For years I’ve been saving the styrofoam packing that protects the new devices that arrive in our American household. Computer gear especially is sheathed in custom-fit styrofoam armor, and I hated to throw it out because it was beautiful stuff. I took the little bits to the recycling center, but the large, intricate, weirdly organic pieces I stockpiled in my basement. I was just looking for an idea of what to do with them.
A year ago I saw pictures of two styrofoam robots created by Michael Salter at a museum in North Carolina (before he exhibited one in San Jose this past June). They were stunning. Not only was it art from junk, but it looked easy to do. My son and I could handle this. A recycled styrobot would be the perfect geek dad project.
I had five years’ worth of foam accumulated. I had some space in my studio to assemble it. I got my foam cutters handy. So we began designing. The bot had to fit in one story. I also wanted it to disassemble easily so I could move it. I decided to make it in five parts: a torso and four limbs. I would cut the foam when I needed to, but did not want to spend much time sculpting it. I discovered the fastest way to glue the pieces was using silicon seal.
The final Styrobot looks like this:
The Styrobot is made entirely of the foam packaging material that arrived at our house in the last five years. I learned that a styrobot consumes a huge amount of this stuff so several times I was tempted to grab pieces I’d see in other people’s garbage. But the monster was already getting too big. Once you started adding the detail work, you can go through a lot of styrofoam. So I committed to depleting the pile I had, and to use every bit somewhere on the bot.
We worked on it off an on for many many months. This delay was necessary because the silicon glue needs one or two weeks to fully set. It took me a while to figure this out, even though the sealant instructions (which of course I did not read at first) clearly spell this out. I figured that like most glues it would set overnight, but it really does take several weeks for the silicon glue to set if there is any stress or weight on the joint. We used Lexel silicon sealant, which is very sticky, clear, and cheap. I think we went through four tubes of it.
The second major tool needed for a Styrobot is a foam cutter. On Amazon I purchased a Woodland 4-inch hobby version running off a low-volt transformer. The thin wire heats up when the the switch in the handle is slid on. The hot wire slices through the foam easily. It takes some practice to cut square and even, but even kids can get the hang soon enough. There’s always plenty of foam scraps to practice on. There was no replacement wire included with the Woodland, which is a shame because you WILL break the wire eventually. I replaced it with some nichrome wire I had on hand. Overall this tool is handy. Heats up instantly, and for 95% of the time is all you need.
The drawback to the hobby cutter is that it can’t handle foam wider than four inches in its smallest dimension. Some big screen packing overwhelms that dimension, so I built a really fast-and-dirty foam cutter from some steel piping, guitar strings and a model train transformer.
Any number of plans for large foam cutters can be found on Instructables and elsewhere on the web. Main thing is to have a sturdy frame to stretch the wire, and connect the wire to a low volt transformer. I thought a variable transformer such as used for model trains would allow me to adjust the temperature to the proper degree, but I found that it didn’t matter for the set up I had. For the cutting wire I used cheap guitar strings. The thinner strings make a nicer cut, but I found they tend to break quicker. The broader the cut the more pressure you exert on the wire, which tends to weaken when hot.
My son and I had a lot of fun making it. Pick up a piece and glue. Cut and glue. Styrofoam is pretty light, so the entire robot can’t weigh more than 20 pounds. The two legs of the robot are free standing. The torso sits by gravity up the two legs. The two arms hang on the torso via a small styro shelf on the arms. I can move the whole body in pieces in a few minutes. Maybe I should rent him out. Here the Sytrobot hangs out in my office.