Effect of cutting conditions and tool geometry on process damping in machining

Process damping can be a significant source of enhanced stability in metal cutting operations especially at low cutting speeds. However, it is usually ignored in stability analysis since models and methods on prediction and identification of process damping are very limited. In this study, the effects of cutting conditions and tool geometry on process stability in turning and milling are investigated. The previously developed models by the authors are used in simulations to demonstrate conditions for increased process damping, and thus chatter stability. Some representative cases are presented and verified by experimental data and conclusions are derived

Robots in machining

Robotic machining centers offer diverse advantages: large operation reach with large reorientation capability, and a low cost, to name a few. Many challenges have slowed down the adoption or sometimes inhibited the use of robots for machining tasks. This paper deals with the current usage and status of robots in machining, as well as the necessary modelling and identification for enabling optimization, process planning and process control. Recent research addressing deburring, milling, incremental forming, polishing or thin wall machining is presented. We discuss various processes in which robots need to deal with significant process forces while fulfilling their machining task

Use of inverse stability solutions for identification of uncertainties in the dynamics of machining processes

Research on dynamics and stability of machining operations has attracted considerable attention. Currently, most studies focus on the forward solution of dynamics and stability in which material properties and the frequency response function at the tool tip are known to predict stable cutting conditions. However, the forward solution may fail to perform accurately in cases wherein the aforementioned information is partially known or varies based on the process conditions, or could involve several uncertainties in the dynamics. Under these circumstances, inverse stability solutions are immensely useful to identify the amount of variation in the effective damping or stiffness acting on the machining system. In this paper, the inverse stability solutions and their use for such purposes are discussed through relevant examples and case studies. Specific areas include identification of process damping at low cutting speeds and variations in spindle dynamics at high rotational speeds