LEGO technic pen holder

This is a pen holder intended to mount a pen (or other object) to LEGO Technic bricks using the mounting holes. The pen is held parallel to the pins. To hold the pen perpendicular to the pins, check out the pen holder from The Tinkering Studio:
http://www.thingiverse.com/thing:1486961

The pen holder requires a 1/4-20 fastener for a set-screw, and the set-screw hole should be chased with a 1/4-20 tap prior to use.