Camera Parts: Winding Sprockets

Of the camera parts inside a film camera body, winding sprockets are small and frequently ignored, but cause major headaches if broken.

What Are Winding Sprockets?

On a roll of 35mm film, there are notches punched into the sides. Inside a camera, these fit into gears called winding sprockets. By spinning the sprockets, the camera can pull the film, advancing it for the next exposure. These sprockets are made of plastic or metal, and are attached to either the motor drive or the film advance lever.

Problems with Winding Sprockets

Since the winding sprockets pull the film to the next exposure, if they fail, film will not be advanced. This will lead to overlapping exposures if it pulls incompletely, or if they fail completely, one piece of film being exposed over and over. Either way, broken winding sprockets can make a camera useless.

Usually, it is not the sprockets themselves that break, but rather the gearing attached to the sprockets. Film needs to advance a specific amount and a slipping gear is most often the culprit. However, sprockets can break as well, especially if made of plastic.