Yet another pen holder for Prusa i3

This is non invasive, gravity pen holder for original Prusa i3 printer. Pen is mounted on extruder stepper motor. Holder is designed for Edding 0.3mm pen for drawing PCBs but is slightly modifiable in OpenSCAD file.

Pen holder in action can be seen on YouTube video https://www.youtube.com/watch?v=Mq9V-7Mj8eU