Development of a low cost Touch Trigger Probe for CNC Lathes

The use of Touch Trigger Probes for CNC Machine Tools has become a world standard, mainly due to the reduction of machine setup time and the ability to promote workpiece accuracy on-machine measurements. However, some barriers still need to be transposed, like the measurement routines programming difficulties, high costs of these equipments and the low number of technical literature about this subject. This work presents a review on the applications of Touch Trigger Probes on shop floor, discussing nowadays technologies used to generate the trigger signal. A new Touch Trigger Probe model based on a simple electrical contact is proposed, with the needed characteristics and low cost, to be used for CNC Lathes. The tests of the probe developed in the laboratory shown a repeatability of 0.003 mm (±3 s or 99.73% confidence interval). Those characteristics seem to be highly comparable to most needs for lathe applications in industries.