Modular Mac mini mounting rail

This is the final version of the Mac mini holder and/or extra cooling solution. All components are mounted on a standard 80/20 rail of 40mm by 40 mm. This is giving flexibility in the assembling of the construction. In the design I took as much as I could into account that a 3D printer can’t print all the constructions (e.g. overhangs) I make or it needs to use lots of support material. After exporting the Fusion 360 file to a version to the *.step format the holders is standing upside down in the viewer. I couldn’t figure out why this is happening.