Improving the accuracy of large scale monolithic parts using fiducials

Monolithic machined components are rapidly replacing sheet metal assemblies to reduce labor costs. As these monolithic parts become larger, maintaining the accuracy required for further assembly operations becomes difficult. The long-range accuracy and the thermal environment of most machine tools become the limiting factors for part size. This paper describes a solution to this problem using fiducials, the spacing of which is based on the machine accuracy and part tolerance. Experimental results demonstrate the validity of the technique. This technique can be extended to allow small machines to manufacture large components and is also applicable in high volume manufacturing environments.