SOUTHAMPTON, U.K.—Engineers at the University of Southampton have designed and flown the world’s first “printed” aircraft, built using a rapid prototyping technique known as selective laser sintering (SLS).
The Southampton University Laser Sintered Aircraft (SULSA) plane is an unmanned autonomous vehicle (UAV) whose entire structure has been printed on a EOS EOSINT P730 nylon laser sintering machine, which makes plastic or metal objects by building them up layer by layer.
All of the plane’s components are attached using snap-fit techniques so the entire aircraft can be put together without tools.
The electric-powered aircraft has a two-metre wingspan and a top speed of nearly 160 km/h, but is almost silent in cruise mode.
Laser sintering allows designers to create shapes and structures that would normally involve costly traditional manufacturing techniques and materials.
Because no tooling is required, changes to the shape and scale of the aircraft can be easily made.
The aircraft was built on a lattice-type structure, only visible when components are held to a light, says Terry Wohler, president of Wohler Associates, a consulting firm specializing in trends in rapid product development and additive manufacturing.
“That lattice structure is how you create very strong, lightweight parts using laser sintering,” he says.
Wohler says a number of firms are increasingly using laser sintering and rapid prototyping technologies for parts, but not in huge amounts – think volumes in the hundreds. Aerospace firms Boeing and Airbus have developed more than 20,000 laser sintered parts without a single failure.
The majority of them are air ducts or environmental control ducting that directs air flow to cool different parts of the plane, Wohler says.
He says mass-produced laser sintered components may not be in the near future, but companies will focus these technologies on lower volume, high valued products.
“Using traditional techniques, manufacturers would use 35 parts per component, but with laser sintering they can do it in one or two pieces, reducing the time and inventory, resulting in components that can be built on demand,” he says. “But, mass production isn’t a good fit for this technology – it’s better for building relatively small, difficult to manufacture parts.”
The project has been led by Professors Andy Keane and Jim Scanlan from the University’s Computational Engineering and Design Research group.
“The flexibility of the laser sintering process allows the design team to re-visit historical techniques and ideas that would have been prohibitively expensive using conventional manufacturing,” says Scanlan.
SULSA is part of the EPSRC-funded DECODE project, which employs the use of leading edge manufacturing techniques, such as laser sintering, to demonstrate their use in the design of UAVs.
The University of Southampton has been working in UAV development since the early 1990s when work began on the Autosub programme at its waterfront campus at the National Oceanography Centre, Southampton. A battery powered submarine travelled under sea ice in more than 300 voyages to map the North Sea and assess herring stocks.
Watch the 3D-printed plane take its maiden voyage: