Practical Dynamo Building A Practical Treatise Showing the Construc- By Arthur J. Weed Member of the New York Electrical Society SCIENCE Illustrated by sixty-four original engravings showing New York The Norman W. Henley Publishing Co. 1919 621212 Σ PREFACE THE little machine herein described was designed to furnish practical instruction for the electrical student and a very large number have been constructed for that purpose. Being very small and light, they are especially valuable in class work, and are used for this purpose in some of the colleges and schools. The complete dynamo weighs but little more than five pounds, and is small enough to be passed around at a lecture as a practical illustration. At many of the Manual Training Schools and State Colleges, the construction and winding of these little dynamos has formed a portion of the shop work of the students. In efficiency, they are the equal of any small dynamo built and if the mechanical work is carefully and correctly done, the little machine can be put to practical ouse either in generating current or as a motor for light power. Elect They have been successfully used to furnish current to spark coils for gas-engine ignition, and a dozen of the machines fitted with special ball bearings, in a [iii] large New England wire mill, are used to spool up very fine copper wire as fast as it is drawn. In preparing this little book, the author has endeavored to give the instructions for the different operations as clearly and concisely as possible, without regard to literary excellence. The illustrations, particularly those showing the actual operations in progress, will be of great help to the amateur and student in the construction of such a machine. ARTHUR J. WEED. CONTENTS Long and short yoke pieces—Building up the field— Hard fiber-Drilling and turning core-Fitting to brass ring-Locating positions of screw holes-Drilling and Chucking the casting-Drilling, boring and reaming- |