The paper presents the results of a research of the stability of a rigid homogeneous rotor with a symmetrical relative to the middle arrangement of radial EMB, supported in the vertical direction by an axial EMB. In the first part of the work, the researches were held using a proportional-differential regulator in the system. In the second part of the work was considered the impact of the control function parameters in the cases of instantaneous generation of the displacement signal and with delay.