The Distribution of Tolerances

In a previous article the statistical tolerance stack-up analysis is discussed. It is usually profitable to do a statistical tolerance stack-up analysis instead of a worst-case analysis. A worst-case analysis often leads to low tolerance specifications and therefore...

Statistical Tolerance Stack-up Analysis

In the article Worst-case Tolerance Stack-up Analysis you read about the worst-case or linear stack-up analysis. In such an analysis it is assumed that all dimensions in the tolerance chain have worst-case deviations form their nominal value. In a statistical analysis...

Worst-case Tolerance Stack-up Analysis

Suppose that you went through your tolerance analysis step plan and made a tolerance chain. The only thing to do now is to add up all tolerances. This seems easy enough but there are a few questions to consider: What to do with asymmetrical tolerances? Do you perform...

Tolerance Stack-up Analysis

Tolerances become important as soon as you design an assembly of parts. Of course each dimension must be provided with a tolerance. But in an assembly the tolerances become important because all parts must fit. In this article I tacitly will assume that we are dealing...

Flexure hinges: theory and practice

The flexure hinge is a tried and tested construction element in precision engineering systems. It is created by drilling or spark erosion of two adjacent holes. The positive properties of flexure hinges (free of play and friction) are partly undone by the limited...