I'm working on building a DrawBot similar to Sandy Noble's awesome Polargraph. http://vimeo.com/24647023My goal is to use a spool for monofilament line, rather than a beaded cord. This spool is designed to press-fit together on a piece of monofilament line and then press-fit the spool onto the stepper motor shaft.You can follow my DrawBot build log progress on my site: http://makerblock.com/2012/01/drawbot-the-assembly-part-iii/