I had a little time last Saturday afternoon, and I decided to build a model of a lighthouse for my baby daughter's play area. And rather than just 3d printing a model, I decided to make it a bit more engaging - I've been playing with Adafruit Neopixel rings recently, and thought that they'd be really good to make a working lantern part of the lighthouse, without needing any to construct any moving parts.
I used AutoDesk 123D to design the lighthouse - I've included an exploded drawing of how all the different pieces are arranged. I was careful to make sure that any overhangs are 45 degrees or more so I didn't need any support material on my 3d printer.
I made sure there was a small lip on the parts making up the main tower so each part snugly fits into the part below.
The trickiest part was the bezel for the Neo-pixel - I've shown a picture of the piece below - there's a groove on the left side for the wires soldered to the back of the Neo-pixel ring.
I printed each of the individual pieces using my Prusa i3 Mk2 printer, with red, white and black PLA. In total it took about 10 hours to print all the parts.
I used a LM2596 DC-DC Step down voltage converter to convert a 9V battery output to 5v, and then used this output to power an Arduino Duemilanove. I then connected this to a Neopixel ring with 24 LEDs, using a simple sketch (included in the code section below), which uses the Adafruit Neopixel library. I added a little bit of complexity by making the rotating light from 3 LEDs, with a red LED in the middle and a white LED on either side. I chose those colours because of the main tower's colour scheme, and obviously if I chose a different colour scheme, Neo-pixels allow me to chose different colours.
The finished result
The video below shows the model lighthouse in action - I've uploaded all the CAD files and sketches to GitHub, the details are below.
This was a simple project which was quick and easy to build, and uses some simple electronics and programming to create the effect of a rotating lantern.
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