A parallel Worlds

Sunday March 6 2011 / Science & Technology

Printing, even 3-D printing, isn't the sexiest of topics; however, recent advances in technology have opened up an incredible range of possibilities. Producing solid objects, even quite complex ones, with 3-D printers is gradually becoming easier and cheaper. Some predict that it will not be too long before such devices are as widespread as document printers?

                                      Apparently it plays well

At the moment the process is possible only with certain materials (plastics, resins and metals) and with a precision of around a tenth of a millimetre. As with computing in the late 1970s, it is currently the preserve of hobbyists and workers in a few academic and industrial niches. But like computing before it, 3D printing is spreading fast as the technology improves and costs fall. A basic 3D printer, also known as a fabricator or “fabber”, now costs less than a laser printer did in 1985.

Some of these printers are becoming small enough to be desktop devices. They are making their way not just into workshops and factories, but also into the offices of designers, architects and researchers, and are being embraced by entrepreneurs who are using them to invent entirely new businesses.

It works like this: first you design the object to be printed on your computer . . . and then you press 'Print'. A 3D printer gradually builds up the object, either by depositing material from a nozzle, or by selectively solidifying a thin layer of plastic or metal dust using tiny drops of glue or a tightly focused beam. Products are built up by progressively adding material, one layer at a time, which is while the  technology is also referred to as, additive manufacturing. Eventually the object in question—a spare part for your car, a lampshade, a violin—pops out.

This additive approach to manufacturing has several major advantages over conventional techniques. It cuts costs by eliminating production lines. It reduces waste enormously, requiring as little as one-tenth of the amount of material. It allows the creation of parts in shapes that conventional techniques cannot achieve, resulting in new, much more efficient designs in aircraft wings or heat exchangers, for example. It enables the production of a single item quickly and cheaply—and then another one after the design has been refined.

For many years 3D printers were used in this way for prototyping, mainly in the aerospace, medical and automotive industries. Once a design was finalised, a production line would be set up and parts would be manufactured and assembled using conventional methods. But 3D printing has now improved to the point that it is starting to be used to produce the finished items themselves (see article). It is already competitive with plastic injection-moulding for runs of around 1,000 items, and this figure will rise as the technology matures. And because each item is created individually, rather than from a single mould, each can be made slightly differently at almost no extra cost. Mass production could, in short, give way to mass customisation for all kinds of products, from shoes to spectacles to kitchenware.

Imagine the following: You design or modify a pair of trainer shoes to to exactly the right size, style and colour you want on a computer, or downloading a design from the web and customising it. Then press print and a device on your desk manufactures them (perhaps one first) for you. Presto, but not quite right. So you make a few minor modifications and print a new pair of perfect shoes.

The 3D printers currently available use a variety of technologies, each of which is suited to different applications. They range in price from under $10,000 to more than $1m for a high-end device capable of making sophisticated production parts. Depending on the size of the object, the material it is made from and the level of detail required, the printing process takes around an hour for a relatively small, simple object that would fit into the palm of your hand, and up to a day for a bigger, more sophisticated part. The latest machines can produce objects to an accuracy of slightly less than 0.1mm.

Jay Leno, an American television celebrity and car collector, bought a Stratasys printing machine to help keep his large collection of old cars on the road. He can scan a broken part that is no longer available into a computer, or design a missing one from scratch, and then print out a copy made of plastic. This can be fitted to a vehicle to check that the design is correct. After any adjustments, a final plastic copy can either be used by a machinist to make an exact copy from metal, or the model’s numerical data can be fed directly into a computer-controlled milling machine. Mr Leno’s 1907 White steam-driven car is now back on the road thanks to his 3-D printer.

For more information, please read The Economists series of articles on 3D printing at How a new manufacturing technology will change the world

Suggested by
Ian Skellern