RepRap: The 3D printer that's heading for your home

Once the preserve of large companies, 3D printing is now heading for the home. The founder of the open source 3D printer project RepRap tells TechRepublic about the coming revolution in home manufacturing.

Imagine if replacing a cell phone was as easy as booting up your computer and printing off a new one.

It may seem far fetched today but within a decade Dr Adrian Bowyer, the founder of a movement to spread low cost 3D printers, believes there will be home machines capable of fabricating a working handset.

”If you want my best guess I'd say we'd be printing a phone in seven to 10 years. It won't be a full smartphone, it'll be the equivalent of a £15 Nokia phone, but it'll work.”

Bowyer should know. Since 2005 the lecturer at the University of Bath in England has been running RepRap, a project to designed to bring 3D printing to the masses.

The idea for RepRap struck Bowyer after the university got its first 3D printer.

”I thought ‘This is really neat technology, pity that it costs so much money’,” he said.

”When I looked at how they worked it seemed there was nothing much in there that was worth £30,000. I reckoned that I could probably do it for a few hundred pounds, and as it turns out I was right.”

Bowyer took it upon himself to design a low-cost 3D printer that could print in plastic and was capable of making copies of itself. The first RepRap 3D printer, named Darwin, was complete in 2007, and thanks to its open source design, enthusiasts were quick to build their own versions of the machine.

Today not only are there are an estimated 20,000 people using RepRap machines, the schematics for which are freely available online, but other groups have taken RepRap designs and modded them to create successful low-cost printers of their own, such as the US firm MakerBot and British firm Bits from Bytes.

This growing glut of DIY fabricators is slowly bringing down the price of 3D printing. The cheapest RepRap 3D printer, known as Huxley, can be bought as a kit online for about £430, or less if someone is prepared to source the parts themselves.

A Huxley RepRap 3D printer that has printed out its own parts. Photo: The RepRap Project:

RepRap printers typically build 3D objects by layering molten plastic onto a base, taking about 30 minutes to produce a small item such as a plastic joint. Typically the two plastics used in RepRap machines are ABS and polylactic acid, a biodegradable plastic derived from plants. However RepRap printers are customisable, and modders have made machines that print using a range of materials, such as clay and ceramics.

What's next for 3D printing?

The holy grail for 3D printing, and what Bowyer hopes RepRap will one day produce, is a machine that can print using several different materials at once - such as plastics, metals, rubbers and ceramics - and finely balance the proportions of each. Once achieved 3D printers will start producing objects approaching the structural complexity of something like a cell phone.

”The more different materials you put into a component the closer it becomes to a finished product. If the product is a mobile phone we can't do it today - though in a short while we hope to be able to print the circuitry, but not the chips, for a mobile phone. Once we get something like inkjet electronics printing system working then you'll be able to print the entire phone.”

While nobody is printing phones at home yet a research student working with Bowyer is building a RepRap printer that can create a simple computer motherboard. The prototype machine can produce both 2D and 3D circuits, layering molten plastics and a low melting point metal to create plastics with embedded metal tracks.

”He's on the verge of making his first computer using the technique. We expect in a very few weeks time he will have successfully printed the circuit with the chip holders in,” he said.

In future Bowyer hopes to augment RepRap printers' ability to produce circuitry by adding inkjet print heads that can lay circuits of semi-conducting material onto plastics.

RepRap modders can innovate more rapidly than high end commercial 3D printer manufactures, Bowyer claims, because the open source community of modders is larger than the pool of engineers working for any one company.

”We have thousands of engineers all over the world tinkering with it and chipping in ideas for free which everyone gets access to, so our rate of advance is so much faster. The vast majority of those ideas are rubbish, but that's fine, only three out of 100 need to be really good for the whole project to move forward very fast indeed,” he said.

The RepRap revolution?

RepRap is not just about making 3D printing cheaper, it's about making it ubiquitous. Ultimately Bowyer’s hopes that RepRap-derived printers will be so useful that people will want to make new copies of the machine themselves.

”I have made about 300 machines for other people and my co-workers in my company have made getting on for 1,000. You don't need very many people making hundreds of machines for there to be an awful lot of machines out there.”

Excluding nuts and bolts, existing RepRap printers can print out just over half of the parts needed to build a new RepRap machine, and Bowyer estimates that within five years this ratio will rise to 90 per cent.

Assembling a RepRap machine - bolting together the scaffolds, connecting the print heads and wiring up the electronics and motors - requires somewhere around GCSE to A-level level of expertise in electronics, computing and engineering.

An online community has grown up around RepRap, with a wealth of wikis, forums and chat channels providing advice on how to build, maintain and improve the machines.

Printing out an object using RepRap is straightforward, users download the schematics for the item they are interested in, drop it into one of the open-source software packages – such as Skeinforge - that formats the blueprint for RepRap, send it to the machine and hit print.

Welcome to the Thingiverse

As RepRap users have grown in number, so the range of items that can be printed out using the machines has rocketed. A quick visit to, reveals reams of items - ranging from quadroceptors to artificial shells for hermit crabs - most of which can be downloaded and printed out using a RepRap-derived machine, and all of which are freely available.

A shot of the Thingiverse website showing a rather nifty mini robot rover. Photo: Heath

”There are tens of thousands of objects on Thingiverse, from ridiculous things like a carrot holder to useful things like water filters for use in developing countries,” Bowyer said, adding that the website encourages people to modify designs and upload the results – allowing products to be continually refined.

The personalised nature of items on Thingiverse demonstrates how 3D printing can make bespoke items affordable. Once 3D printers are widespread in businesses and homes people will be able to tweak furniture and ornaments to their liking, as customisation costs no more than the time it takes to tweak a digital schematic.

”Everything is free, you can just download it and print it on your machine – the whole thing is a bit like music file sharing except for solid objects,” he said, raising the prospect of an online market in free, open source physical goods that will – to some extent – replace centrally manufactured paid for items.

”You can see examples where whole industries have largely disappeared with the advent of a particular piece of technology. For example today everybody in the developed world runs their own photographic laboratory and their own printing press.

”The area where 3D printing will impact first of all is in the production of large-scale but simple objects that everybody uses,” he said, giving the example of plastic coat hooks, an industry that he said is worth more than the market for jet engines.

”When everybody can make their own coat hooks there probably isn't a world market for coat hooks any more, so an industry that's bigger than the industry that makes jet engines will disappear.”

As an interim step before 3D printing at home takes off, Bowyer said that local 3D printing bureaus may emerge, where people can collect 3D printed items they have ordered, as happened during the early days of laser printers. Just having these bureaus could make it easier to obtain parts for cars or domestic appliances than the current system that relies on them being manufactured and shipped.

Looking to the far future Bowyer anticipates that groups will collaborate to print 3D large 3D objects – maybe even bringing car manufacture to the home.

"I doubt that anybody will be using this technology to make oil supertankers any time soon, but I can see a time 10 or 15 years from now when a group of people in a village might get together and say 'We will use our 30 3D printers we have between us to print an open source car for someone over a space of a few weeks'."