Off-axis machining of NURBS free-form surfaces by fast tool servo assisted turning
The manufacture of optical components with complex geometries like freeform surfaces is getting more and more important. Mass production of those optics is enabled by replication methods like injection molding. Ultraprecision technologies like Fast Tool Servo turning are required for the machining of such mold inserts with freeform geometries. The NURBS data format is highly applicable for the description of freeform surfaces. Hence trajectory generator based on NURBS data has been developed for Fast Tool Servo assisted turning, which is generating online set points with a continuous and smooth trajectory. An approach of increasing the efficiency of manufacturing freeform surfaces is the off-axis machining of multiple work pieces at the same time. The paper presents the different process steps in simulation and off-axis machining of freeform surfaces using Fast Tool Servo assisted turning.