Parts which have contoured surfaces, such as turbine blades, castings or mold dies, are challenging to setup on an NC machine using the typical tools available to the machinist for these reasons:
The datums on the parts may be derived from the surface contours, requiring a best fit to CAD data.
Castings may need to be positioned in such a way that material is cut from all required areas.
The shape of the part may vary such that the location of machined features is dependent on the surface.
PC-DMIS NC alleviates these problems by allowing the part to remain on the NC machine for the measurement process.