The objective of this study is to design and fabricate a soft bearing balancing machine for rigid rotors, and to develop the PC based operating system. The balancing machine and operating system features that it is simple and convenient to handle input and output data, so that it can be used with ease by a novice, and that it can effectively compensate for the coupling unbalance effect. To evaluate the performance of the system, two rigid rotors are two plane balanced by using the influence coefficient method. The test results show that the balancing machine and operating system developed is capable of balancing rigid rotors at the balance quality grade higher than G 0.4.
