Tracer controlled milling machines are equipped with copying capabilities through tracer control,

and hence car reproduce or duplicate external or internal geometries in two dimensions.

The machine consists of a worktable provided with longitudinal and transverse motions, a tracer head and spindle head mounted on the cross rail. A template or a pattern whose shape is the replica of the shape to be produced is placed on the worktable and below the tracing spindle head.

The workpiece to be machined is also placed on the worktable and below the cutter of the milling head. The stylus or probe is brought in contact with the template to start the operation. The stylus follows the profile of the template and guides the cutter movement synchronizing with the table movement, to produce a similar profile as on the template. The movement of the stylus is controlled through electronic or hydraulic systems.

Tracer controlled milling machines are used for machining cams, grooves, contoured surfaces etc. Die sinking and other processes involving the machining of cavities can be done on three dimension profilers or duplicators.