Pen-Like launcher

Simple; you cock back the bolt, lock it, and when you are ready, gently push the pin to the side and boom!

Its great. For the springs tho, you may have trouble finding one that suits it!

Spring should be about 6mm of diameter. For the length, its up to you to choose, it changes the power: more length, more power.

The instructions to assemble it are in the images.

The print orientation is indicated in the all in one 3d file. DO NOT USE SUPPORT(exept for the bolt!)