Jan 1st 2014 was the day the dam burst on additive manufacture.
3D Systems and Stratasys – the dominant players in the space – were unstoppable. Sales were growing 50% a year, and their shares were worth 18x and 7x more than just four years prior. Investors were making fortunes.
But then, over the next two years their stocks crashed back to their 2012 levels, where they have remained since. What the hell happened?
In a word – Hype.
3D printing had been around since the eighties, but as bulky, industrial machines costing $50,000+. Then in 2009 something changed – the first Fused Deposition Modelling (FDM) patents expired. Suddenly, anyone could build and sell plastics 3D printers.
The great thing about FDM is it’s cheap and easy. There are no lasers and high-speed spinning mirrors to worry about. No toxic chemicals. You just need some plastic filament, a heated nozzle and three motorised axes…
An avalanche of startups entered the space, producing systems that were small and cheap enough to be sold to almost anyone. Soon people were asking themselves if 3D Printers were going to be the next microwave or smart phone.
3D Systems and Stratasys were quick to recognise the opportunity, and rapidly developed their own consumer-level printers. It was a good move, and by 2011 their previously flat revenues were growing by 50% a year.
A media frenzy built over 3D Printing’s grand potential to revolutionise everything. Investors started taking note. Most didn’t know a thing about the technology, other than it was looking increasingly like The Next Big Thing and they afford to couldn’t miss out.
Investment started piling into the industry, much of it into the only two publicly traded stocks on the market – 3D Systems and Stratasys.
3D Printing’s meteoric rise had begun.
In 2010 I had just started my Engineering degree and instantly fell in love with the concept – it was going to revolutionise manufacturing, and then the world!
Warwick was a 3D Printing research hub, granting me access to some of the finest industrial printers on the planet, and a look in on a host of experimental systems years before they saw the light of day.
I even had the chance to help develop a couple of experimental 3D printers, including a metals system that printed using a 2kW laser line (that’s two million times more powerful than a laser pointer) instead of a dot in an attempt to sidestep patents and achieve inexpensive metals printing.
But by 2013 doubts were forming. The media had built up impossibly high expectations in my mind, but up close, the tech just kind of sucked…
Our department had it all – Industrial FDM, Stereolithography, Selective Laser Melting, Polyjet, the works.
Each process had at least one deep, fundamental flaw rendering it permanently inappropriate except in very niche applications.
In FDM, the resolution was low, surface finishes terrible, and bonds between layers weak. Improving these meant near-exponential increases to build time and cost.
Stereolithography and Polyjet parts could be incredibly detailed, but were also weak, expensive, and, being made from light reactive resin, the prints became brittle when left exposed to bright light.
Metal prints would warp and bend by up to a cm when cut from the baseplate from the internal residual stresses formed by the intense heat of the process. It was also phenomenally slow and expensive, taking days to make prints that would cost thousands, and often fail mid-build leading to weeks of iteration per part. The material properties would vary from build to build, with micro-pores and fissures drastically reducing the strength of the parts versus forged or CNC machined parts.
The metal prints would then need to be CNC machined to achieve the necessary tolerances and surface finishes, typically accounting for 70% of the cost of the print and adding weeks of lead time.
The parts we produced were usually either too expensive, too weak or too challenging to produce correctly for any mainstream commercial applications.
Time has moved on, and plastics 3D printing is maturing. The tech is significantly more polished and reliable.
In metal printing we’re starting to see smarter software and improved hardware solve the warping/cracking/build fail issues.
But for both plastics and metals printing, the same fundamental limits on strength, speed, accuracy, surface finish and precision still exist.
There is one truly fundamental advantage 3D printing has over other more traditional techniques like CNC machining or Injection Moulding – you can create geometries that are virtually impossible to make any other way.
Why would we want parts like this?
Because the in-service cost savings of such a component can sometimes outweigh their additional development, testing, certification and manufacturing costs. In these rare cases, 3D Printing starts to make sense.
The complex organic forms of generatively designed aircraft components feature material only along load paths, saving weight and reducing fuel expenditure over the lifetime of the aircraft.
