Our assortment of gyroscopes are excellent for demonstrating precession as conservation of angular momentum. Use the strings to wind them up to high enough angular velocity.
Initially, their angular momentum should point (approximately) vertically. As gravity tips the gyroscope, the angular momentum vector points off at some angle. This decreases the vertical component of the angular momentum vector. To conserve angular momentum, the gyroscope precesses. This precession adds to the existing vertical component of angular momentum that arises from the gyroscope's spinning, maintaining the original vertical component of angular momentum.