Cutting process monitoring with an instrumented boring bar measuring cutting force and vibration

We present an industrialized version of a boring bar with embedded sensors and electronics that measure cutting forces and vibration. The novel tool gives the operator or process developer valuable insight into the cutting process in components like jet engine shafts and landing gear. Critical events like chatter and excessive insert wear can be detected and avoided and the quality of the cut can be documented and compared with earlier cuts. Since the deflection of the bar is proportional to the cutting force, the actual machined diameter is measured in real time which reduces the need for dimensional probing between cuts. In addition, the vibration measurement gives an indication of the quality of the machined surface and can reveal problematic cutting parameters or component features. We present results from machining in both Maragin 250 and steel that clearly shows the potential of the technology.