New submitter melarky (3767369) writes This is a fun weekend project that most nerds will appreciate. Step by step instructions and also a handy video will make the construction of this project fast and easy. I have seen lots of plans for sale (or actual guns/kits for sale), but couldn't seem to find any plans for free. I played around with a few different designs (even cut my first few on a homemade CNC machine) and finally landed on this design. I made the guide more accessible to the general public (no need for a CNC machine here), so if you've ever dreamed of ending friendships because of hundreds of rubber band welts, now's your chance! We'd like to see your home-made projects, too.