CHAPTER II. THE CONSTRUCTION OF SIMPLE TOY ELECTRIC MOTORS.
The Simplex Motor is an interesting little toy which can be made in a couple of hours, and when finished it will make an instructive model.
As a motor itself, it is not very efficient, for the amount of iron used in its construction is necessarily small. The advantage of this particular type of motor and the method of making it is that it demonstrates the actual principle and the method of application that is used in larger machines.
FIG. 8.—Details of the Armature for the Simplex Two-pole Motor.
The field of the motor is of the type known as the "simplex" while the armature is the "Siemen’s H" or two-pole type. The field and the armature are cut from ordinary tin-plated iron, such as is used in the manufacture of tin cans and cracker boxes.
The simplest method of securing good flat material is to get some old scrap from a plumbing shop. An old cocoa tin or baking-powder can may, however, be cut up and flattened and will then serve the purpose almost as well.
FIG. 9.—Showing the Armature assembled on the shaft ready for winding.
The Armature—Two strips of tin, one-half of an inch by one and one-half inches, are cut to form the armature. They are slightly longer than will actually be necessary, but are cut to length after the bending operations are finished. Mark a line carefully across the center of each strip. Then taking care to keep the shape symmetrical so that both pieces are exactly alike, bend them into the shape shown in Figure 8. The small bend in the center is most easily made by bending the strip over a knitting-needle and then bending it back to the required extent.