Abstract: The present invention relates to a process for setting up a vertical gyroscopic device mounted on a moving craft, wherein the action of roll reset means is eliminated only with a delay time with respect to the rotation of the mass, this delay time being such that upon its expiration the kinetic moment of the mass in rotation is sufficient to ensure the stability thereof and the erector system is controlled in the sense of activation only with another time delay necessary to reduce the movement of precession of the device. The invention is applicable to the guiding or control of missiles or aircraft.