CAD Tolerancing Integration: A Tool for Optimal Tolerance Allocation

Abstract

Tolerance allocation approaches serve as effective tools for design engineers to reduce the total manufacturing cost of mechanisms as well as to improve the product quality. In every mechanical design, the major task of design engineer is to allocate tolerances and clearances to the studied dimensions and joints, respectively, in a mechanism assembly. This paper presents an optimum tolerance allocation tool, based on manufacturing difficulty quantification using tools for the study and analysis of reliability of the design or the process, as the Failure Mode, Effects and Criticality Analysis (FMECA) and Ishikawa diagram. The proposed method is performed to produce, economically and accurately, allocated tolerances according to difficulty requirements. For this, an integrated CAD model is developed using Graphical User Interface (GUI) in MATLAB to expose diverse tolerance allocation approaches that respect the functional and manufacturing requirement. Many examples can be executed using the established GUI in order to highlight the advantages of the proposed approach.