This article was originally published 20 years ago, in Gear Technology’s first issue. It describes a method of
evaluating the smoothness, or lack of smoothness, of gear motion. This lack of smoothness of motion, known as
“transmission error,” is responsible for excitation of gear noise and problems of gear accuracy and sometimes has a relationship to gear failure.
Quality gear inspection means doing the "right" inspections "right." A lot of time and money can be spent doing the wrong types of inspections related to function and doing them incorrectly. As we will discover later, such things as runout can creep into the manufacturing and inspection process and completely ruin any piece of data that is taken. this is one of the most important problems to control for quality inspection.