Thousands of miles separate Matt Burris from Chris Elsworthy, yet both engineers share a common goal. Each is working on his own 3D printing system that he believes will one day spread the technology into an untapped market.
The audiences the two men have in mind are poles apart. In San Francisco, Matt Burris, CEO and co-founder of MatterFab, has spent the past two years developing a metal 3D printer. It's designed to enable standard machine shops to produce quality components for about a tenth of the price of current metal 3D printing systems.
Burris knows 3D printers can match traditional methods. He grew up in his father's aerospace parts machine shop, and used to work on the jet engine nozzle that GE Aviation recently switched from conventional production to its own 3D printing facility in Auburn, Alabama.
"GE is now printing their new fuel-injection nozzle and they're using that on the new Leap engine. That part we're actually very familiar with because we used to machine it," Burris said.
"We saw that part transition out of the standard machine shop and start being 3D-printed. We saw this early on. We realised that if they can print a part that demands that kind of quality and reliability, there's not going to be too many limits to what you can print."
GE Aviation's 3D printing machines — of a type that can typically cost between $1m and $2m — are printing a single metal part that used to be manufactured as 18 separate components, which then had to be welded together.
In Portishead near Bristol in the UK, Chris Elsworthy has the consumer in his sights with the Robox plastic 3D printer. The dual-nozzle machine should be available by the end of September in various countries worldwide for $1,399 or £850.
Unlike Matt Burris' manufacturing focus for the MatterFab machine, it's still not entirely clear what consumers will be doing with Elsworthy's printer. Toys, models and one-off household DIY items are possible, with areas such as cookery also emerging as candidates.
"Every consumer we show the technology to, they always seem impressed by it. It's quite magical in the way it makes things but it's always, 'What will we print?'," Elsworthy said.
"That's the biggest question by far. Like any new emerging technology, it's the question that everything faces. So when the internet appeared, no-one thought they were going to use it. They thought, 'What are we going to use it for?' and the same for the telephone."
Elsworthy believes the fall in the cost of the technology will open it up to a far wider audience. That in turn will lead to better, more consumer-friendly CAD software — in similar vein to packages such as Tinkercad and SketchUp. The software will allow consumers to create a range of new models in addition to the objects already available in web-based libraries.
"We're focused on getting the hardware right. Hopefully, immediately people will be able to download content from the internet and print it without any steep learning curve," he said.
"Then we'll move on to focusing on the software, so that people can create content of their own. But it's a chicken-and-egg thing: you can't do one without the other."
If falling costs are what should lead to new consumer applications, they are also what has made Matt Burris' MatterFab 3D printer possible in the first place. Along with cheaper computing power and high-precision sensors, the lasers that weld the alloy powder layers together to form metal parts have dropped in price.
"A lot of laser technology has advanced to the point where we can use a radically different laser system and that really helps drop the price," Burris said.
"The other thing is that when we looked at these systems, we found a lot of places where we could really redesign them and in that redesign we could keep all the same features but build the system a lot cheaper."
For example, existing metal 3D printers commonly have a shielded window to allow operators to monitor the process but protect them from the high-power lasers that would otherwise instantly blind them.
"Even the reflections will blind people, so that window is very expensive. We've replaced that with a couple of cameras and a touch-screen interface, so you can see everything that's going on inside the system. That drops the cost dramatically," Burris said.
The MatterFab 3D printer, which should be delivered to test partners early in 2015, uses a full melting process that the company describes as 'selective metal welding'. It will be able to produce parts that are every bit as strong as traditionally produced components, Burris said.
"For those really high-end [3D printing] applications, they will typically do a little post-processing, either to polish it up or to increase the strength a little bit," he said.
"There are standard industrial processes that they often do to parts that they mill. In the case of the GE fuel-injection nozzle it's called HIP — it's high-temperature isostatic pressing."
Both Burris and Elsworthy believe that increasing the range of materials that can be used in 3D printing is key to increasing uptake of the technology and unlocking new applications.
"This is the largest growth path for the hardware itself, because once you can print in multiple materials and in a much wider variety of materials, then the technology gets even more usable," Elsworthy said.
"Our Robox can take a huge range of plastics straightaway. Then we intend to go to make a paste-extrusion head. Rather than extruding what is a solid plastic, you'll be able to put a semi-liquid into it like icing sugar or solder paste or clay.
"So you get away from that plastic part that 3D printing has been connected with up to now, and into making pottery or cake decorations or making edible things on the 3D printer."
Matt Burris said the selection of materials for metal 3D printing is also limited and represents a very large barrier to entry.
