Create thicker shells in some areas
Is it possible to create thicker shells in certain areas?
I have room for a nut and around this I need stronger walls/shells so that the nut does not spin when tightening.
RE: Create thicker shells in some areas
Use a modifier and set the perimeters to be higher. Be aware that it will add extra perimeters also around the outside of the modifier too, due to the way they work but it will strengthen up that area. If you dot want those extra visible on the surface then you will need to size them to be just below.
Some basics on them is available here https://help.prusa3d.com/en/article/modifiers_1767
If you post a saved Prusa Slicer project file someone can demonstrate by modifying the project and posting it back if you want something you can examine to learn the technique. File>Save Project As. That will save a .3mf file. ZIP that file up and attach it here. Must be zipped for the forum to accept the file.