For a similar, but more complete, description (with figures), see "Feynman's Tips on Physics," Section 4-10, The Spinning Disk, and "The Feynman Lectures on Phy

For a similar, but more complete, description (with figures), see "Feynman's Tips on Physics," Section 4-10, The Spinning Disk, and "The Feynman Lectures on Physics," Volume I, Section 20-4 Angular Momentum of a Spinning Body. Mike Gottlieb Editor, The Feynman Lectures on Physics Coauthor, Feynman's Tips on Physics