Help needed with software  

title here

I've found over the years that some, make that many, of the .stl files on those 'usual suspect' sites can be incredibly wonky.

The first thing I will try will be to slice the model with Cura instead of PrusaSlicer.  Cura seems to be more able to 'take a joke' WRT corrupt .sti files than do any of the Slic3r variants.

The next thing I try with wonky .stl files is to import them into FreeCAD, convert mesh to shape, refine shape, convert to solid, and re-export to .stl.

You can also try any of several mesh repair tools (meshlab, etc.) and one of them may or may not give you a printable file.

Thin walls

Usually this is caused by model components (such as walls) too small to be printed at your current extrusion width. You may try to activate the setting "Detect thin walls", but this may cause other issues. Or try to reorient the model on the bed, this sometimes helps. It's usually models for which the designer did not really consider the limitations of FDM printing (aka student projects).

Sometimes a smaller nozzle may work—but will of course significantly increase print time.

And of course @jsw is right, this may also well be just good old errors in the STL.

You can try to fix STLs with problems (and if you download ANYTHING from Thingiverse, Cults, etc, there's a fair chance it has problems) by running it through netfabb https://service.netfabb.com/login.php, which usually does a good job, unless it's a hopeless case. Even though PS uses Netfabb, the standalone Netfabb app or their web service seems to be able to repair models, PS can't.

Some modeling software, such as Blender, has built-in repair functions as well.

Just a heads up but the stand alone netfabb isnt available any more.  They rolled it into Fusion 360.

Thanks to all for the rapid response

Who knew it would be so difficult?  Are there any "known good" download sites?

Confirmed that https://service.netfabb.com/login.php is kaput.  Will try Cura.

Stay tuned for more exciting adventures in 3D printing... 🤒 

The drama continues...Cura can't cure it

Downloaded Cura, added "mesh tools" opened 7.stl and got this:

The loaded error infested file of a picture frame is in the upper right corner.

Are there any "known good" download sites?

Standalone Netfabb

@neophyl

Thanks for the heads-up. I'm a Fusion user so I saw it got rolled into Fusion but I didn't realize they shut fown their website.

However, the old standalone version is still available from https://github.com/3DprintFIT/netfabb-basic-download.

And honestly, I almost always used the standalone version rather than the website. It has a stupid flash you have to wait for, but otherwise it works.

After what, 20 years, the Mac M1 made me switch back from Windows to MacOS, and I just realized that the Mac version available from that website won't work on the M1. Oh, well, so it'll be Fusion going forward...

Standalone Netfabb

@fuchsr

  https://github.com/3DprintFIT/netfabb-basic-download ... gives 404 error.

@butchalline

The link from @fuchsr gives 404 because there is a point (.) at the end of the sentence, which is included in the link
However, the link you wrote in your reply works just fine 👍