Dvd RW have a laser , motors can bild a cnc machine ?
http://www.youtube.com/watch?v=8rWXesRncL8
have at look at these:
http://www.youtube.com/watch?v=kiKOjrTa-ZU&list=WL7813E3D4FB00C9C2
http://www.instructables.com/id/Pocket-laser-engraver/