High performance machining: A practical approach to high-speed machining

High-speed machining (HSM) has become a popular topic in CNC machining methodology in recent years. Simply defined, high-speed machining is a methodology to improve machining throughput by using higher-than-normal spindle speeds coupled with extraordinarily high feed rates without compromising the quality of the finished part. However, in practice, HSM is not a straightforward methodology to implement. In addition to the higher spindle speeds, numerous other factors like feed, chip loading, width and depth of cut, cutter path, tooling, machine construction, CNC-machine controls and CAM software all impact the HSM process. Most conventional CNC machines are equipped with a spindle with lower rpm limits (under 12,000 rpm), so the term "high performance machining" is adopted (HPM). Applying HPM methodology requires the manufacturing engineer to possess in-depth knowledge of the limits of the CNC machine and how to work around them. An initial investment into discovering the limits of any CNC machine is critical to applying HSM techniques to non-specialized CNC machines to obtain high performance machining. This paper briefly addresses the basic concepts of HSM. Then a methodology taught at Arizona State University for systematically determining the high performance machining envelope for a CNC machine is described. A studentimplemented case study of this methodology resulting in significant performance gains of machining an automotive part is presented.