CD 1966050 E&MP31.003
MAY 5 1932
There can be no guess-work in the construction of electrical machinery. No matter how large and powerful the motor, every dimension must be correct to the proverbial eyelash.
Another essential is dynamic or rotating balance. Not only must the weight of an armature be the same in all directions from its axis but the weight must be distributed at balancing distances from that axis. Otherwise there would be an eccentric, lop-sided effect that would tear the whole motor to pieces.
Special machinery and delicate instruments are used in the East Pittsburgh works of the Westinghouse Electric and Manufacturing Company, to be sure each armature is in dynamic balance before it leaves the shop.
Original Caption by Science Service