Duplicating Device

an attachment for a metal-cutting or woodworking machine (lathe or milling machine) used in shaping curved surfaces that cannot be produced only with the types of feed made possible by the design of a given machine. When such a device is used, one type of feed (usually the curved feed) is produced by a master cam and provides complex motion of the cutting tool corresponding to the required shape of the surface. There are many design versions of duplicating devices; their features depend on their purpose and on the type of machine with which they are used. All duplicating devices have a master cam, which may take the shape of a template or washer. The master cam is in contact with a cam follower. When the cam and the cam follower move relative to one another, the cutting tool reproduces on the blank the required surface shape. The connection between the cutting tool and the cam follower (which is in contact with the master cam) may be direct (rigid) or through a servomechanism.