Expansion-tolerant

The Design of a machine, equipment or device is expansion tolerant if it allows for the effect of expansion. When seeking to ensure Tolerance for expansion, it is crucial to have data on the behaviour of the relevant components and assemblies when exposed to changes in temperature.

In the case of components, the coefficient of Thermal expansion represents the mean value over a continuous temperature range. The coefficient of Thermal expansion varies according to the Material and temperature in question.

A number of parameters determine how the length of a component changes - the coefficient of linear expansion$\alpha $, the length of the component and the mean change in temperature. When the coefficient of linear expansion$\alpha $ is known, it can be used to calculate the area and volumetric expansion of the component.

The design must tolerate expansion, which means that the position of each component must be clearly specified. The number of degrees of freedom afforded to each component must not compromise its proper functionality. A fixed point is first defined for this purpose. Guides that have only one Degree of freedom are then allocated to this fixed point for the required directions of movement.