After much fiddling and monkeying around with a model airplane linkage and homemade bell crank, I’ve gotten the wig wags swinging like they’re supposed to. The signals (with the dummy control box at the base deleted) and the motor drive unit are from American Limited kits while the detector units are infra-red IRDOT circuits from Micro-Mark. A tiny spring inside the wig wag signal head pulls the target away from the pole. A piece of black thread attached to the top of the target shaft runs over to the pole and down inside it. Under the layout, the thread makes a ninety-degree turn and connects to a bell crank. A rod transmits back-and-forth movement to the bell crank from a lever that follows an eccentric cam rotated by an electric motor. When the detectors tell the wig wags to shut off, a circuit in the drive unit keeps the motor powered until the targets are hanging straight down as if by gravity.
Charley
