You will be the king of your office with this rubber band gun !
It is very easy to print, working perfectly, shooting the rubbers at least 2 meters away.
It is composed of four different parts : left part; right part; cog and trigger.
It is shooting one rubber at a time, and thank to the 12 positions cog you can put at least 4 rubbers on the cog, so no need of charge it after each shot.
You don't need any screw, nut, spring or glue to do the assembly, it should be adjusted to maintain it closed without anything.
The weak part was the axis of the trigger, so to improve the solidity I finally remplaced the axis of the trigger originally printed with the left part by a steel axis, for my case I just put a M4*15 screw as shown on the picture. Once again, you don't need a nut to maintain it, it should be adjusted with the 4mm diameter hole on the right part.
I put 20% infill for the left and right parts, but 100% for the cog and trigger to get better resistance.
Enjoy, let me know if you think of any improvement to do.