Excitement, twice removed

One of the guys who works here (at Stevens) used to work for Flir http://www.flir.com/
He always had stories to tell about the place.

Today we were talking about motors and bearings (the circulating fan in my gas fireplace is on the fritz) and he tells us this story about the infrared cameras. They used a very small detecting element, a beryllium lens, a couple of oscillating mirrors and a spinning mirror to scan an image. The motor driving the mirror spun at 20,000 rpm on ceramic bearings. The whole assembly is mounted inside a hollowed out billet of aluminum with walls about one inch thick. The billet is about the size of a small coffee can. Sometimes the bearings in the motor would seize up and the whole thing would crater. The OUTSIDE surface of the aluminum block would appear to be covered with pimples from the impacts of pieces of disintegrating motor on the inside of the block.