Improved single-face lapping by using an air bearing supported lap

Abstract

Lapping is a finishing process extensively used in the engineering world for those parts that require a fine finish surface such as gage blocks or flats for checking production parts. Nowadays, there are several machines in which single-face, double-face or rotating lapping processes can be carried out. Generally, all these machines use a rigid bearing system for supporting the lap shaft and a flexible coupling to connect that shaft to the motor. Therefore, their vibrations can affect the surface finishing of parts to be lapped. One way to reduce that effect and greatly improve the surface quality is to use an air bearing. The present work is aimed at investigating the lapping parameters when using an air bearing system. For comparison purposes, tests using a conventional rigid system were also conducted. Results show vibrations have a negative effect on flatness and roughness, reason for which lapping can take longer time to reach the same results obtained with an air bearing system.