At the same time that more Sailor and Marines are turning to additive manufacturing to meet readiness challenges, the Naval Air Systems Command (NAVAIR) is beginning to educate its workforce on the potential 3-D printing holds to solve their own problems.
To that end, the Naval Air Warfare Center Aircraft Division (NAWCAD) has launched an initiative aimed at fostering innovation and, as part of it, begun offering introductory, intermediate and advanced “FABLAB Operator” courses on 3-D printing to any interested military personnel and civilians at Naval Air Station (NAS) Patuxent River, Maryland.
The courses are held in a classroom—rebranded the innovation hub or iHub—at NAWCAD’s technical library at NAS Patuxent River. The iHub boasts a row of Ultimaker 2+ printers that are for students and enterprising employees alike—a key aspect of the #NAWCmADe initiative.
Anyone who has taken the introductory course can go to the #NAWCmADe Sharepoint site and reserve time to use the iHub’s 3-D printers, said Ted Delbo, one of the course instructors and a member of NAWCAD’s Strategic Operations and Initiatives Team. Those who have taken the FABLAB Operator”class can use equipment in the initiative’s mobile fabrication lab, or FABLAB, a trailer normally parked outside the library containing large-volume 3-D printers as well as a computer numerical control (CNC) mill, laser cutter and engraver, soldering station, modeling and drafting software, a station for designing circuit boards, and oscilloscopes and microscopes. Those who need help will be connected with an instructor, and Delbo said he meets anyone who signs up to use the workspaces at the library to get them set up.
As of mid-February, 230 people had taken one of the classes, and 18 projects had been completed using the #NAWCmADe facilities.
The initiative has already produced results. When Chuck Stouffer, an aerospace engineer with NAWCAD’s Propulsion and Power Engineering Department, discovered the FABLAB’s large 3-D printers during a three-day open house last June, he knew he could use them to solve a nagging problem the F/A-18E-F Super Hornet fleet was experiencing with the air vents on the jet’s vertical stabilizers.
The vents allow ram air to pressurize the fuel tanks during flight. Every couple weeks aboard the Navy’s aircraft carriers, when the aircraft are washed to prevent corrosion from saltwater, the vents must be covered to keep water from getting into the fuel tanks. Currently, Sailors and Marines use a crane and cover the vents with speed tape, a pressure-sensitive aluminum tape used to make minor, temporary repairs to aircraft and race cars.
Looking for a quicker and better solution, the fleet asked Stouffer if his department could design a wash cover for the vents. Stouffer used computer-aided design (CAD) software to design a cover, which #NAWCmADe team member David Hamm optimized for 3-D printing. An oversized, proof-of-concept prototype finished printing in roughly 96 hours.
The design was sent to the F/A-18 Fleet Support Team (FST) at Fleet Readiness Center Southwest (FRCSW) in San Diego, which modified some dimensions and produced a second prototype that fit the actual aircraft vent. Three months after Stouffer attended the open house, the second prototype had been printed back at the FABLAB and shipped to the fleet to be threaded onto a 15-foot wash stick and applied to a Super Hornet vent. Fleet feedback will be incorporated into a final design, which will then be sent to the FST at FRCSW to be mass produced either in-house or by a commercial manufacturer.
In another success story, Stouffer was involved in an effort to mitigate contamination of the Super Hornet engine’s variable exhaust nozzle (VEN) actuator due to water coming through the air vents.
Some of the actuators were sent to have their internal gears studied by NASA at the Marshall Space Flight Center in Huntsville, Alabama. But NASA could not disassemble the actuators because of a hard-to-reach sync nut that required special tooling to remove.
So, while taking one of the introductory 3-D printing courses, Stouffer designed and printed out a T-shaped tool designed to reach inside the actuator and remove the nut with no need for disassembly.
Stouffer tested the “T-Handle” tool and sent its data file to NASA the next morning, where researchers were able to print the tool out in less time than it would have taken to ship to Huntsville.
“It’s a feel-good project, where you found a solution really inexpensively and were really innovative and quick,” Delbo said.
Nothing so grand came out of my class, during which each student used CAD software to design a plastic keychain and coin. Once each design was completed, the CAD files were imported into a “slicing” program, which converts design files into code read by the 3-D printer.
Among the lessons I learned during the class:
- In the slicer program, you can set your object’s “infill,” or fill density. For instance, if you set the infill to zero percent, your part will be hollow. Set the infill to 100 percent, and the part will be solid. Generally speaking, 20 percent infill is considered a healthy median between weight, cost and strength.
- Anything less than 100 percent infill manifests in a grid-like pattern, the shape of which can be customized. You can make your grid out of hexagons, squares, or even honeycomb, among other patterns. Apparently, according to class instructor Russell Gilbert, a MakerBot printer can replace your boring infill pattern with one in the shape of cats. It’s called “catfill,” in case you were curious.
- If there is a problem with a print, it’s probably due to the build plate not being level. Gilbert estimates that 90 percent of botched prints stem from build plate level.
At the end of the class, I walked away with a rounded orange keychain reading “Naval Aviation News” and a blue “coin” in the shape of Darth Vader’s helmet. More importantly, I felt comfortable with the process of designing basic objects in CAD software and exporting them to a 3-D printer. Delbo said it is this kind of learning, more so than the actual projects, that represents the real benefit of an initiative like #NAWCmADe.
“The 3-D printing classes are an excellent opportunity for engineers to learn how to take advantage of additive manufacturing for their work,” said Nick Makrakis, a physicist in NAWCAD’s Avionics, Sensors and Electronic Warfare Department. “You can go from little to no CAD knowledge to designing and printing prototypes very quickly.”
A test pilot with Air Test and Evaluation Squadron (VX) 23, Lt. Ian Higgins said he signed up for the introductory class to familiarize himself with an emerging technology. According to him, he left the class with a “fundamental understanding of the 3-D printing process.”
“I know it’s state-of-the-art stuff that we’re going to be using in the future,” he added. “I don’t see it going away. It’s fantastic that NAWCAD provides this course. This shows they’re looking for that leading edge that’s going to allow us to develop future technologies.”
Written by Jeff Newman, a staff writer for Naval Aviation News.