Investigation of a Multi-Cone Variant of the Standard Cone Frustum Test for 5-Axis Machine Tools

In the domain of CNC (Computer Numerical Control) machining, both positional and contouring accuracy are of extreme importance. Moreover, the need for higher precision and more complex freeform surfaces has reduced component geometric tolerances and increased the demand for higher process capabilities. 5-axis machine tools (or machining if you prefer) have enabled realization of these surfaces availing of full tool posture control, while also reducing set-up and production time. However, identification and quantification of associated errors is a challenge, often time consuming, with full physical correction near impossible. This paper's focus is on the repeatability and functionality of the cone frustum acceptance test presented in the draft standard 2012, ISO 10791-7. This work builds on the state of the art and proposes that the artefact used in the standard cone frustum test be developed to include two or more conical surfaces. Explanation and investigation of the Multi-Cone artefact, with machining results on a Mori Seiki NMV1500, are reported. The results show the repeatability of the cone frustum test and the potential for diagnostic benefits using the Multi-Cone artefact.