An aircraft made entirely by a 3D printer takes flight

Engineers at the University of Southampton have designed and flown the world's first 'printed' aircraft, which could revolutionise the economics of aircraft design.

The SULSA (Southampton University Laser Sintered Aircraft) plane is an unmanned air vehicle (UAV) whose entire structure has been printed, including wings, integral control surfaces and access hatches.

It was printed on an EOS EOSINT P730 nylon laser sintering machine, which fabricates plastic or metal objects, building up the item layer by layer. No fasteners were used and all equipment was attached using 'snap fit' techniques so that the entire aircraft can be put together without tools in minutes.

The project team worked in partnership with  additive manufacturing market leader 3T RPD, which specialises in  producing lightweight, high performance plastic and metal parts that are unachievable by traditional manufacturing techniques.

3T RPD undertook the manufacture and detailing of the design, as well as supplying laser sintering knowledge and expertise.

The electric-powered aircraft, with a 2-metres wingspan, has a top speed of nearly 100 miles per hour, and is almost silent in cruise mode. The aircraft is also equipped with a miniature autopilot developed by Dr Matt Bennett, one of the members of the team.

Laser sintering allows the designer to create shapes and structures that would normally involve costly traditional manufacturing techniques.

This technology allows a highly-tailored aircraft to be developed from concept to first flight in days. Using conventional materials and manufacturing techniques, such as composites, this would normally take months.

Furthermore, because no tooling is required for manufacture, radical changes to the shape and scale of the aircraft can be made with no extra cost.

This project has been led by Professors Andy Keane and Jim Scanlan from the University's Computational Engineering and Design Research group.

Professor Scanlan says, ''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. One of these ideas involves the use of a Geodetic structure. This type of structure was initially developed by Barnes Wallis and famously used on the Vickers Wellington bomber which first flew in 1936. This form of structure is very stiff and lightweight, but very complex. If it was manufactured conventionally it would require a large number of individually tailored parts that would have to be bonded or fastened at great expense.''

Professor Keane adds, ''Another design benefit that laser sintering provides is the use of an elliptical wing planform. Aerodynamicists have, for decades, known that elliptical wings offer drag benefits. The Spitfire wing was recognised as an extremely efficient design but it was notoriously difficult and expensive to manufacture. Again laser sintering removes the manufacturing constraint associated with shape complexity and in the SULSA aircraft there is no cost penalty in using an elliptical shape.''

3D printing
Three-dimensional printing, the technology which enables complex components to be built up layer by layer, has been around for two decades. Initially, its primary application was product prototyping. But as technology and quality have improved, costs have plummeted; today, the manufacturing world stands at the dawn of a new era.

Why does it move the game on?

3D printing sidesteps the need for conventional tooling (which can take months) by sending a three-dimensional design directly from the computer to a specialised 'printer' - a laser assisted fabrication machine - which builds it up layer by layer. Wastage is minimised, production lead times are a fraction of their conventional equivalent - and therefore, costs are dramatically reduced. Even more exciting is the ability to produce bespoke designs at minimal extra cost.

This has particular significance to rarefied industries like Formula One, and is increasingly used in medicine. In the years to come, customised implants and other replacement body parts will become the norm, fabricated on the spot by hospital-based 3D printers. Because the process is so flexible, designs that would be prohibitively expensive to make conventionally can be produced to exceptional tolerances.

Because 3D printing involves no cutting or grinding of metal, its potential knows virtually no bounds. Arguably, it's limited only by the ingenuity of the world's industrial and product designers.

Aerospace design
Exploiting airflow over surfaces - whether to produce lift in an aircraft or downforce in a racing car - is a complex process which until recently, has been limited by conventional manufacturing techniques. For instance, prewar aircraft designers knew that an elliptical wing was the most efficient blend of lift and low drag, as epitomised by the ultra-fast, ultra-manoeuvrable Supermarine Spitfire.

But it was hideously expensive and complex to build; in the last half-century, many designs have gone no further than the drawing-board for this reason.

But with the advent of 3D printing, those designs are being revisited - which could bring about a revolution in the aviation industry. At a time of economic uncertainty and soaring fuel costs, it couldn't be better timed.

And with their historic flight of the world's first printed aircraft, Southampton's researchers are leading the way.