Identification of scanning errors using touch trigger probe head

Purpose: Creation of a mathematical model, which combine ball tip radius error and small tilt of the stylus to determine translational motion (in two directions) of the stylus ball centre, due to the surface slope. Design/methodology/approach: First error is described on two dimensional model, thus is very simple. Second model is based on 3D-mathematical model, which is a basis to determine (and plot) translational movement of the stylus ball according to surface slope. Findings: Accurate scanning process on freeform surface with touch trigger probe head could not be performed, due to number of reasons connected to the stylus ball and trigger probe head errors. Research limitations/implications: According to nature of this problem, 4D, 5D and 6D-graphs could not be plotted, which would define translational motion of the stylus ball centre at any slope surface. Practical implications: Understanding the physical model for described error is a basis to create mathematical compensation error model. Originality/value: No such mathematical model to determine translational motion (in two directions) of the stylus ball centre was published in any paper before.