"If you look at the major manufacturers of these systems, you're looking at about 15, maybe 20, alloys that are available through them. That really limits where it can be used without forcing a company to redesign their parts to make sure they work in the available alloys," he said.
"As you see the material availability start to climb and the common alloys that these industries use becoming available, you're going to see much more adoption and use of these kinds of systems. If you're forcing me to redesign my part because I have to use a different alloy, that's a non-starter for a lot of people."
The biggest single challenge is tying the material — a prealloyed powder — to the laser parameters. It takes time to dial in those parameters to get a good-quality output.
"There are a lot of subtleties to it. You have to have good flow of your powder so you can spread it easily. Every time you change the thickness of that layer, you're going to have to change your printing parameters. Because you're melting through a deeper layer of powder, some of the behaviour around that does change," Burris said.
"The simple way to look at it is you have to put in enough energy to melt that powder — and of course melt some of the layer below because you're trying to weld to it. So you need to make sure you have a very good weld and bond between those layers."
Although both engineers are aiming to produce lower-cost 3D printers for their respective markets, the price of the technology still has further to fall.
Elsworthy said in the consumer sphere the technology is now halfway down that price slope.
"A lot of the people who are making printers are having to build in quite large margins because of the amount of service they have to give the consumer after they've purchased the product," he said.
"If they use the printer in exactly the way it's intended, it should work properly, but no-one does that. Everyone just opens the box and gets straight on with using it in the way they think it should be used. If something goes wrong, you have to get it fixed and that comes out of the overhead of the costs originally.
"Once the technology starts to settle down, you'll see that price start to plummet. You've seen the same thing with colour 2D laser printers. It's still the same laser printer it was five years ago. But it's just that they've ironed out all the wrinkles."
Speed versus quality
With that evolution of the reliability of the technology and falling prices, Elsworthy expects print speeds to increase.
"For us it depends on the quality of the part you want. We've got this two-nozzle system, which means that you can deposit quite a lot of material quite quickly. But at the other end of that if you want to do things quickly, you lose quality," he said.
"Speed is obviously always compared against something, and because there's nothing that has really taken a foothold yet, anything is amazing at the moment."
In metal 3D printing, speed can come into play with the size of the object being produced, according to Matt Burris.
"Right now the technology is not there yet to build very large objects. There are two big challenges around that. One is that it takes a long time to print so it might not be an economical option for a lot of very large objects," he said.
"But the other issue is there's some stress build-up as you use this process and that can warp large parts. So it becomes more of a challenge to print large things and get the part out correctly."
Another area that could represent a barrier to metal 3D printing is surface finish, which is currently rough "like very fine-grit sandpaper", Burris said.
"In some applications that's great; in a lot that's not what people are expecting. They want it a lot more polished. There are techniques that people are exploring to be able to polish things up in the process but none of that has been commercialised," he said
That rough finish can prove a benefit. For example, the roughness inside the cooling channels in the 3D-printed fuel nozzle of SpaceX's SuperDraco rocket provides more surface area, which is conducive to removing heat.
A disruptive technology
In the wider scheme of things, Burris believes the spread of 3D metal printing will have major repercussions — some of them beyond the world of manufacturing.
"Long term, the technology will be able to displace a significant proportion of CNC machining. It's really going to improve the standard of living across the globe. It's also really going to reshape the landscape of manufacturing," he said.
"When you look at 3D printing, what you can start to do is really tie together the way you think about design and the way you manufacture. Right now they are fairly decoupled, but we can take the data we can get off these machines and feed that back into the design very easily, and that enables data-driven designs.
"It allows you to do a lot more things that you could never do before. A lot of parts have a very standard component, but also some part of it might be customised. So you can actually start making that part, making the standard portion of it first. Once you reach that point where you need to customise it, you can add that in during the manufacturing process."
Metal 3D printing will also allow manufacturers to ensure a part is being built correctly during the process and change the design if anomalies start to appear, before full-scale production begins and well before the part goes into service.
Chris Elsworthy also foresees widespread change in the long term, primarily in the transportation of products.
"Obviously, most of the goods that we transport are finished goods, but you can see that quite quickly changing from finished product to raw material," he said.
Retailers could start taking shipments of raw materials rather than finished products, manufacturing custom-built orders rather than selling all the products off the shelf.
"Obviously, we all rely on the Far East producing all our products at the moment. But you can see that more resource-rich places like Africa might be shipping the raw materials out from there," Elsworthy said.
"It's interesting that you see that China is probably one of the most heavily into 3D printing right now. They have three or four universities dedicated to 3D printing. They've obviously got their eye on the ball and know exactly what's on the horizon."