Small Hole Measurement System

The efficient, effective measurement of small drilled holes continues to be a challenge for key aerospace applications. While manufacturing methods for fabricating holes have improved significantly over the last ten years, measurement and metrology methods have not advanced at the same pace. Modern jet engine parts may contain tens of thousands of holes along with the requirement that the aggregate air flow rate through the part be controlled to within 10%. In order to assure that these specifications are met, parts must be periodically removed from the production machine and evaluated using air flow testing, which is a very time-consuming process. The goal of this project is development of a method of measuring small holes that overcomes the primary shortcomings of existing methods, specifically: (1) the need to interrupt the production process to make periodic air flow measurements, (2) the limited accuracy of current hole measurement techniques—especially when used on very small, angled holes, and (3) the inability to correct for inconsistencies in the fabrication process. BENEFIT: The technology developed on this project will provide a new methodology for real time characterization of small holes in precision engine parts. Use of technology is expected to reduce part to part variability and dramatically reduce production time and cost.