Abstract: A dynamical analysis on a mass fixed at the tip of a massless flexible rod mounting on a rotating rigid body is presented in which the motion of the mass is kept in the plane of rotation as small deformation of the rod is assumed. For the rigid body undergoing a constant angular velocity the centrifugal forces and Coriolis force on the mass are considered. There exist two dynamic frequencies in which the first order dynamic frequency decreases with rotational velocity up to zero that is associated with a limit rotational velocity of the system. The motion trajectories of the mass in the rotational plane at different rotational velocities exhibit multiple traces with respect to the conventional line trace and may be split into the non-eccentric and eccentric portions. With a view on the change of amplitudes a critical rotational velocity is discussed.