Fabber unlocks home prototyping

Hod Lipson, Cornell assistant professor of mechanical and aerospace engineering, has developed Fab@Home, a machine that replicates objects from plans supplied by a computer.

Fab@Home, or fabber, could change how consumers acquire common products, suggested Lipson. Instead of buying an iPod, the consumer would download the plans over the internet and the fabber would make one.

Such machines could evolve from the 3D printers currently used by industrial engineers for rapid prototyping. They design parts in computer-aided design programs and feed the designs to 3D printers to make working plastic models. A 3D printer has a small nozzle that scans back and forth across a surface, depositing tiny droplets of quick-hardening plastic. After each scan, the nozzle moves up a notch and scans again until it has built up the complete object, layer by layer. With multiple nozzles or a means of swapping supply cartridges, the machine can create objects made of many different materials. An electronic circuit, for example, can be made by combining an organic semiconductor, metallic inks and ceramic insulators.

Price tags for these machines average around $100,000, but Fab@Home can be built for about $2,300 worth of off-the-shelf parts. The prototype, designed by Evan Malone, a Ph.D. candidate in Lipson’s Computational Synthesis Laboratory, is slower than the commercial models, and its resolution, or ability or produce fine detail is lower, but people are finding practical — and often unexpected — uses for it.

Commercial machines can not be modified, which, Lipson said, impedes the progress of the technology, but the Fab@Home is “open source.” Anyone can download the plans at http://www.fabathome.org. The site also includes construction hints, ideas for applications, notes on the history of 3D printing and discussion groups.

So far, Lipson said, about a dozen people have said they are building one, and he knows of three that are actually up and running — two at the University of Washington and one in Innsbruck, Austria. Lipson’s group has built several and lent a couple to other researchers.

Future fabbing machines will have to shift from one raw material to another in midstream and probably deposit material in three dimensions, not just layers, said Lipson. Research in his lab is taking early steps. Malone has built a machine that uses a rack of interchangeable cartridges to make devices out of several materials at once. So far, it has made a working battery, complete with outer case. Malone’s long-range goal is to “print” a complete robot, including limbs, actuators, control circuitry and batteries.