While perusing the stepper motor offerings on eBay in April, 2003, I happened across an auction for a lot of 200 small steppers. Normally, I would not be interested in these, as they are too "coarse" (24 steps / revolution for my eggbot course. But they were also incredibly cheap ($69 buy-it-now). This created an opportunity I had been thinking about for a long time: exploring a stepper array. After some promising initial experiments, I bought 1,080 stepper motors for around 40 cents a piece.
To control such a large number of motors,I turned to the Twin Cities Robotics Group for help. One member suggested this interesting piece: "The Wooden Mirror," by Daniel Rozin. But this is only one way in which a motion controlled array might be used. After some more experiments, we decided on a hexagon pattern that resembles coral (see above right). This allows for 7 x 7 x 7 = 349 motors.
The project proved extremely laborious since everything had to be done 349 times. I was greatly helped by my friends Alan and Jeff from the robot group who laser cut the "petals" and created the circuitry to control so many motors. As an expedient, we attached colored surgical tubing to the end of each motor to make the spinning visible. With some basic programming, Animanemone can create ripples across its surfact that appear to respond to user interaction--something I would like to add one day.
Today, Animanemone (Ani for short) is great for demonstrations and exhibits, but it is waiting for more advanced software and possibly some proximity sensors.