EVERY INSTRUMENT IN MY BAND, THE SWAMP DRIVERS, IS HOMEMADE, FROM THE drums and bass to “guitars,” such as a 1-string garden hoe and a 3-string broom. Last December, my frying-pan guitar was featured on the Guitar Player website, and when we opened for the Marshall Tucker Band, they actually brought it onstage to play. However, I’ve always wanted to make a guitar out of Harley-Davidson parts, so I contacted a relative who works on Harleys, and he filled a box with random pieces. After a few weeks of laying things out, I came up with an idea, and I used a chain sprocket, a clutch-lever handle, and gears for the volume and tone knobs. This “Hog-o-caster” is one of the coolest guitars I’ve built so far, and I love…