Interlinking dimensional tolerances with geometric accuracy and surface finish in the process design and manufacture of precision machined components

A wide range of electromechanical devices are made up of a variety of miniature high precision mechanical components machined to very tight dimensional tolerances, geometric accuracy and surface finish. The predominant feature in producing these components is that the dimensional tolerances, geometric accuracy and surface finish must be achieved simultaneously as it is difficult to improve any of these features discretely in subsequent machining/finishing operations without affecting the others. While no firm or universal rules can be laid down to produce these components to exacting tolerances, the process design and engineering play the most important role in interlinking the tolerance levels which can make the difference between success or failure. This paper deals with some of the critical aspects of the process design and engineering of particular examples of high precision miniature mechanical components used in inertial devices.