Sean, of the aptly named Sean’s Crafts, builds things out of every day materials like rubber bands, straws, magnets, and cardboard. This video shows off a homebrew NERF style blaster that fires up to six darts. It’s a fast run through, but the build should be easy for a hobbyist to replicate.
He’s done more complex builds, as well – like this two player pinball set up. Check out his YouTube Channel for more.