Increasing milling stability predictions accuracy considering speed dependent spindle behavior with an automated measurement device

Manufacturers seek to enhance productivity by investing in high-speed machine tools. However, at elevated spindle speeds, dynamic characteristics of spindles may change due to thermal loads on bearings, complicating the task of finding optimal spindle speeds. To address this issue, an automated measurement system was developed to evaluate dynamic characteristics of tooling assemblies under rotating conditions. The system employs a solenoid actuator for excitation and capacitance probes for response measurement. Dynamic measurements and milling tests were conducted on a 5-axis milling machine tool and benefits of the system in improving accuracy of stability prediction are presented.