Boeing Internship Keystone: Fixture Tolerancing Project

Introduction

My first internship through the MECOP program at Oregon State University was with The Boeing Company. I served as a Tool Design Engineer Intern at their Gresham, OR part production plant during the Spring and Summer quarters of 2020. My resposibility was to support tooling needs throughout the plant, which produced complex, high-strength metal structures and mechanical components that would form the underlying structure of Boeing commercial aircraft. My most notable accomplishment during my stint as a Boeing engineer was the successful re-tolerancing of a complex N.C. (numerically-controlled) machining fixture. 

Research & Development

Upon recieving the assignment, I first sought out personnel in various on-site departments who might know about the issue, met with several of them, and began scoping out the project. I found that the existing fixture's tolerance scheme had been developed long before the modern machinery presently in use was implemented. The newer machines were able to adapt to the fixture's old tolerance scheme; however, the machine often consumed a majority of the tolerance leeway available, leading to occasional part scrap and material waste. This was exacerbated after the aircraft part in question was revised with tighter tolerances. The machine was now frequently unable to adapt, using up all available tolerance before the parts were finished, and causing defective parts to become a regular occurrence.

Now understanding the problem in-depth, I undertook some preliminary GD&T (geometric dimensioning and tolerancing) coaching, and worked closely with my internship mentor to devise a solution. The process dragged on over multiple weeks as I pushed to coordinate with the right people and maintain momentum. The main difficulty in this process was not so much the availability of specific personnel, but rather their willingness to prioritize my project over their work to enable progress. Through this I learned the nuance of 'selling' my project from a high-level business perspective, as well as the value of persistence without being pushy. In the end I was able to bring together multiple cross-disciplinary engineers for several design reviews, and with my mentor's help I was able to produce a winning tolerance scheme redesign. 

Outcome & Conclusion

The redesign involved a few minor physical changes to the fixture, allowing the N.C. machine to establish a new, native coordinate system that relinquished the amount of available tolerance consumed by the previous revision. After recieving concurrence from senior-level engineering staff, I was able to release my project, and even witness the ensuing rework begin before the end of my internship. The benefit to the company was a significant reduction in production downtime, as well as a measurable offloading of pressure from the quality control department. Besides resultant savings per part, a significant amount of material was also conserved as a result of consistently "good" parts being produced, requiring no rework – a very rewarding realization. Below is the final report that I wrote after my internship at Boeing, which summarizes my overall experience at the company and discusses my various projects, including a more in-depth overview of this one. Thank you for reading!