[Raul] built a CNC hot wire cutter that he uses for cutting shapes out of foam. His device uses two flat bed scanners to provide two planes of motion. One scanner arm has the foam mounted on it and provides the Y-axis movement. The other scanner has the hot wire mounted on it and provides the X-axis movement. The cutting wire is mounted on a flexed bow made from heavy gauge coat hanger wire.
He tapped into the logic board of one scanner to gain access to the motor movements. The other is connected through a couple of H-bridges. Both are controlled by an Atmel AVR ATmega128 which in turn takes its commands from a connection with a computer printer port. A python program uses vector graphic files in SVG format and traces the outline for cutting.