Pen Plotter attachment for CNC chucks

This is an attachment that lets you turn your CNC mill into a pen plotter without any modifications.

The attachment has a stalk that the chuck can grip just like a drill bit or endmill. I've included two versions, one with a plastic stalk and one with a hole for a machine screw (#5 diameter, 1.5 inches or longer) in case the plastic stalk is too weak.