Abstract: This study investigates the effects of structural flexibility, support boundaries and motion-chain torsional compliance on the closed-loop response of a medium-large direct-drive turntable. Finite-element modal analysis of the base, table and complete assembly is compared with accelerance FRFs and CMIF results from hammer tests. Measured peaks in the 299-326 Hz range are close to the fifth and sixth assembly modes, while the 385.9 Hz peak lies in the dense 380-394 Hz range of the eighth to tenth assembly modes. Peaks in the 50-100 Hz range reflect support and global-motion effects not fully represented by the current model. An anti-slip and equivalent torsional-stiffness model is established for the bolted flanges, and the motion chain is represented by a motor-side/load-side two-inertia system. The model is coupled with the torque motor and cascaded servo loops to analyze low-frequency tracking response and dynamic error. Static-compliance equivalence and first-torsional-mode matching produce stiffness parameters with different physical meanings. The calculated 292.603 Hz peak is not directly associated with the 299.1 Hz structural peak obtained from vertical hammer excitation. The proposed approach provides a basis for coupled structural and control modeling of direct-drive turntables.