Accuracy of a reverse-engineered mould using contact and non-contact measurement techniques

Abstract

Investigations into the accuracy of computer-aided design (CAD) models for an injection mould have been carried out in this work. Taguchi design of experiments has been employed to find appropriate values for scanning parameters which result in shortest scanning time and lowest deviation between actual mould and its CAD model. CAD models obtained from point clouds captured using different scanning techniques, such as laser line scanning probe, active scanning probe and passive scanning probe attached to a bridge type CMM, have been analysed. For analysis, deviations between CAD model and actual part have been measured at a number of pre-defined points. Effect of surface roughness on the accuracy of reverse-engineered CAD model and scanning time while capturing surface coordinates using scanning touch probe has also been investigated. This investigation clearly exhibits that in case of polished surface higher accuracy for CAD model can be obtained in shorter scanning time.