SELECTIVE ASSEMBLY — ITS ANALYSIS AND APPLICATIONS

SUMMARY The major problem in the operation of a selective assembly plan is “mismatching”, where the number of components in one category does not match the numbers in the corresponding category of the mating component. This is generally because of the wide differences between the natural variability exhibited by the processes producing the parts. The Natural Process Tolerance is defined and its relationship to the tolerance specification established. Selective assembly problems are classified, the design and manufacturing procedures are developed and illustrated by case examples. A case history of a piston-cylinder fit is described, showing how a serious mismatching problem was approached.