This work focuses on the use of a polymer concrete as a filling material of structural parts to damp vibrations in machine tools. The goal of the overall project is to improve the dynamic behavior of CNC lathe systems by limiting at most the vibrations triggered in operative conditions, in order to guarantee a high productivity of the machine tool while keeping the machining quality of the final products. In particular, this study focuses on the possible design modification of an automatic bar-feeder connected to a CNC lathe. The prototype of a new base filled with a commercial polymer concrete of an automatic bar-feeder was developed and many laboratory tests were performed to analyze the vibration response for different working conditions. This work illustrates the design of the new prototype, the performed experiments, the results of the signal analyses, and some concluding remarks.