ABSTRACT Computer Numerical Control (CNC) machines are an indispensable part of any modern manufacturing system and their precision plays a critical role on quality of the parts produced. Their performance is mainly affected by their mechanical and control components which can be classified under three main categories including software (e.g., control software and interpolators); control hardware (e.g., control devices and related hardware); and mechanical components (i.e., physical structure of the machine). In this regard, every effort is made to make the structure as rigid/strong as possible to minimize any undesired dynamics. This can be partly achieved by appropriate mechanical design and manufacturing of the structural components. However, there are always interactions among the dynamics of the control and mechanical components that degrade the overall performance of the machine. This research is about a comprehensive study of the feeddrive system of CNC machines studying the combined effects of the structural dynamics and their interactions with the control-related components. A dynamic model is developed based on bond-graph technique that is open-ended and can accommodate changes/revisions at the component or system level as required. This model is used in a modal analysis of the system that reveals the effects of different modes of the system on its dynamic behavior. Simulation study is used to analyze system performance under different conditions and the results are presented. The results can be used for controller design and analysis of CNC machine systems; or monitoring applications of machining processes.