In MAKE Volume 29 we published the Better Nerf Gun project by Simon Jansen. It’s a lovingly hand-crafted Nerf dart gun made from machined metal, PVC pipe, and wood — the kind of foam dart weapon that you might will to your grandchildren as an heirloom.
While the characteristics of Nerf darts and PVC were being explored for the project’s test-build at Make: Labs, engineering intern Dan Spangler came up with simpler and more powerful (if perhaps less elegant) Nerf dart propulsion device: a 1/2″ ID PVC pipe barrel stuck into a capped 2″ PVC pipe chamber, with a flint igniter from a propane lantern installed in the cap on the back.
Warning: Potentially Dangerous Pyro Ahead. To operate the mini dart cannon, one loads a dart into the detached barrel and fills the chamber with fuel from a BernzOmatic mini torch (with trigger pulled halfway to dispense the fuel without clicking the igniter). Then the barrel is fit onto the adapter fitting on the front chamber, and the lantern igniter knob is turned to fire.
One foam dart fired across spacious Labs hit a whiteboard hard enough to create a sizable dent.