They resemble microwave ovens but, in fact, are 3D printers that not only make jewellery, toothbrushes, complex machine components and medical implants, but football boots, racing-car parts and custom-designed cakes come alive. But can you imagine them emulating the Wright brothers and printing an aircraft?
Engineers at the University of Southampton have achieved precisely this. According to an institute release, the engineers have designed and flown the world’s first ‘printed’ aircraft, "which could revolutionise the economics of aircraft design”.
The Southampton University Laser Sintered Aircraft (SULSA) plane is an unmanned aerial vehicle (UAV) whose entire structure has been printed, including the wings, integral control surfaces and access hatches. SULSA is part of the EPSRC-funded DECODE project, which is employing the use of manufacturing techniques such as laser sintering, to demonstrate their use in the design of UAVs.
The aircraft was printed on an EOS EOSINT P730 nylon laser sintering machine, which fabricates plastic or metal objects, building the item layer by layer. No fasteners were used and all equipment were attached using ‘snap fit’ techniques so that the aircraft could be put together without tools in minutes. The electric-powered aircraft, with a two-metre wingspan, has a top speed of nearly 100 miles per hour. However, it's almost silent when in cruise mode, said the release. The aircraft is also equipped with a miniature autopilot developed by Matt Bennett, one of the team members.
Laser sintering allows the designer to create shapes and structures that would normally involve expensive traditional manufacturing techniques. The 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 manufacturing, radical changes to the shape and scale of the aircraft can be made at no extra cost. The project has been led by Professors Andy Keane and Jim Scanlan from the University’s Computational Engineering and Design Research group.
Fabbers, or personal manufacturing machines (3D printers come under this category), are expected to change the way we live. Engineers and designers have been using 3D printers for more than a decade, but mostly to make prototypes quickly and cheap. In India, DesignTech Systems, a distributor of Stratasys Inc, had launched uPrint – a personal 3D printer – priced at $14,900 in June 2009. Wohlers research suggests that over 20 per cent of 3D printers’ output are now final products rather than prototypes and the figure is expected to rise to 50 per cent by 2020.
3D printers fabricate complex objects by depositing materials, layer by layer. They use an additive process (make objects by systematically depositing a chosen raw material in layers). The most common household 3D printing process involves a ‘print head’ that works with any material that can be extruded or squirted through a nozzle.
Another common type uses a laser beam or glue to selectively fuse powdered plastic, metal or ceramic in layers.
A user can select an electronic design blueprint and load the raw materials into the 3D printer. The machine does the rest. In a process that can take several hours to days.
At Cornell University, for instance, engineering students with no culinary training used their lab’s 3D printer to fabricate custom-designed cakes which, when cut open, revealed a letter ‘C’. Cornell’s 3D food printer isn’t commercially available as yet.
3D printers typically use plastic, but some high-end machines are able to work with metals and ceramics too. Known as personal manufacturing machines or ‘fabbers’, industrial-size 3D printers cost up to half-a-million dollars, while low-end personal-scale 3D printers cost less than $1,000. Today’s lowest-cost 3D printers have their roots in the University of Bath’s 3D printer called RepRap and Cornell’s Fab@Home project. The blueprints for both are available free to anyone who wants to build his/her own machine or improve upon existing designs — even commercially.
Hod Lipson, an associate professor at Cornell University, who authored a report commissioned by the US Office of Science and Technology Policy titled Factory@Home, told reporters at the American Association for the Advancement of Science (AAAS) event held in Washington DC early this year: “People with no special training can rip, mix and burn physical objects like custom machine parts, household goods, jewellery, and maybe someday, electronic devices.”
Going forward, lack of human imagination appears to be the only limitation for 3D printers. The Fab@Home team at Cornell, for instance, is pursuing the ability to manufacture, on a single 3D printer machine in a single “print job” — a robot. Lipson tickles one’s imagination with his vision of an “...assembly line of computer-guided, 3D printers giving ‘birth’ to baby robots that crawl out of the printer and wander off to a nearby nursery where they learn to use their arms and legs according to instructions already hard-wired into their electronic circuitry.”
NASA is exploring the role of 3D printers as an integral tool for space exploration missions to manufacture machines that can print their own replacement parts and are versatile enough to use a wide variety of materials available on site. The factories of the future, meanwhile, are expected to have 3D printers working alongside milling machines, presses, foundries and plastic injection-moulding equipment.
In the US, universities, including Standford, Massachusetts Institute of Technology (MIT) and Cornell, have integrated personal fabrication technologies into their science and engineering curricula. The Defense Advanced Research Projects Agency (DARPA), too, has launched a Manufacturing Experimentation and Outreach (MENTOR) initiative to deploy digital manufacturing equipment, including 3D printers, in public high schools.
