Circuit Playground Arc Reactor

This was one of those projects that came about not because I really wanted to do it, but because I had some hardware lying around that was needing a project to put it to use.

With my Adabox 006 from Adafruit, I got my hands on a Circuit Playground Express, which along with just an all around fun device to play with, gave me my first set of Neopixels to play with. Combined with some transparent filament I got for Christmas, I definitely wanted to do something that glowed. I kicked around a bunch of different ideas, but definitely due to the circular arrangement of the Neopixels on the board, decided to try my hand at making an arc reactor out of it which at it’s core is really just a 3d printed housing for the Circuit Playground Express.

The design was all done in Shapr3D on my iPad, with some measurements of the Circuit Playground Express and using some references pictures from the internet. I went with the Mark I variant of the arc reactor. It’s just cool and grungy and I figured that grungy effect would be easier to paint and pull off than something clean and polished. Definitely more forgiving. Here’s what it looked like within Shapr3D. With the design done, it was just a matter of cutting up the model and getting it ready to print.

3D printing on this was pretty straightforward. Most of the pieces required some sort of supports, but they weren’t too bad to deal with. I printed it in probably more pieces than were necessary, but it made it easier to paint when it was all done, and allowed me to spread the printing time more easily across a couple days instead of trying to do one big print session.

Once it was all printed, it was onto the usual process of sanding the pieces to get a nice finish, covering them in XTC-3D, and the sanding once again, just to get as smooth a finish as possible to start with. Once the surface was as good as it was going to get, it was onto painting. Each piece started with primer and a base coat of spray paint, with details being hand painted with a combination of some basics acrylic paints and some silver rub & buff which is just magic if you want to do any 3d printed pieces that look metallic. After several coats, I finished it off with some polyurethane to seal in the paint.

After that was assembly. Most of the pieces are just glued together. The exception to that was the top transparent section to the rest of it because I’m just not committed enough to this project to glue in my Circuit Playground Express permanently (I used tape and command strips) and some artisan copper wire for the “wire” parts of the build.

The final step was getting the Circuit Playground Express to glow when plugged in. While you can use python to program the board, I instead opted for trying out MakeCode from Adafruit when you can program the board using drag and drop blocks, which worked well for this project. Check out the completed project below: