Pen holder plotter converter for CTC or Replicator Printer

I wanted to see if I could use the CTC printer as a plotter so I created a pen holder gadget based on the mounting system of the active cooling fan.

Since I liked the mounting system of the Active cooling Fan Duct it is kinda the same design and even uses the clip stls from that thing; check it out:
http://www.thingiverse.com/thing:537918

To facilitate different pen sizes the pen holder should be an exact fit for your pen to allow it to slide up and down. The elastic belt should provide