Lunchbox Laser Shows

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Back in the 1970s, my friend Wayne Gillis and I used to do light shows at science fiction conventions. We had the usual panoply of overhead, slide, and custom-made projectors, and a single, very expensive, helium-neon laser from Edmund Scientific. Calling ourselves Light Opera, and later, Illuminatus, we performed at... Read more »

One-Ton Linear Servo

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RC hobby servomotors were just made for hacking. What’s not obvious is how much you can hack them — with a few tricks, you can use a servo to control almost anything. Hobby servos consist of a DC gear motor, a potentiometer (usually 5K), and a control circuit. The output... Read more »

Router Trammel

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This attachment mounts in place of your router’s factory baseplate and is used for cutting circular disks from, or boring circular holes in, sheet stock. It pivots about a small pin rotating in a blind hole drilled in the center of the stock to be cut. This one is based... Read more »

Digital TV Coat Hanger Antenna

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Television antennas are comprised of a series of metal rods cut to exact lengths and positioned so they receive a particular television frequency. The following design was invented in the 1960s by an engineer named Doyt Hoverman. It is particularly sensitive in the UHF frequency range, the same range used... Read more »

Self-Disinfecting Toilet Brush

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What do you do with the toilet brush right after you use it? Hang it up? Lay it in the sink or bathtub to dry first? Or maybe you have one of those brushes with a built-in base that keeps the bristles corralled when not in use. All of these... Read more »

No-Holes Poster/Quilt Hanger

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I’m a great admirer of Jørgen Møller’s Posterhänger design. It’s great for those in-between prints that are too valuable to put thumbtacks through, but not valuable enough to have framed. Plus it’s considerably cheaper than framing, and looks a lot better than thumbtacks. Plus, it’s easier on your walls, requiring... Read more »