LED cube sculpture series

Posted on May 25, 2011 in Hardware, Portfolio

For the 2011 Interactive and Generative Art Exhibition at UNK, I wanted to create a few quick, simple, creative projects for display, and was presented with an opportunity to do so when one of the students mentioned he wouldn’t be able to make the exhibition due to other engagements. His final project was to create an LED cube, then develop some custom animations to display on it. Thanks to numerous tutorials and articles around the web, the design and construction of the cube was fairly straightforward, so he was able to spend more time on the development of custom animations.

However, a single 4x4x4 cube of LEDs does not exactly fill out a 2.5’x8′ table, even if it does have sweet animations! Since this was a project I always wanted to do myself anyway, I decided to produce two more cubes, and put them along side his on the same table to show how else it could be done. To help make things a little more interesting, I constructed two cubes and embedded them each in unique structures, to demonstrate some creative uses for these cool little devices.

As part of his final project grade, this student chose to write up an Instructables article detailing how to build these cubes. Of special note is that both he and I chose to use LEDs that were not diffused, but this is something you really need. So I manually sanded about 130 LEDs myself using a Dremel with a sandpaper bit attachment to get the job done!

Suspended Cube

The first thing that came to my mind happened when I realized just how many wires are needed to control just a 4x4x4 cube (16!). It felt like for such a relatively compact structure, there was an awful lot of “messy” wires that had to be dealt with in some way. So I wondered what a cube would look like if it were suspended in the air by only its control wires, creating a sort of techno-fruit hanging from its relatively complex and messy host structure.

First I built two cubes in exactly the same way, as outlined by the student in his Instructables article (he just showed me how to do it in person at the time). For these cubes, each column needs to have a current limiting resistor (I used 100 ohms), so for this particular cube, I soldered the resistors on without clipping their leads, to make them as long as possible. I then positioned the cube ‘upside down’ to get all the resistors on the top side, then soldered very long wires to each of the columns. I was able to save a little bit of space and reduce overall messiness by using twisted pairs from standard CAT5 ethernet cable (the stuff is fantastic wire, just be sure to cut the insulation correctly!).

Next, I use a couple of screws to attach a long piece of plumber’s tape to a piece of scrap wood, then bent the tape into an arc. I was then able to feed the twisted pairs from the LED cube up through several of the holes in the tape just above the cube, and pull just enough wire through to leave the cube suspended in mid-air. I then ran the cables through some more holes in the base of the structure to reduce mechanical strain, and help organize the wires a little more. I then attached an Arduino clone to the piece of scrap wood using sticky tack (another great building material) and cut and connected all of the LED cube wires to the appropriate pins of the Arduino.

Finally, there was the matter of programming some animations into the Arduino to control the cube. In the interest of time, I downloaded some pre-built code from a user on Instructables who built a very similar cube, though I intend to write some of my own sometime soon.

Shoji Cube

Next, I wondered what the light from these cubes might look like if it were obscured by some uniform diffusing material (like paper), such that an observer would not immediately realize that there is a cube of LEDs creating the patterns and shapes of lights they are seeing. Many months ago, I developed a paper enclosure for a high-powered RGB LED using bamboo skewers, standard A4 printer paper and hot glue (thanks to PKM’s great Instructables article). I really liked the way it turned out, and thought it might look quite nice scaled down for one of these LED cubes, so I replicated the build process on a smaller scale, using some scrap cardboard for a base.

When every LED was wired up, and everything was connected to an Arduino, I applied power and realized I made a really great mistake. I connected some of the columns to the wrong pins! Now, if I were half the engineer my professors want me to be, I’d say, “crap!” and fix it. But I’m either not that good, or too lazy, because I kept it the way it was. I realized that the ordered animations that were programmed onto the Arduino became somewhat disorderly and reminiscent of cellular automata, e.g. Conway’s Game of Life, creating interesting and slightly unintuitive stochastic patterns that were both aesthetically pleasing and intellectually stimulating. If you ask me, those are the kinds of mistakes worth saving!