What is causing this tearing pattern every so often?

I like the look of it, but I only use it when I think it will fit the model.
The blends are a weaker filament, so no less than 3 walls…and it still might break if you drop it.
The only issue I ever had with it…I find that supports only work on build plate only…they won’t stick on top of itself.

Iron Man & Batman are CF-PLA

Rat Bowl is CF-PETG

As you can see I’ve never tried the colored blends as black was the only color for years.

There are YT videos where users say that the CF flake off after awhile & might cause health problems..or you can get it stuck in your finger like a splinter.

Thanks @Lion It really does print nice! I love the matte look of the Rat Bowl figure, look is exactly what I’m looking for, like the model as well :slight_smile: Thank you for sharing the photos, helps me decide which filament type to focus on.

Interesting point about dropping, thought it was one of the stronger functional part filaments, probably my misconception, and Interesting about the supports. Thanks for the important notes, appreciated.

To be honest I had not even noticed the various colors, until I was digging into the CF filament types IMHO some of them look pretty good, really like the Flashforge PETG-CF colors.

Cheers,
-Mike

Took a photo of the label for the Sunlu high speed matte, for heat settings.

Looking at that, may be worth lowering the nozzle temp a few degrees & seeing if owt changes.

Thanks to everyone for providing the ideas, they helps lead me to a area I never expected!

I’m still learning about 3D printing, sometimes multiple times a session as I print things. This was a fun one to explore and understand, at least I hope I understood :melting_face:, just the interaction between the knobs was really fascinating to figure out. This may not be the correct way to fixing the issue, but it’s what worked for me in the end.

I do believe the issue could be handled better, just don’t have the depth of knowledge a lot of folks here do. I’m open to alternate solutions, as I’m pretty sure my solution will not scale well.

This comment from @HandyDoodads helped start me down the path.

Cheers, :tumbler_glass:
-Mike

P.S. Those camera photos :grimacing: IKR …

Filament: Jayo PETG HS - 12 mm3/s (150 mm/s) Amazon Link
Printer: Sovol Zero:
(Made for heroes too :+1:)
Slicer: OrcaSlicer 2.3.1, Sovol Stock Settings Used.
**
Model Description:** Single part two offset top layers. Protective end cap.
Top layer: 1 ~2mm above fist layer. Large square area with beveled corners.
Top layer: 2 ~6mm above first layer. Rectangular shape.
Model dimensions: X:~60mm,Y:~49mm,Z:~8mm
Model orientation for print: Lower left corner of the model X0,Y0,Z0 laying flat.

Print settings causing the issue:
Strength → Infill:
Sparse Infill=5%
Sparse Infill Pattern=Rectilinear
Sparse Infill Direction=45 Degree

Speed → Other layers speed:
Top Surface=150 mm3/s

TL;DNR / Updated these two settings:
Strength → Infill:

*Sparse Infill=15%

Speed → Other layers speed:
*Top Surface=50 mm3/s

Issue:
Having two different top layers and the above combination of settings was causing the issue. The lower top layer was caused simply by speed. The easiest fix was to reduce the Top surface layer speed. The second Top layer issue needed both speed and infill settings changed. The Sparse infill direction contributed to the weird consistent tearing pattern and were unchanged.

Lower Top Layer:
The lower of the two top layers continued to have issues until the speed was reduced. The lower area being ~2mm had a single sparse infill followed by internal bridging layer, covered with solid layers until the top surface layer. This resulted in the 5% pattern still still causing slight deformation in the pattern allowing for a loose bond between the layers of the rectilinear pattern.

Higher Top Layer:
While printing the Higher top layer had had it’s speed reduced the tearing could still be seen due to the height of the sparse infill pattern resulting in a more prominent deformation of the infill pattern resulting in the tearing still occurring. This was more easily seen while watching the print. As the space infill layers were being placed, you could easily see the height and gap were going to be a problem. Once the internal bridge went down you could see a slight sag, followed by the internal solid infill layers. Once you saw the surface layer placed on top of the already deformed layers due to the large infill layer gap, the tearing was instant and between the gap edges. By reducing the speed, this allowed time for the the top surface layer to lay more easily into the last layers. The model is only 6mm, I’m sure if I made the model taller, I’d actually see some serious sagging indentations show up.

Extra Note:
I want to look into the Speed → Acceleration → Top Surface = 5000 mm3/s speed. I feel like I might be able to move the lowered Top Surface = 50 speed up a bit by reducing the Top Surface Acceleration speed.
Also want to investigate the sparse infill part of the puzzle. Why, when I bumped the sparse infill up to 15% and speed back to 150, the tearing was still seen, but at a much smaller scale.

The part came out really nice after making those two changes.

Tried to increase speed and resulted in failed print but at much smaller scale.

Trying to validate speed change only fight with second top layer.
Failed 5% Sparse infill, 50, 55, 65, 100, 150 Top surface speed tests. Green box passes randomly as seen by the next one to the left that I tried with speed of 50. Several more in the red passed lower top layer, but the upper top layer was always problematic until changing to infill of 15% and slowing top surface speed down to 50 mm3/s.

Your getting there :+1:

Apologies @HandyDoodads It was very overly long Sunday of testing :grimacing: and I missed quoting your comment started me down the path ultimately leading to the resolution. I’ve corrected my post to include your comment.:man_facepalming: thank you.

Cheers,
-Mike

Hi @Matt I notice you have the mint green! I have been eyeing that color, how do you like it?

In case you were interested, here is the sticker from the Jayo High Speed Matte Black. I just used what had worked for other PETG bed temps in the past.

I think that Mint Green is a lovely colour. I’d definitely recommend giving it a whirl. This is something I printed with it the other day.

Thanks for the picture @Matt it is a nice mint green color indeed. Next time this 2kg / 0.25kg 8 roll sampler pack on Amazon is on sale I think I’ll try it out, I have been eyeing some of the other colors as well!

Cheers,
-Mike

You’re welcome. I do think you’ll like it. Pleasing to the eye, it is.

@Lion Now that I have things somewhat tuned, I did a quick test and agree, your CF-PETG filament Rat Bowl version does have a really good look.

Here is my 70mm tall Rat Bowl version using the Jayo HS Matte PETG filament. Personally I think it looks more like the CF-PLA model you posted.

Thanks for sharing helped a lot for comparison.

Cheers,
-Mike

Jayo HS Matte PETG Rat Bowl Front

Jayo HS Matte PETG Rat Bowl Right Side

I looks good. I’ve printed a few in normal grey PLA also. People think they’re cute & when they it…they want it :grin:
Whenever you do print in the CF Blends, it also has a different feel to the touch.