Noncontact 3-D Digitizing and Machining System for Free-Form Surfaces

A 3-D digitizing and machining system with a non-contact displacement sensor is introduced in this paper. This system consists of an NC milling machine, a personal computer to convert geometric model data into the NC driving data and a non-contact digitizing sensor for a free-form surface. This sensor, with a measuring range of 20mm and resolution of 11 μm/pixel, can measure the displacement of the free-form surface within an accuracy of ±50 μm for a steep inclined surface up to ±75 degrees. The system can not only measure, but also machine the free-form surface such as 3-D model shapes for injection mold and pattern.