  We consider the system of a two ball automatic dynamic balancer attached to a
rotating disc with nonconstant angular velocity. We directly compare the
scenario of constant angular velocity with that when the acceleration of the
rotor is taken into consideration. In doing so we show that there are cases
where one must take the acceleration phase into consideration to obtain an
accurate picture of the dynamics. Similarly we identify cases where the
acceleration phase of the disc may be ignored. Finally, we briefly consider
nonmonotonic variations of the angular velocity, with a view of maximising the
basin of attraction of the desired solution, corresponding to damped
vibrations.
