This thesis focuses on horizontal balancing machines for industrial rotors, with particular reference to subcritical machines with hard-bearing supports. In these systems, the quality of unbalance measurement depends not only on the acquisition system, but also on the structural behaviour of the machine base, the rotor supports, and the load path through which the dynamic forces generated by the rotor are transmitted. The work begins with a general analysis of the operating principle of balancing machines and their main subsystems: machine base, rotor supports, drive systems, phase and speed detection system, piezoelectric sensors, and signal acquisition chain. Starting from this framework, the study addresses the design and standardization of a new line of machine bases for horizontal balancing machines, covering rotors from 30 kg up to 50 tonnes.