Precessing Gyroscope
Top-down view: the arm sweeps around the pivot at the precession rate Ω while the rotor spins fast about its own axle at ω. Ω = τ / (I·ω), from gravity torque τ = m·g·r.
Torque τ-
Moment of inertia I-
Angular momentum L-

Precession Ω-
Precession period T-