Marvelous Magnetic Machines: Building Model Electric Motors from Scrap

You’re standing in front of an old card table in a driveway at a garage sale. On that table is a one-quart aluminum saucepan, a votive candle holder, pieces of some office machinery, and a wooden awards plaque. What do you see there? If you did not answer “a six-cylinder radial electromagnetic attraction motor,” then you need this book!H.P. Friedrichs (author of The Voice of the Crystal and Instruments of Amplification) returns this time to explore the principles behind the operation and construction of  five simple, yet impressive, model electric motors.Aspiring mechanical model makers are often discouraged by their lack of access to machine tools, like mills, lathes, or drill presses. Friedrichs demonstrates that with some basic knowledge, an open eye, and a sharp mind, one can use commonly available (and often discarded) parts and materials to engineer one’s way around any lack of expensive machine tooling. In fact, every motor in this book was built from scrap, and can be assembled with hand tools.You’ll learn where to hunt for and find materials, and where to salvage suitable bearings. You’ll know where useful solenoids can be extracted from scrap, and how to fabricate bobbins to wind your own. You’ll learn how to time your motors, fashion a connecting rod, make a commutator from scratch, use a hall effect sensor to detect magnet position, use a transistor as a switch, and much more.

H.P. Friedrichs is a degreed electrical engineer (BSEE), inventor, and author with more than three decades of experience working in domains ranging from audio, medical, and radio, to software, automotive, and aerospace. At present, he is a Principal Engineer with Honeywell, involved in the design and support of specialized equipment used for testing and validating aircraft power generation products. He has five U.S. patents to his credit and holds three radio licenses including Extra-Class Amateur (AC7ZL), Commercial Radio Operator with Radar Endorsement and GMDSS Operator/Maintainer with Radar Endorsement. He is also a certified VE. Friedrichs is the author of numerous technical articles appearing in a variety of magazines, newsletters, and web sites but is best known for his books The Voice of the Crystal and Instruments of Amplification. Now cult classics among "from-scratch" electronics experimenters, these books have enjoyed favorable reviews from the editors of such prestigious periodicals as QST, CQ Magazine, Practical Wireless, and Make Magazine. H.P. Friedrichs lives in Tucson, Arizona, with his wife and his German Shepherd/laboratory assistant ― who is prone to "borrow" books and tools but not return them.