This is a derivative of Makerbot's Unicorn Pen Plotter ( http://www.thingiverse.com/thing:4185 )

Basically, this is a direct adaptation of the unicorn assembly - all I did was break it down into a small number of printable parts. Pretty straightforward, and should go together pretty easily. One thing I changed was the extruder controller mount, figuring that it's better to use a separate mount like http://www.thingiverse.com/thing:4174

Now if only you could have the pen plotter and the extruder integrated so that you only need one controller and wouldn't need to swap toolheads. Hmmmmmmmm...

1) Print each part
2) Assemble with the hopefully soon to be forthcoming Makerbot servo and linear rail kit - otherwise purchase a linear slide and servo
3) Plot as usual