U.S.-Israeli additive manufacturing specialist Stratasys will be exhibiting an all-new, one-off, “printed” UAV here at the Dubai Air Show this week, along with a video of the aircraft’s first flight. The only thing that isn’t printed using “additive manufacturing” technology is the small turbojet engine and its electronics and servos.
Stratasys is exhibiting at “3D Printshow Dubai,” a dedicated pavilion here at the show. It is presenting alongside other exhibitors, including Ultimaker, BigRep and Stratasys Platinum Partner, D2M Solutions (Stand 206).
Scott Sevcik, Stratasys senior manager business development, aerospace and defense, told AIN in late October that the project was to be revealed for the first time here at the show.
“We are debuting on our booth a large printed UAV,” he said, “We have worked with Aurora Flight Sciences…it’s about three meters [10 feet] in wing span and can fly at 150 mph [130 kts]. It has already flown, in August, from the salt flats in Utah. It’s big, fast and almost entirely printed.” He admitted the aircraft doesn’t have a name yet: “We just call it ‘The Printed Aircraft.’”
There is no carbon-fiber layup used in the airframe construction and the control surfaces have been “printed” also, as has the landing gear and engine duct (both from metal). “It is about 80 percent printed, by weight,” said Sevcik. The structure/airframe was printed using an FDM (Fused Deposition Modeling) process and some parts were created using laser sintering, he added. The latter include the fuel tank and winglets.
Sevcik said that all the materials used are commercially available; for the Ultem, 1010 was used, and “several other” materials; while ASA (which is UV-resistant) makes up the fuselage elements. Laser-sintered nylon was used for the fuel tank and Inconel for the engine duct.
The project was started in the first quarter of 2015, said Sevcik. “We went from a suggestion to flying in a little under eight months,” he said. It was a very small team–all in-house (everything was printed by Stratasys) though the engine, a small turbojet, and electronics came from third-party suppliers.
Sevcik said “I don’t have hard numbers [for production costs] but the period concept-to-flight was well under a year,” which he said illustrated that significant costs could be saved on such a project. Design was carried out using Dassault Systèmes SolidWorks and GrabCAD at the collaborative platform, which Aurora used so the engineers could work together in design.
Stratasys used its own internal software for the printing processes, including Insight. This prepares the CAD program’s STL output for 3D manufacturing on a Fortus machine “by automatically slicing and generating support structures and material extrusion paths,’ said the company. Sevcik said Stratasys also used a third-party U.S. company to help optimize the structure weight, based on loads. He said, “They used the loads to calculate how little material you can use,” with safety margins.
So why is Stratasys at the Dubai Air Show? “We’re hoping to highlight it more as a capability to build lightweight structures of this class, and to really show the industry that the concepts are directly applicable to larger-scale vehicles.
Sevcik said that the company has “quite a bit going on in aerospace,” for example United Launch Alliance is using Stratasys 3D printing technology (using FDM thermoplastic ULTEM 9085), for parts in environmental control system ducts, “slashing the system’s production cost by 57 percent and reducing the ECS assembly from over 140 to just 16 production parts.”
Meanwhile Airbus has used Stratasys printed parts to swap out heavier, non-load-bearing parts in the Airbus A350. Sevcik said the UAV project demonstrated that 3D printing could be used to create load-bearing structures, too.