TOLERANCE STACK ANALYSIS FOR ASSEMBLY

Studies have indicated that design for manufacture and design for asse mbly have a significant impact on the success of a product. One of the key issues is tolerance specification and thus it is important for th e designer to consider tolerance analysis thoroughly in the early stag es of product development. With minor modifications and if used proper ly, tolerance charting can be a valuable tool to the product designer. This paper illustrates two methods used to tackle tolerance balancing for assembly and provides an insight into the considerations to be ta ken into account. A manual method first demonstrates the fundamental c oncepts while a computer aided version further enhances the charting p rocess. The latter is easy to apply and renders greater flexibility du ring problem formulation. Consequently, what-if analysis is possible a nd thus better results can be achieved. However, it should be cautione d that tolerance charts are merely tools; the results they produce can only be as good as the inputs they receive and thus a 'perfect' solut ion cannot be guaranteed. Nonetheless, tolerance charting is an effect ive diagnostic tool as it provides tolerance analysis in the early sta ge of products development.