This is a simple fusebox with LEDs that will show you instantly when a fuse blows. If an LED is lit, the fuse is good!
Quick note about the picture: I only had one bolt partially in when I took the picture. It accepts bolts on all four corners with no problems :)
I got frustrated with the poly-fuses often used on 3D printer boards. They are typically undersized and extremely unreliable, blowing even when you are below their rating. Instead, I wanted a fused solution with easy-to-find automotive fuses.
The face plate holds the fuses and can be attached to the enclosure with almost any-length M3 bolts. The enclosure is deep enough to allow you to use crimp-on spade connectors without trouble. If you find the enclosure is too deep for you, simply scale it on the "Z" axis - the screw holes go all the way through almost to the back.
For schematics, list of materials (BOM), and build instructions, see my blog post here:
IMPORTANT: I purposefully did not include mounting holes on the enclosure. I personally hate it when folks include mounting holes as they very rarely line up with everything and I end up with either ugly holes or have to take a chunk of time to remove them from a model before printing. It is far easier to drill holes (or add them to a model) than they are to remove.
You can easily add holes to the model for your purposes in programs like 123D or online services like TinkerCAD.com. Likewise, you can pick up a drill online or from places like Harbor Freight or $20.
I personally love 3M's double-sided, permanent adhesive tape for small things like this. I actually used exactly that to mount the box on my 3D printer to great affect.