If you stare at this vintage hypnosis rotating disc machine long enough you probably will find yourself forking over the $1685 required to purchase it.
I wish the website had a video showing the device in motion. It would be a fun how-to project to replicate this.
UPDATE: I forget that Kaden Harris made a hypno disc machine for David!
Dr. Hietrick's Vertigo Therapy. Bi-Directional Rotating Metal Disc (Via Dinosaurs and Robots)