Excess stringing and protruding layer lines

So this issue just occurred recently, everything was printing fine. I tried to go print a TCG Playmat Tube using a model from Makerworld, that I’ve used before, and noticed some stringing issues during the print.

When I looked closer, I noticed on the inside of the cylinder there were rough spots poking out of the wall - like tiny spikes. Below are all the steps I’ve tried to resolve the issue so far.

It’s a P1S, with the AMS 2 Pro.

  • Tried multiple different spools of Filament, all PLA

  • Ran the spools through 3 separate drying cycles, one of which was in a separate drying box

  • Performed multiple cold-pulls to try and clear out any debris

  • Replaced the Nozzle

  • Concerned about Heat Creep I opened the front door of the unit to allow more cooler air in

  • I ran some retraction calibration prints to check if it could be a retraction issue, saw negligible stringing

  • Performed a factory reset on the unit

  • Slowed the print speed to Silent

  • Printed some ‘Calibration’ cubes and cylinders (1 wall, 0% infil) to see if there is an issue with the belts/motors moving around in X/Y Axis causing an issue.

Do you have smooth time lapse enabled? This can can cause stringing. Also try lowering your printing temperature.

The “spots” you are seeing are probably the “random” seam.

I’m not sure what smooth time lapse is?

But I did try printing the same model at 210c and 215c to see if there was any change. There was not

I am using the same roll of filament from my last successful print, and the default print settings of 220c did not produce any issues.

Smooth time lapse moves the head over to a purge tower every layer to take a picture.

No, I don’t have smooth time lapse enabled

And also to note, the ‘spots’ I mentioned, when I run my finger across them they are sticking out from the layer itself, they feel like tiny scratches.

This is either the wettest filament to ever exist or you have your Seam set to “Random”

Lots of “popular” influencers and AI like to suggest random seams to newbies - this is a trap lol, you do not want random seams if you ever care about aesthetics even one percent.

1 Like

I’ve run my filament through multiple 12hr dry cycles - at least once on the AMS 2 Pro, and a separate cycle through a Sunlu drying box.

My seams are set to ‘Aligned’, I use the default 0.20 ‘Standard’ profile. I do have a separate part to the print that uses a different color filament, so the only change under the Prime Tower is the infill gap and rib wall.

I find random seam to be less strong as well. It is probably better theoretically, but I prefer to know where the weak point is and build around that.

If thats the case I would strongly consider drying, although you said you’ve done so twice now. I’m unsure. Can you slice the model, and in the preview tab of the slicer, take some similar screenshots to the real life ones shown? Or share the 3mf for further analysis. If those arent random seam, the wisps indicate a travel right before them, and getting deposited there. You can enable view of travel in the slicer preview to confirm further. As Jon mentioned, Timelapse [of any variety IMO] is a possible culprit

I’ve included screenshots, including showing the travel lines, the screenshots are about where the print is in the picture. I have also included a copy of the 3mf file

Mat_tube_6cm(5).gcode.3mf (9.9 MB)

Aha, the physical pictures didnt show that outside knurling, which creates little islands of loops inside each. So those travels depositing the wisps are from the inner wall knurl segments, not something like timelapse’s travels.

So, the issue remains something more like oozing/string, which… often points back to wet :slight_smile: You can also sometimes reduce ooze by reducing nozzle temp if you’re right at the edge, try -10C and -5 max volumetric flow?

To save some sanity, do you have any other rolls of filament to do a one-off trial of?

I can try, as part of my troubleshooting I did try 2 separate spools of filament, both from different brands.

One is PLA, the other is PLA+, and they both showed the same results.

And I tried 2 test prints, one with the nozzle at 210C, and another at 215C.

My concern is that I had been using at least one of these spools of filaments before for the same model just a week ago, with the same settings I normally use. It just started printing like the pictures.

Here’s another example of the same print, but on the print bed.

With the same filament, I printed a 5mm x 5mm cube to test with 1 wall 0% infill. And it looks almost perfect.

I’m guessing the cube doesnt have any large travels thru open air :slight_smile:

Lets step back for a minute, did you do pressure advance/k-factor/flow dynamics on this filament? What was the value? That cube has an unattached rounded edge near a corner, which is often pressure advance not tuned for very high speed. Bad PA can cause strings too.

I did perform a manual calibration, which showed a preferred k-factor of 0.02, which is what it was already set to.

Welp, thats all my ideas. I dunno! Good luck! Maybe try printing something you didnt slice, like a gcode benchy on the SD card, to remove the current slicers settings completely from the equation, just machine and filament.

I did try that as well unfortunately already (results below) but I appreciate your help in trying to resolve this.

Can you post your filament settings? In particular, but not only, the advanced settings?

You may want to enable “avoid crossing walls” and give a distance of say 100mm in the Quality settings.
You can also check for “z-hop” (disable if enabled) and and “wipe on retract” (enable both checkmarks) in the advanced filament settings.

:four_leaf_clover: & :crossed_fingers:

Thank you for the suggestions, I think I copied all the settings you wanted to see. I enabled ‘wipe on retract’ but left the checkbox to the right of it unchecked.

I did also enabled the ‘avoid crossing walls’ like you suggested.

1 Like