Thus, the idea behind the robot costume with LEDs on top was born. While this project took me a fair amount of time, most of it came as a result of a number of mistakes I made during the design and building process that I had to go back and fix. Luckily, though, you won't make these mistakes: they will be marked off as warnings or things to note.
I wanted to keep the basic structure simple and limit it to materials you could find very easily. That resulted in the end appearance of the costume, which sort of looks like these but the guitar-based digi-bongo acapella-rap-funk-comedy folk duo was not the inspiration for this costume by any means.
Special thanks to randofo, lamedust, tetranitrate, bradpowers and fungus amungus for their help and for letting me borrow various items.
The full picture gallery is on the last step.
Step 1: Materials
Two Cardboard Boxes. These will act as the head and the body; the body one should be substantially bigger than the head. My box dimensions were: a 1 foot cube for the head and 19.5 inches by 23 inches by 29 inches for the body. The 1 foot cube is standard (and I actually could not find an appropriate box so I built my own. I just cut out five 1 foot by 1 foot squares and taped them together firmly with duct tape--see pictures), but the size of the box for the body is variable. Pick a size that fits and that you can find.
Duct Tape: For taping.
Aluminum Tape. For taping that needs to be shiny.
Electrical Tape. Only a small amount, and just to tape down the wires so they don't get in the way.
Aluminum Foil. I used aluminum foil to cover the robot because I didn't want to use spray paint and I wanted a shiny look. However, spray paint would be a viable, and in some cases, easier, alternative.
Wires: Very standard solid hookup wire. I used red and black so that I could easily keep my positives and negatives straight when wiring.
LEDs: 12 single-colored LEDs. WARNING: If you want to use a mix of colors, make sure all of the LEDs have the same resistance--otherwise your circuit won't work.
Solder. For soldering.
Switch. An SPST switch.
Battery and Battery Holder: 9V Battery.
Resistor. 220 Ohms.
Duct. For the arms; I got the cheapest one I could find. Note that they stretch, so a small one should be plenty.
Latex Gloves. For the hands.
Assorted Trash. To fill the hands.
Boxcutter or Knife. To cut the cardboard.
Soldering Iron. For soldering.
Scissors. Cutting tape, duct, etc.
Ruler. Robots apparently only like crisp, straight lines.
Wire cutter and wire stripper. Preparing the wires.