Maker

feet short of the magic mile mark. The 20,000-plus people attending the Punkin Chunkin love to watch the big cannons at work, for there’s something undeniably interesting about a mile-shooting pumpkin gun made, for the most part, by regular Joes working in their garages and driveways.

Each gun is designed differently, and each has its own personality. Big 10-Inch is an engineer-designed gun that hides its top-secret workings behind an opaque covering. There are long, skinny cannons encased in spidery metal superstructures, such as Skybuster, Fire and Ice, and Please Release Me. There is the Harley-vibed Bad Hair Day, a gun crewed by a leather-clad female team, and the venerable and patriotically themed Old Glory, a former world record-holder that is always a favorite with the local crowd.

The technology behind these big blasters is not complicated, more a matter of scale than of high-

The Harley-vibed Bad Hair Day is a gun crewed by a leather-clad female team; the venerable Old Glory is a former world record-holder that’s always a favorite.

tech engineering. The barrel of an air cannon is simply a large-diameter steel or aluminum pipe, usually scrounged from an industrial or agricultural scrap heap. The door and pumpkin-holding area inside the cannon are called the breech. Often this is simply a bolt-on steel plate near the bottom of the barrel and a grate on which to hold the pumpkin in place.

The basic principle of air- or gas-powered cannon operation is simple: rapidly introduce a powerful push of high-pressure gas from nearby storage tanks into the breech of the cannon and, in doing so, push the pumpkin out of the barrel as forcefully as possible. Valves control the release of the high-pressure air. The valve design is critical: a too-small valve, even if it opens very quickly, will retard the accumulation of pressure inside the gun and hinder performance. A big valve that opens too slowly will do the same. The most resourceful builders incorporate a big,

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fast-acting group of valves that instantly open the floodgate of high-pressure air or gas.

This competition isn’t about money or trophies or even the teardrop-shaped mass of gooey pumpkin flesh a mile away in the middle of a Delaware farmer’s field. It’s about pride. It’s about being the best, about setting a goal and achieving it. When told of the time and money invested in making these guns, a lot of people simply smile and shake their heads. But not real makers. Real makers understand.

See the Maker File video episodes from Punkin Chunkin: makezine.com/blog/archive/the_maker_file.

William Gurstelle is a MAKE contributing editor. He wrote “Happy Blastoff” for MAKE, Volume 10.