Dynamics of the arch-type reconfigurable machine tool

Reconfigurable manufacturing systems (RMS) address challenges in modern manufacturing systems arising from product variety and from rapid changes in product demand. This paper considers an arch-type reconfigurable machine tool (RMT) that has been built to demonstrate the basic concepts of RMT design. The arch-type RMT was designed to achieve customized flexibility and includes a passive degree-of-freedom, which allows it to be reconfigured to machine a family of parts. The kinematic and dynamic capabilities of the machine are presented, including the experimental frequency response functions (FRFs) and computed stability lobes of the machine in different configurations. A comparison of FRFs and stability lobes of the arch-type RMT reveals almost similar dynamic characteristics at different reconfiguration positions. These similar characteristics arise because the dominant mode where chatter occurs is due to the spindle–tool–tool holder assembly. Consequently, to ensure consistent dynamic behavior regardless of reconfiguration, a desirable dynamic design feature for RMTs is that the machine's structural frequencies are less dominant than the structural frequencies of the spindle, tool and tool holder.