To say the least, my midterm project did not go exactly according to plan. I had a really grand vision of what the finished product would be: a game about the absurdity and dangers of first-strike nuclear policy. Its setup would be divided into three pieces: a P5 sketch of a submarine instrument panel, a set of arcade style buttons to control onscreen actions, and a nuclear mushroom cloud that would be triggered at the inevitable conclusion of the game.
The part I was most excited to work on was probably the least important part: the mushroom cloud. It involved working with materials I didn’t usually get to work with: chicken wire and polyester fiber fill. I bought the smallest amount of chicken wire I could, and still, it was a huge amount to cut and shape into a cloud.
Once I had the basic shape, I used spray adhesive to attach the fiber fill onto the chicken wire. The appearance was quite satisfactory and I began to test how it looked with different LEDs inside of it.
In the video below, you actually see a single 3-Watt LED running through a series of colors.
The effect of both light and color was ideal, but meant that my power management would be a bit more complicated (I would need to use my variable power supply to juice it up rather than just going through my Arduino). I also tested my LED strips inside the cloud. The results were similarly satisfactory, though the individual LEDs were more visible than was ideal. However, the LED strips also allowed a sort of “rising action” where the lights could move throughout the cloud and change color. I already had some NeoPixel-based code working in Arduino for this action, so I decided to move forward with two LED strips, each 15 LEDs long, for the final piece.
At this point I made my first big mistake. While only the top half the cloud was completed, I tested to see if I could pull it using fishing wire attached to a continuous servo motor. I made the mistake of not testing up/down motion against gravity, but rather, just saw if the motor was able to drag the cloud along the length of the table.
I have a photo of how I attached the fishing line to the motor, and you’ll note that it is probably not the best way to handle the problem. I was using the base of the spinner attachment as a sort of bobbin, circling a few rounds of the fishing wire there, and then attached (by way of a tenuous knot) the wire to the spinner itself.
Danny later recommended attached a proper bobbin to the servo, so that I could avoid the tangles that inevitable resulted from my haphazard setup.
At this time, I had essentially setup a breadboard version of my final product. I had switches programmed to serially communicate with a p5 sketch, and trigger the LEDs and motor at the appropriate moment. It sort of worked, when gravity wasn’t working against me!
At this point, I went back to building my mushroom cloud. Up until this point, I had only the top of the cloud completed. Without its bottom, more-mushroomy half, it was a bit too friendly. I completed the rest by using the same chicken wire and fiber fill combo as before. Later, I’ll learn just how I underestimated the weight of the cloud after these additions.
The next piece I worked on was a contraption for hanging the mushroom cloud. I initially wanted to avoid hanging the cloud from the ceiling, and instead, created an L-structure from found plastic “tubing.” Because the found piece was one long piece, I had the opportunity to use the bandsaw for the first time! Like so many things, it was intimidating until I tried it. Cut the long piece into two piece (which were rough 1/3 and 2/3s of the original piece), with a 45 degree cuts where the pieces would join. I applied an acrylic glue at the juncture to connect the two pieces, and reinforced with some tape.
In order to thread the fishing line through the tubing, I tied a hexangonal nut to one end of my line and used a few magnets to drag that nut through the length of the tubing.
I was going to attach the L-structure to a wall for my final setup, but I soon found that the structure was not quite sturdy enough for what I needed to do. It tended to lean forward when my mushroom cloud was attached. Thanks to the last minute advice of a fellow student, I ultimately abandoned the structure altogether and instead, decided to rely the bars we have on our ceiling. I hung my mushroom cloud on one the bars and connected it back to my servo motor, which was attached beneath the table.
The rest of the setup consisted of a set of arcade buttons to control the on-screen p5 sketch. There were a lot of firsts in this project – to house the arcade buttons, I decided to lasercut a box based on a design I created using the online tool at makercase.com. The box came out really well! I glued together all but the top panel, and enjoyed relatively easy access to the wiring I placed inside.
Unfortunately, I don’t have a photo of the final setup. To briefly describe the scene: it was a monitor displaying the p5 sketch with the arcade box placed in front. The mushroom cloud loomed behind the monitor, and unfortunately, even in its final iteration, was a bit to heavy for my tiny servo to lift at the appropriate moment.
This was only one of many disappointments. The one piece that always worked reliably in testing was the lights, but this too failed during the presentation, thanks to a loose wire. The p5 sketch and the game portion of all this was very, very simple and I really didn’t have a chance to build in the complexity of action/reaction into the player choice. Instead, it was a rather straight march towards doomsday (with a bit of serial communication thrown in).
This is definitely a project where I learned a lot and failed a lot. I chatted with Danny once it was over, and he suggested some ways to make better use of the servo and its native torque (and some of the advice is noted above). I also felt as though I had broken down my project into too many components that had to come together perfectly in order for a relatively uninteresting interaction to work at all – and much of the physical computing really kicked in at the very end with the mushroom cloud. It was a bit much for one person to do in one week, but I did learn quite a bit in a very short period of time.