[jstanley]

I've never had any problem with FreeCAD-generated STL files, and I've made hundreds, and I've been using it since 2017.

Can you share a FreeCAD project & the generated broken STL file and I'll see if I can reproduce the problem?

[JohnFen]

It is possible (and pretty easy) to use FreeCAD in a way that it will generate faulty STL files. It all depends on how you did the modelling in FreeCAD. I think it's an example of how there are many ways to accomplish something in it, but some of those ways are wrong -- and you won't know it at the time.

What I do when I get a faulty STL out of it is to use other programs to fix the STL. That gets me there. And many slicers these days (especially Prusa) are getting much better at doing this themselves, making it less necessary to do it as a separate step.