my textbook says: "As a gyroscope precesses, its center off mass moves in a circle with radius r in a horizontal plane. Its vertical component of acceleration is zero so the upward normal force exerted by the pivot must equal mg." Now wouldn't this always be true. I mean if u have a flywheel attached to a pivot and at first dont let it spin. Then the weight of it produces a torque that makes the arm rotate till it hits something, e.g. itself or the table it stands on. But its not translating linearly, so isnt there also a normal force exerted upwards by the pivot in this case? It just doesn't produce a torque since it's distance to the rotation axis is zero.