Technical LEGO: Blacklight ravographs

When I was told that the blacklight “FX“ produced by these Spirograph-like LEGO gizmos are straight out of a rave, I dubbed them “ravographs“. Each ravograph is a basically a single-stage planetary transmission with no sun gear and a long input shaft coupled directly to the planet carrier. As the carrier is turned by hand or motor, the planet gears roll around the inside of the 48-tooth “annulus“ (internal gear) without slip. One of the planets then drives a “crank“ with a strongly fluorescent “generator“