API Services Creates “Jig Reference System” for Aeronautical Engineers, Inc. Assembly Fixture

After determining the scope of work, the team at API Services went onsite with the state-of-the-art Radian Laser Tracker to verify the fixture. Inspecting the fixture, as it was built, API found critical locators at the lower side of the door to be 0.040” out of tolerable position. The locators holding the periphery of the door frames were found to be 0.188” out of square. Also, the fixture had to be rotated on trunnions to complete assembly work, and the trunnion centers were found to not be concentric as necessary. This error caused the entire fixture to twist 0.065” out of tolerance when rotating. There were also critical locators missing from the fixture which the fixture builder was unsure how to manufacture and install.

The number and severity of problems with the assembly fixture meant that re-work was going to be necessary bring the fixture back into specification. To solve as many of the problems as possible at once, API Services proposed adding a “jig reference system,” which would allow for the fixture to be built from any position. This reference system would also correct the concentricity of the trunnion centerline, which would eliminate the fixture’s flex issues during rotation, and re-locate the individual locators to match the engineered design of the cargo door to within acceptable tolerances. API Services also provided solutions for adding the design and manufacture of the missing locators to complete the fixture.

Across more than seven weeks of support, API Services was able to create the complete “jig reference system” and include the values (in aircraft coordinates) in a final report to AEI. After working with the concentricity of the trunnion centers, they were able to correct the fixture flex to be within 0.006”, which was acceptable to AEI. They were able to then correct mis-locations of individual locators, setting and pinning in place using steel dowel pins, positioning all locators to 0.010” or less as per engineering design standards. Once all of these corrections had been made, API Services verified the new values of the assembly fixture, assisted AEI with the designs of the lacking fixture locators, and made recommendations to streamline and facilitate the manufacturing process of the cargo door assembly. API provided all locator values, with tolerances, in a complete inspection report as required by AEI.

API Service’s unmatched experience with Aerospace manufacturing and jigs, fixtures, and tooling, combined with their dedicated customer support, allowed them to provide a complete solution for AEI. The team went beyond simple error compensation to create a reference system and best practices to optimize AEI’s work on future door assembly applications. The global team at API Services are the experts in applications across all industries and with API’s world-class metrology equipment. They are standing by to assist your manufacturing needs.