Dynamic Measurement of CNC Part Paths

Abstract

The current procedure followed to manufacture a new part by CNC machining is to write the part program, machine a test part and measure the test part for conformance to the required dimensions and tolerances. If the test part dimensions out of tolerance, the part program is modified and the process repeated until a successful part is machined. In many applications, such as the aerospace industry, where material cost and machining time are high, this iterative process becomes economically unacceptable. Research has been conducted to test the feasibility of using the Laser Ball Bar (LBB), a spatial coordinate measuring device, to measure dynamic continuous-path contours of CNC part programs to micrometer accuracy prior to machining. In this way, a virtual test part can be measured and compared to the design drawings to validate the CNC part program. This reduces or eliminates the costly and time-consuming steps involved in the machining of physical test parts.