The RoboHand device can be easily redesigned and refitted as children grow. Image: MakerBot
Forged through the mixing of high-tech fabrication and old-fashioned mechanical tinkering, a carpenter and a self-described “mechanical effects artist” have combined efforts to provide low-cost, low-tech mechanical fingers for those people lacking them. Called RoboHand, the device is made of thermosplastic fabricated on a 3-D printer and operated using what is basically a pulley-and-cable system.
Its inventors, South African carpenter Richard Van As and Ivan Owen, from Bellevue, WA, have fitted about 170 people, many of them children, with a RoboHand since they began mastering 3-D printing at the beginning of this year. The inventors have produced them at cost, paid for through donations, allowing clients to avoid paying thousands of dollars for prosthetics such as a myoelectric hand, which works using a muscle’s electric impulse to move an artificial limb.
The venture began two years ago after Van As lost four fingers while working with a circular saw. While recovering, he started searching for a low-cost prosthesis and, finding nothing that really fit his needs or his wallet, decided to build one himself. That’s when he discovered Owen.
“I had built this silly oversized puppet hand” and put a video of it on the Internet, says Owen. “Rich saw it…and wanted to collaborate on a design for a partial finger replacement. It was kind of a stream of consciousness effect of the Internet.”
RoboHand is fabricated with thermoplastic through 3-D printing. Image: MakerBot
Van As grabbed Owens’ interest and the two began a very long-distance collaboration. They initially worked with lightweight metals, often from sketches drawn by Van As. Owens would offer suggestions and Van As would attempt to build them in his shop. “We explored a lot of different designs,” says Owens. “There’s actually a lot [of information] out there. It’s basically a cable-and-pulley mechanism from a puppeteering hand.”
While researching a range of anatomy from human fingers to crab legs, Owens says they came upon the Hand of Corporal John Coles, a similar device made in Australia in the early 19th Century of whalebone. Coles blew most of his fingers off while priming cannon, and a local physician built the prosthesis for him. It works by strings that are activated by the thumb.
But whalebone certainly is not practical, and even metal, while sturdy and long-lasting, is expensive. In December 2012, Owens says a co-worker suggested he look at 3-D printing as a potential method of reducing costs.
“We were operating without a budget,” says Owens. “Our work had been funded by crowdsourcing online. I wasn’t even aware there was a consumer-level 3-D printer available.”
Call for Help
In December 2012, the two approached 3-D printing pioneer MakerBot, looking for help. Company officials, recognizing the humanitarian goals of the research, jumped in and donated a MakerBot printer to each of them.
“They were having a difficult time,” says Jenifer Howard, a MakerBot spokesperson. “They were trying different materials and techniques, but there was no consistent product. We moved pretty quickly, and we had not done anything like this before. They received a printer each in January and in two weeks had a fully functioning RoboHand.”
Ivan Owen is one of RoboHand’s developers. Image: MakerBot
“The results have been huge,” says Owens, noting that the great distance between himself in Washington and Van As in South Africa complicated design and fabrication, even with the Internet. “To make a prototype, and have to mail it back and forth could cost several hundred dollars and three weeks in the mail,” he says. With the printer, they could work virtually together and hold copies of the same object in real time.
Owens, who is not an engineer and has no formal training in design, says the 3-D printing learning curve “was not as steep as you might have imagined.” He has always been mechanically inclined and gained experience working as an industrial technician in previous jobs. Working with OpenSCAD software and the printer, he says he was able to code a simple mechanical system within a week.
What began as a project to help Van As regain function as a tradesman has morphed into an operation that is changing people’s lives, especially those of children. After posting his story online, parents whose children were missing fingers began contacting him, asking if he could do anything to help them. He did, fitting and fabricating for no cost.
Cheap and Easily Replaced
Many of the children suffer from Amniotic Band Syndrom, a condition that prevents the growth of extremities, primarily fingers and toes, in the womb. Some 80% of such cases involve the loss or malformation of hands and fingers. 3-D printing has given these kids and others a fast and cost-effective option. Prostheses now available are prohibitively expensive for most people, especially for children who outgrow them quickly and must be refit.
“The really big thing is the ability to rescale and reprint,” says Owen, who left the operation earlier this year. “Plastic doesn’t last as long [as metal or wood] but it doesn’t have to. It is easy to rescale a project once it has been designed.”
Because the two never intended RoboHand to be a service or product, Van As made design files and instructions available on Thingiverse for anyone to design and print themselves. Howard says the device can be produced for about $150 although Owen says one family contacted him to say they fabricated a RoboHand for only $50.
Owen says most anyone with access to a 3-D printer, even if not especially mechanically inclined, can produce one. Howard says design files and instructions have been downloaded over 30,000 times already.
“This can change so many lives for the positive,” she says.
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The really big thing is the ability to rescale and reprint. It is easy to rescale a project once it has been designed.