The example below demonstrates the procedure for machining a curved surface component, in this case a wing section. Roughing

Roughing

This is the first stage of machining where the object is to quickly remove the bulk of the waste material, normallywith the aid of a ripper cutter (see cutters below), this gives the coarse stepped feature seen in the workpiece above. CNC machining, CNC machinings

Semi Roughing

This stage of machining generally uses a smaller cutter than roughing, typically an end mill, although the aim is still to remove the bulk of the waste material.