Question Odd artifacts

[stolowma 1]

I've noticed these odd square structures in a few models. They pop up randomly usually in or near corners and are only in one or two layers then disappear. I don't think they affect the printing quality but I'm just curious.

[ahoeben 1,965]

It looks like they may be part of the model. Can you save a project (File -> Save project...) so we can check out both the model and your settings?

[stolowma 1]

10 hours ago, ahoeben said:

It looks like they may be part of the model. Can you save a project (File -> Save project...) so we can check out both the model and your settings?

Project attached. It's a Thingiverse STL so I don't have the original model. I found a few other anomalies, extra interior walls that aren't attached to each other. I've tried running it through MeshLab following a tutorial and while it found and fixed several problems it still shows up the same in Cura.  Strange thing is I tried slicing it with PursaSlicer and none of those show up and there's no message of it not being watertight.

Fan_Mount_Bottom_v2.3mf

[Torgeir 248]

In the previous Cura versions, Cura install a "small rounded sector" just where the small squares is located.

 

Thanks

Torgeir

[GregValiant 1,321]

-> Analysed your file:
--> 0 Naked edges (?)
--> 0 Planar holes (?)
--> 0 Non-planar holes (?)
--> 263 Non-manifold edges (?)
--> 384 Inverted faces (?)
--> 0 Degenerate faces (?)
--> 259 Duplicate faces (?)
--> 0 Disjoint shells (?)

-> Repairing: 100.00%

----- Repair completed in 12051ms ------
-> Vertex count changed from 8676 to 9147 (+471)
-> Triangle count changed from 17636 to 18314 (+678)
-> Problem.stl available for download. Click the button below to download

 

I used https://formware.co/OnlineStlRepair for the repair.  Here is an STL.

 

It looks good to me (but so did my first wife).

 

Problem_fixed.stl

[stolowma 1]

🤣🤣

 

Well it seems to have printed fine but I wasn't able to hover over it to see if the weird stuff actually printed or not.

[ahoeben 1,965]

You can also diagnose this in Cura, using X Ray view:

 

The X Ray view (left) shows that the model has an internal subdivision right where you are getting the extra walls. The generation of the extra walls is probably caused by a rounding issue of coordinates in the model.

 

Interestingly the model check in the MeshTools plugin does catch the issue with the model, though Cura itself does not.