Kinetic Contraptions: Build a Hovercraft, Airboat, and More with a Hobby Motor
To my parents who took my piles of junk seriously
ix Acknowledgments Gustavo Hernandez our magnificent co-coordinator at the Watsonville Environmental Science Workshop was a genuine treasure in preparing troubleshooting honing and giving fresh perspective on this set of projects His enthusiasm for helping kids to learn from these sorts of projects is unbounded The hundreds of Watsonville kids served by the Science Workshop were also invaluable in testing and giving feedback I trust they enjoyed building the projects as much as I did Gustavo and Fabiola Pizano also helped set up and pose for the photos after hours Thanks to Paul Doherty for checking the science content All remaining errors are my own Thanks to Jerome Pohlen at Chicago Review Press for being an editor with a genuine human touch perhaps one of the last Thanks to Rory for the laptop on which this was written Like folk tunes science projects such as these are continually being changed and improved upon as they pass hand to hand shop to shop I’ve given credit at the end of each project section if I can recall where I picked up the idea whether or not that was its true origin
1 Introduction Blenders hair dryers car starters vacuum cleaners power drills CD DVD VHS and cassette players refrigerators heaters and AC units washers and dryers air compressors electric toothbrushes cell-phone vibrator units ceiling fans and remote control cars what do these things have in common They are all powered by electricity but also by magnetism because an electric motor lies at the heart of each of them Electric motors are amazing devices You put in an electric current and you get out a rotating shaft Attach something to the shaft and it will rotate as well Over the 19 decades that these devices have been around they have done a lot of work for humankind Today people without access to electric motors spend a lot of time and energy doing things that are effortless for you and me such as washing clothes In other words no more whining when you have to move your clothes in and out of two machines that basically do all the work for you Large electric motors power ski lifts pumps elevators some buses and more and more family cars You usually have to get some sort of technical degree before you get to play with these types of motors But small is also beautiful Nowadays you can buy motors smaller than your pinky for a few bucks You can find the least expensive commercial motors about the size of your thumb for around 60 cents You can also get one for free by ripping it out of an old toy There is no reason not to have several of these motors sitting around your house to explore and experiment with I have been tinkering with small motors since I was eight years old As I selected the projects to include I realized that they are just the tip of the
2 Introduction iceberg Dozens of brilliant projects are possible with the low-cost low-tech components and building techniques described here so don’t stop with what’s in this book Bump it up a notch baby and create a truly original kinetic masterpiece to call your own But don’t spend any money on it I’d love to hear from you if you come up with something magnificent If it’s a truly original kinetic contraption masterpiece I’ll make you famous in the next book You can e-mail your ideas to me at information curtgabrielson com Happy tinkering Electromagnetic History and Accidental Science On April 21 1820 the Danish scientist Hans Christian Ørsted was fiddling around with some parts he used to make electricity and magnetism demonstrations Among other things he had wires batteries and a compass Upon connecting a wire across a battery he was startled to notice a twitch in the compass which was laying near the wire This was arguably the most important discovery of the 19th century It was the first direct connection observed between electricity and magnetism Up until that time the phenomena associated with these two areas while astonishingly similar in many respects were always thought of as separate Today all modern motors transformers tube-type video screens solenoids electromagnets and magnetic storage devices are made possible through our understanding of this link Even the electric lights you are using to read this are almost surely powered by a faraway generator a device which essentially uses magnetism in motion to create electricity We can learn two key lessons from Ørsted First it rarely pays to have your workbench too neat and clean you may miss the most important discovery of your time Obviously this is a message your parents must hear Second casual tinkering combined with careful observation can lead to great stuff So if either your science teacher or textbook gives you the message that science happens through a lockstep process in which trained professionals traverse a well-known road toward the next great scientific discovery you must stand and shout Balderdash A long list of earth-shaking history changing finds including among many others X-rays and radioactive decay small-pox vaccine Teflon matches penicillin polyethylene glass and DNA were stumbled upon by fiddling and tinkering all the while looking closely at what was happening
