According to Robert Kestler, science and technology
lead for research and engineering at FRC East in Cherry
Point, N.C., the center uses FDM to produce tooling for
sheet metal manufacturing and composite repair.
“FDM is like a glue gun on steroids. High-strength
polymer material is fed from a canister like a line from a
Weed Eater into a machine, where it’s heated, then applied
with a nozzle in an extrusion process layer by layer,”
Kestler said. “We can then create a shape that will be used
to press the sheet metal onto that shape to create the part.
“It can also be used to make a template for composite
repair. We can scan a damaged area, develop tooling and
form the composite layup to create the patch. Something
that might normally take five steps, we proved we could
do it in one step using the polymer tool,” he said.
A 3D printer can be as small as a desktop printer, or
large enough to make a 5-foot, single-piece scale model
of an aircraft carrier.
Nine commands within the Naval Sea Systems
Command Warfare Centers are applying 3D printing
technology. NSWC Crane Division, Ind., is using 3D
printers in support of the special warfare and expeditionary warfare communities to rapidly develop prototypes for the design and development of weapons, sensors and visual augmentation systems. NSWC Dahlgren Division, Va., is using 3D printers to produce mechanical parts in support of gun design efforts.
Stereo lithography has been used by the NSWCCD for
more than 10 years to make scale models of ships and
functional parts. It uses a vat of photo-curing resin and a
laser, according to Josh Crum, rapid prototyping supervisor supporting the Model Fabrication Facility.
Following the CAD drawings, the object is created by
using the laser to trace the pattern and illuminate the
resin, causing it to harden. The object is then lowered by
a fraction of an inch, coated with fresh resin and the next
“layer” is hit with the laser, solidifying more of the resin.
When all the layers are complete, the resin is wiped
off and the object placed in ultraviolet light chamber
— something akin to a tanning bed — to give it a UV
bath that cures the resin, Crum said.
Earlier this year, Carderock fabricated a scale model of
the hospital ship USNS Comfort (T-AH 20) from CAD
drawings using a 3D printer. The model was used in
Carderock’s Anechoic Flow Facility wind tunnel to determine the aerodynamic and acoustic properties of the
superstructure, and the effects of different relative flight
deck wind conditions for safe aircraft operations.
“The model of the T-AH 20 was created within 25
days,” said NSWCCD engineer Francisco “Paco” Rod-riguez.
Before they had the 3D printer, he said, it would
have required twice the time to conduct four different
builds in the older, smaller machine, followed by putting all of the parts together.
“Carderock engineers have been building and testing
Navy ship models for more than 100 years,” Crum said.
“This next-generation technology provides Carderock
unprecedented capability to deliver fabricated ship mod-
els faster and at a more affordable cost for the Navy.”
There also is the cost of the raw materials going into the
part and the energy to make it. However, instead of
machining down to a part that is 10 percent of the original
billet, generating 90 percent waste, you can just use what
you need. Laser-built parts use powder, so there’s still pow-
der that needs to be blown out after the part is completed.
“The unused powder can be reused,” said Caroline
Scheck, a mechanical engineer at NSWCCD.
That’s important, Wolk said, because for some met-
als, like titanium, “powder is pricey. There’s still some
post-processing, but not the same level as with other
Reverse engineering also is simplified.
“If the drawing no longer exists, we can scan it to
get a 3D CAD model,” said Scheck.
It is possible to embed electronics within the various
layers of an AM object. Working with unmanned aerial
vehicle (UAV) manufacturer Aurora Flight Sciences,
Manassas, Va., Albuquerque, N.M.-based Optomec has
Jennifer Wolk, a materials engineer at Naval Surface Warfare Center Carderock Division, Bethesda, Md., is
researching nonferrous naval materials, such as aluminum
and titanium, in particular, the area of microstructural evolution of these materials due to joining. She also works in
advanced manufacturing processes, such as friction stir
welding, cold spray and additive manufacturing.