Predicting geometric tolerance thresholds in a five-axis machining centre

NC-Checker is a software tool used for monitoring and validating the geometric performance in modern machining centres. Threshold settings allow the Manufacturing or Maintenance Engineer to customise the tool based on specific job or industry tolerance requirements. In order to perform effective long-term monitoring, this has the potential to skew the perceived health state of the machining centre as presented in the NC-Checker benchmark reports. This study brings attention to this fact and its relevance in the pursuit of enhanced levels of automation for geometric performance monitoring tools, in preparation for the machine shop’s transition to Industry 4.0. A sense-check function is proposed to identify unusual alterations based on historical data, utilising a support vector machine methodology to develop a predictive classifier. The models achieved predictive accuracy scores of 87.5% during validation, acquisition of a suitable testing set is under way and the predictive models will be evaluated upon completion.