Horseshoe door sensor

What's the most natural object to hang above a doorway? A good luck horseshoe! Be sure to turn it right way up, so you don't spill the luck.

This is a 3D printed enclosure for the TinyDuino Wi-Fi Door Sensor.

The door sensor electronics are small enough to fit inside a considerably thickened horseshoe. I've subtracted the shapes of the hardware from the horseshoe, making them fit nice and snug. You have the option of turning the horseshoe upside down (with the ends facing down). In that case you can put the reed sensor into either end of the horseshoe. I've carved out a small space for it on both sides as well as paths to route the wires.

Here's the original model itself, free to download and print:

Horseshoe door sensor

I recommend 3D printing this enclosure and spraying it silver. Or better yet, printing it with the new stainless steel PLA! That material wears the printer nozzle quite fast but I think it's worth doing to get that cast iron look. A replacement nozzle isn't all that expensive. My local Fab Lab allowed me to print a horseshoe as an experiment. Many thanks.

I sanded the horseshoe by hand, because a power tool spins so fast that it would probably melt the PLA. First I used a coarse 300 grit paper to remove most of the print layer marks, then 600 grit, 800 grit and finally 1200 grit to get a nice shine.

When the enclosure was looking nice and uniform I grabbed the 300 grit paper again and scratched the hell out of it. I also took a saw blade to it to get some deeper scratches. There, a nice worn horseshoe with some character.

I asked a photographer friend of mine whether I could borrow his camera for a minute because my phone wasn't picking up enough details. He ended up doing a whole photoshoot in his studio.  

The ideal way to nail the horseshoe to the wall is with proper horseshoe nails. But how far you take this is entirely up to you, of course. Sticky tack will do just fine.