So you would like to get your hands on a robot capable of drawing amazing patterns? This XY Plotter Drawing Robot kit has you covered. It is a belt-driven plotter that can work with various tool heads. It has a working area of 210mm x 210mm and max speed of 30mm/s.
The robot is based on Arduino UNO. It moves a pen and other tools to create works of art. More info is available on Etsy.