Geometries in computer-aided tolerance charting

Abstract

We address some key issues pertaining to geometric tolerancing and propose a simplified method to solve working dimensions and tolerances in 2D space. Geometries that exhibit characteristics similar to linear dimensions are identified. With minor changes, geometrical control requirements can be expressed as ‘equivalent’ dimensions and tolerances and can be applied to a tolerance chart directly. The conversion schemes for short-listed geometries will be tackled accordingly. We also focus on how the process links can be derived from the process plan and outline the strategy to achieve the optimal tolerance mix or combination. An example is included to demonstrate the methods used.