NEW YORK, N. Y.
Printed in U. S. A.
Copyright 1918
by
COLE & MORGAN, Inc.
CHAPTER XII. HOW TO MAKE A DYNAMO-MOTOR
It is very difficult to construct a first class dynamo without resort to the materials and methods employed in the manufacture of commercial machines. The necessity for careful workmanship in every detail, can hardly be overestimated. Poor workmanship and poor materials will always result in an inefficient machine. Telegraph instruments, toy motors, etc., may be constructed from all sorts of odds and ends of materials, and they will work fairly well, but in order to make a real dynamo it will be necessary to use certain materials for which nothing can be substituted.
[Illustration: FIG. 123—Front view of the Field Casting.]
The field casting must be soft gray cast iron and the magnet wire should be of good quality.
Both the field and the armature of the small dynamo described in the following pages are cast iron and patterns will be necessary in order to form the moulds for the castings. It may be possible for several experimenters to club together and make the patterns, or have them made, for building this dynamo.