SAN DIEGO, Calif. --- Space and Naval Warfare Systems Command (SPAWAR) Enterprise experts in three-dimensional scanning and printing rapidly developed and delivered an effective and reliable solution to repair a critical piece of warfighting equipment, the AN/TRC-194 antenna, with the final of three upgrades delivered August 31.
From 2015 to 2017, failures of the azimuth antenna drive occurred due to rainwater intrusion. Repairing the antenna with existing parts was not a viable solution as the original antenna pedestal was built in 1988, and the parts were no longer available. Additionally, the antenna pedestal was built utilizing a sand-casting technique. The original cast no longer exists, and it would be cost prohibitive to determine the geometry of the antenna’s parts without the cast.
To protect the azimuth antenna drive from future rainwater intrusion, SPAWAR System Center Pacific’s (SSC Pacific’s) Reverse Engineering – Science and Technology for Obsolescence, Restoration and Evaluation (RESTORE) lab teamed with the Program Executive Office for Command, Control, Communications, Computers and Intelligence’s (PEO C4I’s) Undersea Communications and Integration Program Office (PMW 770) to develop a new agile and robust cover utilizing 3D scanning and printing technology.
“The RESTORE lab is a reverse engineering laboratory which uses a process that identifies a target obsolescence issue in a legacy system—usually a single-point-of-failure component or assembly—and creates a modern form, fit and function replacement, to support life-cycle-extension programs for legacy systems,” said Stephen Cox, chief engineer for the RESTORE lab.
Beginning in June 2017, SSC Pacific’s RESTORE lab collaborated with PMW 770 in an effort to scan the entire antenna using a 3D laser scanner. By October 2017, the data was converted to create a working computer-aided design (CAD) model capable of articulating through the full antenna range of motion, while being accurate to a thousandth of an inch.
“Scanning the entire system allows us to create a blueprint that our engineers can reference when fabricating a solution,” said Cox.
Several azimuth antenna designs were created and tested within the CAD model. A two-piece, "armadillo-like," nested-shell design was selected, and the components were additively manufactured on a 3D printer. The total process time from scanning to printing the prototype solution was approximately six months.
This process of scanning a system, creating a CAD model and fabricating a solution was coined by Cox as the scan-to-CAD-to-fab method.
“The scan-to-CAD-to-cab method lowers the cost and increases the speed at which a unique product can be made,” said Cox. “It also facilitates rapid changes and the product becomes better, faster, with each engineering cycle.”
In recent years there has been an increased need for this innovative process. Most recently, the United States Air Force has been in contact with SPAWAR to discuss applications of this technique for its own purposes.
SPAWAR identifies, develops, delivers and sustains information warfighting capabilities supporting naval, joint, coalition and other national missions. SPAWAR consists of more than 10,000 active duty military and civil service professionals located around the world and close to the fleet to keep SPAWAR at the forefront of research, engineering and acquisition to provide and sustain information warfare capabilities to the fleet.