is where I used the default print profile:

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But I think we can ignore this since the default “0.20 mm Standard” improved the print.

So now the question would be how I could improve the seam using this profile :slight_smile:

16

That does actually help a lot. :+1: :smiley:

But it also shows the limits of my experience. While I print a lot and have seen many issues, I do not use Elegoo and am not familiar with any peculiarities.

So there are a couple of options now:

  1. Look at published print profiles. I did not find an official print profile for Elegoo PLA+ from the manufacturer quickly. I did stumble across two user made ones though:

However, neither of these mention seam settings. So I am concerned that these may not actually be able to remove the seam defect. Nevertheless, you should be able to compare typical Pressure Advance/Flow Dynamics settings.
It’ll still not be as good as calibrating yourself, but probably better than defaults.

  1. I remember these type of defects in areas of high acceleration from the release of the original Bambu PETG. If I recall correctly, rapid acceleration caused thinner lines than at constant speed. So you could try to lower wall accelerations (a lot) at the cost of print speed. With the original PETG Basic, I lowered accelerations down to 1/4 of the defaults.

  2. Ensure the “Smooth speed discontinuity area” is enabled. This is likely the case but the parameter can be increased from the default 150 to 200.

  3. Have you looked at “scarf seams” yet? I find them to be very helpful. Still noticeable but in my experience much better. However, there are more parameters to optimize if neccessary.

Personally, I’d use scarf seam with reduced accelerations. But it is different when looking at pics on a screen than holding the piece in hand and being able to observe the defect in person. Just keep in mind that you’ll not be able to eliminate the seam. And that last pic already looks pretty good.

I am just a bit puzzled as to why/how a higer layer height alone would make such a drastic difference. Maybe a look at max flow and speed previews for 0.16 and 0.2 could shed some light? If speed/acceleration is the problem but the print is max flow driven, a lower layer height leads to too high an acceleration?
In this case, a higher layer height would slow printing and achieving better seams at lower layer heights would require lower speeds/accels. But to be honest, I am speculating at this point. And there could be further interactions between line width versus layer height triggering different fan settings
 That should show in the preview though


:crossed_fingers: & :four_leaf_clover: