précession stable

CONT: Mouvement de précession stable d'un gyroscope.
PHR: Être en état de précession stable.

CONT: ... special gyro configurations can be devised by using slow spin velocity for which sizable circular motions are easily induced and observed. When they are superimposed on steady precession (due to unbalance) the result is a nodding up an down of the axle as it precesses about the vertical, which has led to the term nutation.
CONT: The gyro in the artificial horizon can be set in motion and kept in constant motion (steady precession) by using either electricity to power a spinning motor or by using air with a vacuum to suck air out of the casing and vary this air in and out to keep the wheel turning constantly.
OBS: The three elementary movements of a gyroscope: ...1. Rotation--the top is spinning rapidly about its vertical axis. 2. Precession--as it slows down, the top cants over and its axis follows a conical path. 3. Nutation--as the top spins more slowly still, the axis oscillates in a sinusoidal path.