I'm very new to 3D printing, but so far I've been able to print a couple things off Thingiverse without issue. However, as I'm trying to print another part, I've run into a situation where Cura is totally confused as to what's touching the buildplate and what isn't:
All I did was use the "mirror" feature to put it in a better orientation for printing....
Any ideas what's going on here? I'm using Cura 3.4 for Linux.
Update: I tried using the rotation tool instead as suggested by Oscar, but I get the same result:
Update 2: Hmm so even when I just import the part without doing anything else, Cura is still confused:
If you want to mirror the print to get the top to the bottom, and visa versa, you just need to rotate the part using the XYZ rotation tool. Mirroring is used to make a mirror image in the X-Z or Y-Z plane, not the X-Y plane.
You might just caught a bug, you could post that of their forum.
If that does not fix it, you might have an incorrect STL model, e.g. the normals of the faces are incorrect. You could try to fix this by repairing the model through an online service like this one.