Scott Sevcik
The US Air Force has spent the last 70 years launching aircraft, rockets, and satellites, but this week, they launched something really unique – the Advanced Manufacturing Olympics. The USAF set aside a million dollars in prize money and then asked industry to compete on six different technical challenges. The goal is to create an opportunity for the USAF to find new and innovative ways to support aging aircraft faster and with less expense by utilizing new technologies.

Stratasys was privileged to participate in three of the six technical challenges. Lockheed Martin invited us to join their team for the Box of Parts, and we fielded Stratasys-led teams for the Supply Chain Marathon and F-16 Approval Sprints.

Supply Chain Marathon

We were excited to learn that we received the Silver Medal in the Supply Chain Marathon. In this challenge, we were given a scenario and asked to prepare a strategy to support warfighters in the field using advanced manufacturing. We described an approach where we deployed containerized production facilities with 3D printers and CNCs in the field with reach back to graduating levels of manufacturing capability both in-region, and back in the US. This strategy was informed by our own experience managing the logistics of rapid part production at our Stratasys Direct Manufacturing facilities where we produce more than 30,000 flight parts per year across nine different additive and traditional technologies. Our strategy focused on maximum flexibility for the warfighter, as well as realism. Whereas the USAF gave us a 3-year horizon, we focused on capabilities that could be delivered to the warfighter today.

F-16 approval sprints.

At the end of the week, what many would consider the capstone event, the F-16 Approval Sprint was unveiled. For this challenge, the USAF provided an example of a family of hydroclamps used on the F-16. They selected one part for a physical demonstration and asked us to produce a strategy for rapid qualification of the entire part family. With the extreme rigor required to flight-qualify replacement parts, how can the USAF utilize advanced manufacturing technologies effectively by accelerating not only the production, but also the qualification of the approval process?

For the physical demonstration, Stratasys surveyed the range of additive manufacturing technologies and selected a flame-retardant Laser Sintered Nylon 11 and the FDM® Antero material as the two best options for meeting the requirements. We ultimately selected FDM Antero due to the unmatched chemical resistance of PEKK and Antero’s strength and performance repeatability. Because we didn’t have the loading requirements, we tested parts built with both technologies and materials and selected the lowest-risk/highest-strength part. We also initially evaluated a variety of design changes to further reduce part weight, but decided to go with an un-redesigned part for two reasons: 1) Maintain maximum strength due to unknown loading requirements, and 2) Simplify qualification by not introducing a new design and limiting change only to material and process.

While our part was not selected to fly, we couldn’t be more excited to see that another part designed by the National Institute of Aviation Research, made it onto the F-16 that also featured the Antero 800NA material!
FDM Antero Compare.
Multiple design iterations of the Antero-based F-16 hydroclamp.
As much as the physical demonstration was a significant test, the biggest challenge was to describe a strategy for quickly qualifying an entire family of parts. To do this, we built on what we started with the physical demo. We determined that the fluid susceptibility requirements for the part family required Antero’s chemical resistance or secondary processing of a FR-Nylon part, so for simplicity, we again selected Antero. Also building on the difficult decision not to change the design for the demo, we again decided that the fastest path to qualification was to stay with the existing design, rather than redesign for additive.

In many ways, the decision to not change the part design is incredibly difficult. One of the key advantages of additive manufacturing is the ability to use less mass and optimize parts. While we firmly stand behind this benefit, particularly in new design scenarios, sustainment can be different. When the goal is to quickly replace a traditionally manufactured part, the lowest-risk path to qualification is to minimize change. With Antero, we are able to introduce a highly robust material and process replacement but aren’t forced to change the part design. There is opportunity in design change, but also effort and risk. With decision criteria geared toward fast qualification, opening the design space is not the most efficient path in this case.
Dr. Will Roper, Assistant Secretary of the Air Force for Acquisition, Technology and Logistics, showing an ULTEM(TM) 9085 C-5 latrine cover panel that clued him into the value of additive manufacturing, during the AM Olympics presentations.

To achieve the most efficient path to qualification, Stratasys proposed pre-work. Through the America Makes/NIAR qualification project that yielded a highly repeatable F900™ 3D printer with ULTEM™ 9085, we’ve demonstrated the value of having publicly available characterization data. We recommend more projects in a similar vein – perform public qualifications on relevant materials and processes in order to build a reference toolbox to quickly deploy those properties on replacement part qualifications. In addition, we recommend continued investment in tools like Digimat that can accurately model 3D printed parts.

With reference information and robust tools, and by resisting the urge to redesign the part for additive manufacturing, qualification can be reduced to only the tests and analysis that are unique to the specific part or part family. This is how we sprint for approval, and we’re proud to say the USAF agreed. We took a Silver medal in this challenge as well!

And the most impressive part, in my mind, is the fact that the USAF gave us a month to come up with a demo part, and three weeks after we delivered parts, an Antero 800NA part flew on an F-16. Imagine what we can do with robust data sets and tools already in place!