DEVICES capable of reproducing themselves came one step closer to reality this week as a 3D printer 鈥� assembled from parts made by an identical 3D printer 鈥� went on display at the Cheltenham Science Festival in the UK. The replica can in turn print the parts needed to build another copy, and so on.
Technophobes needn鈥檛 run for the hills just yet. The replicating rapid-prototyper, or 鈥淩epRap鈥�, can only reproduce its plastic parts, not its metal or electronic components. And assembling it is an afternoon鈥檚 work for a human being, says Adrian Bowyer, the University of Bath mechanical engineer who launched the RepRap project in 2004.
Despite these limitations, the demonstration represents a watershed for the fast-growing field of desktop fabrication. While 3D printers have become increasingly common, RepRap is the first to be able to reproduce its own components 鈥� and the $600 cost of its off-the-shelf electronics and mechanical parts make it far cheaper than other fabricators.
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The machine is the product of about 100 people around the world who have been working to improve an initial design posted by Bowyer on Reprap.org. The aim of the open-source project is to create a machine that can be used by small communities in the developing world, or hobbyists elsewhere, to manufacture plastic objects of almost any shape. People already 鈥渞un their own CD burners, printing presses and photographic laboratories鈥�, Bowyer points out. 鈥淭here鈥檚 no reason they shouldn鈥檛 run their own factories as well.鈥�
RepRap builds up objects by laying down layers of a plastic that costs about $20 per kilogram. Its products to date range from coat hooks to water-filter inserts and children鈥檚 sandals 鈥� as well as parts for more RepRaps. All the parts for the Cheltenham replica were made by a RepRap owned by Vik Olliver, a systems analyst for Catalyst IT in New Zealand.
RepRap鈥檚 versatility led Chris DiBona, manager of Google鈥檚 open-source team, to call the machine 鈥渁 China on your desktop鈥�.
Work will start later this year on a second-generation machine that can replicate the equivalent of printed-circuit boards to hold electronic chips. The plan is to fill channels in replicated plastic parts with an alloy that melts at low temperatures 鈥� inspired by a 快猫短视频 article describing how engineer John Sargrove cast zinc in Bakelite to make vacuum tube sockets after the second world war. (快猫短视频, 19 October 2002, p 60)
