hektor
I really want to see Hektor in person.
Hektor is a Graffiti Output Device. … Hektor consists of a suitcase which contains two electric motors, a spray-can holder, toothed belts, cables, a strong battery and a circuit board which is connected to a laptop and controls the machine. The motors that are mounted onto the wall suspend the can holder through the toothed belts and define its position by changing the length of these belts.
Think vector images transferred to a wall by motor. There’s great documentation, images and movies at their site.