Spherical cutter and method for machining a curved slot

A multi-axis computer numerically controlled machine comprising:

• a spherical cutter mounted to a rotatable spindle of the machine,
• the spherical cutter including a spherically shaped body having an open end and a closed end defining a central cavity,
• multipoint cutting edges disposed along a circular rim at the open end of the body, and
• the spherically shaped body generally defined by a radius and an origin located along a rotational axis of the spindle.

A method for machining a cylindrical workpiece or blank to machine a plurality of circumferentially spaced apart integral rotor blades extending radially outwardly from a hub, the method comprising:

• a step of machining a deep curved slot with a spherical cutter,
• the spherical cutter including a spherically shaped body having an open end and a closed end defining a central cavity,
• multipoint cutting edges disposed along a circular rim at the open end of the body, and
• the spherically shaped body generally defined by a radius and an origin.