Four (4) Inch Round Electrical Junction Box

thingiverse

This is a model for a standard 4-inch outdoor electrical junction box. It should work great for things like motion-sensing lights, overhead lighting fixtures, and whatever else you use round electrical junction boxes for. I'm personally using it for motion-sensing lights. There are two versions of the model: one for 1/2-inch PVC conduit threads and one for 3/4-inch PVC threads. You should be able to customize it pretty easily via the included .scad file. Hint: You probably want the 1/2-inch version, that's what you'd get if you bought something similar at the hardware store. **Note:** You'll need the OpenSCAD Threads library to use the included .scad file: http://dkprojects.net/openscad-threads/ Both models have the same screw hole layout and should work with #10 screws, which is what you're supposed to use with these fixtures. The outside mounting screw holes are slightly larger in order to be more appropriate for screwing the box to your house or whatever, using common exterior screws. I highly recommend using some dielectric grease around the perimeter (top) and in the hole threads when screwing things into them to ensure everything stays water-tight. You also might want to use some washers when screwing the box to a wall/ceiling/whatever. **Note:** For this to be compliant with the US National Electrical Code, if using 110-120V, you need to print it in a flame-retardant filament (or resin) that is UV-stable. Alternatively, you could just coat it in some UV-blocking paint or spray, like Krylon UV Protect Gloss. **Minor update (20180525):** I updated the .scad to use 'inside=true' for the threads since that's the correct value for that type of thread. Just increases the size of the threaded holes ever so slightly to more correctly match the NPT spec. The models have been re-re-rendered and updated as well. I TAKE NO RESPONSIBILITY IF YOU INJURE YOURSELF OR ANYONE ELSE OR IF YOU START A FIRE USING THIS MODEL. YOU HAVE BEEN WARNED.