Online 3d software apps are horrid

[fred_dot_u]

Enclosure MK2 has fewer problems, all of which seem to be the same type.

enclosure mk2 mm check.jpg

I'm hopeful that the above image can be clicked to enlarge in order for you to see the red lines indicating fail points. In Meshmixer, the automatic repair pretty much failed, by completely removing the corner pillars and all four walls. On close examination, I can see that there are overlaps of the bottom wall and the right wall, which creates a non-printable area within the corner. It appears at first that the lower wall and the left wall are separated, but they also have an internal overlap.

Are you working from an engineering drawing with dimensions and locations? If so, I would accept that information from you and create this box within OpenSCAD, a script driven descriptor type 3D modeling program. Because it is parametric, it is certain to create a manifold model ready for printing, unless there's an error in the script, of course.

I could attempt the creation of this part by guess-measuring from Meshmixer, but that's a royal pain and I'm not skilled enough in Fusion 360 to use that program to measure it.

If you intend in the future to create 3D models, Fusion 360 would be a good choice, as it is very powerful. Of course, with great power comes great responsibility. In this program, the responsibility is taking on the task to learn a complex piece of software!

[3Dn00b]

@fred_dot_u
Im not sure as what all you need so:
L = 5.5in(139.7mm)
W = 6.25in(158.75mm)
H = 1 13/16(46.0375mm)
Wall, Base, Lid = 1/8in(3.175mm) thick

Blue = RPi standoffs
Yellow = Power Distro Standoffs
Orange = 2-CH relay standoffs
Black = Lid
Enclosure Mk2 (2).jpg
^^That is what I am trying to make. Unfortunately, SketchUp doesn't have any way of showing overlaps or malformed planes.