New Version: https://www.thingiverse.com/thing:3829724
New version has simplified locking system and single piece body
Mechanically actuated ballpoint pen. It is very addicting to play with, and you'll probably annoy the crap out of your coworkers. You'll get annoyed having to explain to everyone what your writing with! The good news is nobody will know how to use it.
Everything is printed horizontally, except for the bottom barrel, and plunger. The spring and ballpoint refill can be stolen from any existing pen. All fasteners are M3. It helps to superglue the top and bottom barrel together.
How to assemble