mrhasan shared this print on YouMagine:

I wanted to accomplish three specific things with this project: 1. Make some that is kid friendly and can be used as a toy 2. Make it as simple and fun to build as possible 3. Use little to no parts apart from the printed ones And I ended up designing this mini crossbow. A simple crossbow would be truly a boring thing to design or make so I wanted to add a bit of extra to it. So I ended up designing a mini crossbow that have manual forward/backward motion via four wheels, left/right and up/down via manual gears. This models put a check mark next to all the three things that I planned on incorporating: it is kid friendly (and can be very colorful!), it is simple, yet fun to build (you will see!) and it uses only a regular rubber band (and the NERF dart; couldn’t do anything about it).