So now that the hard part was over (writing the animation sketch for my Arduino) I started on the fun part, making the Arc Reactor a wearable Halloween prop.
About halfway through my build I found a great post on building a prop Arc Reactor on Instructables by msraynsford which used most of the same materials I had picked for my own. Great minds think alike I guess…
I picked up a rectangular PCB at Radioshack to mount my LEDs to. It seemed like a secure way to keep everything in place while wearing it, plus an excuse to brush up on my soldering skills. I used a scroll saw to cut the PCB into a 4 inch round. Then mounted the LEDs on the board spaced in an even ring (note: the extra LEDs pictured on the PCB would have resulted in my Arduino turned into a pile of slag and were removed). I also used this time to drill a couple of holes in my Altoids tins for holding my 9v battery and Arduino board.
Cutting PCB to size
4 inch round PCB
LEDs mounted in a ring
After cutting the PCB to size I soldered the LEDs and resistors to the board and some lengths of hookup wire so I could feed them directly into the board for testing.
I had my fingers crossed the whole time and as you can see from the video everything worked just as expected. Somehow I managed to do it all without soldering my fingers together.
Now that I had a working board I cut off the ends of an old serial cable and used the 8 conductor wire to extend the hookup wire. I added about 2 feet of wire or enough to reach the battery pack I planned on keeping in my pocket and wired a 9 volt battery to the Arduino board for power. I also hot glued the hookup wires into the outputs on the Arduino board. From what I’ve seen online this is the best semi-permanent way to make connections on the board and comes off with a little rubbing alcohol. Then fit everything snugly into my two Altoids tins so I could easily fit the battery and Arduino around in my pocket.
Ready for soldering
Just enough wires for the job
The modeling plastic I used comes in a container as small white plastic beads. When heated with hot water they turn transparent and mailable like a firm clay. As it cools it returns to a very hard white plastic. Since this happens fairly fast I wasn’t able to take any pictures of the molding process. I used items I had around the house with shapes similar to what I wanted to see on the faceplate and pressed the plastic around them. Then while the plastic was still warm I stretched it around the sides of the PCB and allowed it to cool. After cooling it held on really firmly to the board. I also velcro’ed a pocket on the inside of a t-shirt to hold the arc reactor while I was wearing it. The Arc Reactor and Arduino ran for over 8 hours on one 9 volt battery (I left it on over night so I’m not sure of the exact time).
Below are pictures of the finished Arc Reactor.
And the final video
Overall I’m pretty happy with how it turned out. I’m planning on taking what I learned and trying to get my hands on some laser cut metal parts for next year. I’d like the Arc Reactor to look as cool outside of the shirt as it did inside.
