Although elemental gear inspection is rarely specified for molded plastic gears, the measurementequipment
and practices can be valuable in advancing the molding processes and improving the quality of the molded
gears. After a brief description of plastic gear tooling and molding, this paper gives examples of specific
elemental measurementsand relatesthem toprocesschangesand qualityimprovements. Such examplesfor
spur and helical gears include: profile measurements leading to gear mesh noise reduction; lead
measurement leading to increased face width load distribution and, continuing from that, even to the molding
of crowned gears; and index measurement leading to improved roundness of gears molded from fiber
reinforced plastic materials.