A pretravel model for vertically-oriented touch trigger probes with straight styli. A triggering force model based on principles of mechanics was derived and used as the basis to develop the pretravel model. Experimental probing data were used to show that the model can effectively predict probe pretravel in various approach directions. In applying the model to predict probe pretravel, only one model parameter needs to be calculated from the probe calibration data. The pretravel model presented in this paper is robust and can be used to reduce probe pretravel in vertical probe applications.
