3/4" Extension for 4" Electrical box

thingiverse

This is a 3/4" thick spacer for use with a 4" round electrical box, typically used with lighting fixtures in ceilings. 1/2" spacers are available at most hardware retailers, but at the time of writing, they are ridiculously over priced. Additionally, I need a 3/4" extension, because I plan to use SonoPane sound proofing board, which is thicker than regular drywall. Thus, I made my own. The small holes should be tapped for a 6-32TPI screw. If you're using a softer material, you might be able to cold-form the threads (i.e. stick the screw through and let it make its own threads), but if you're using a brittle material (such as resin) you'll definitely want to tap the holes.