Complex internal cooling channels in a 3D printed injection mould can increase the rate of production by reducing the time the mould needs to spend cooling between parts.
People are simply willing to pay more for custom dental implants.
The catch with any of these applications is that 3D Printing isn’t making a final use component – it’s producing to nearly the final shape, but it will usually need to be finished to tolerance using CNC machining. This step alone typically multiplies the cost of the part by 3x.
Speed and ease of prototyping is not a fundamental advantage of the process.
3D Printing is for the most part autononous – you give the machine a 3D file, select some parameters such as layer thickness and resolution, then press go and walk away, at least in theory – this description is more true for plastic than metals printing.
Traditional manufacturing processes such as CNC Machining, sheet metal forming or injection moulding are substantially manual – multiple skilled humans need to work together in an often specialist factory to turn your 3D file into a finished component. But this isn’t a fundamental limit – it’s just so hard to autonomise these processes that it hasn’t been done yet.
But one day soon it will, and production of prototypes using the final intended manufacturing process will become cheaper, faster and better than using 3D Printing.
So this advantage has a time limit defined by the arrival of autonomous manufacturing, and it’s starting to expire.
A machine in your office/facility is over-rated when you can get parts single-click from a factory next or same day.
Proto Labs is a great example if we want a glimpse into the future. You can have a machined or moulded prototype in days. The present-day catch is you need to be willing to tolerate significant design constraints, >0.125mm tolerancing (5-10x too poor for mainstream manufacturing), and a 10x pricing premium.
Strict design constraints, extensive standardisation of process and equipment, and slick operational techniques like programming your machines overnight in the USA using staff in Japan mean they can pull this off, but it’s not autonomous manufacturing.
Badly made prototypes delivered quickly but expensively fulfils a large market need – 2018 revenue was $448M – but the future of CNC Machining is tight tolerances and perfect quality, reliably delivered next day in almost any quantity, at half the cost of today.
We should hold the same high expectations for the future from all manufacturing processes.
When people get excited about 3D Printing, what they’re really getting excited by is the concept of Autonomous Manufacturing – the ability to produce anything instantly and automatically at the press of a button.
This concept is genuinely exciting, but it’s exponentially more challenging to achieve, or explain.
Take a look at any product around you. It’s an assembly of many different components, each created from varying materials by substantially different manufacturing processes.
Consumer devices, buildings, cars, aircraft, furniture… The things that make up the modern world aren’t made by machines, or even factories. They’re made by supply chains. Tens, hundreds, sometimes even thousands of factories working together to gradually turn raw materials into something we would recognise as a product.
This is why 3D printing in the home is useless – almost nothing you would want is made from a single material.
3D Printing gives us the ability to make a vast range of component geometries, but as a jack-of-all-trades it is master of none.
Why print a car door panel when we can use hydraulic stampers to press sheet metal blanks into the right shape before robotic-laser-welding them together? Because for automotive quantities this is <1/1000th the cost.
Why 3D print a spring when we can spend six weeks setting up an 9-Axis CNC Coiling Machine? Because then we can make thousands to millions for pennies or less each.
Why print a turbine blade when we can cast it in nickel super-alloy, cnc machine it to shape, anneal it to achieve a single-crystal-structure, laser drill micro-channels for cooling, broach the connecting faces, and then coat it in ceramic? Sounds complicated, even with dozens of the steps missing, and that’s the point.
3D printing is rarely a substitute for the complex combinations of specialised processes we use to assemble the products of the modern world.
In 2011 the world set this process an impossibly high bar. It was going to deliver on-demand manufacturing in our houses, custom replacement organs, an age of mass customisation and insert-hype-here etc…
It will never live up to the original hype.
Instead we should be viewing it for what it is – a group of highly specialised manufacturing processes with good value propositions against a narrow range of applications, just as with any other manufacturing process type.
The future of 3D printing is boring. It’s simply another tool in the engineer’s toolbox just like the rest, sometimes usefully applicable to make a part faster/better/cheaper.
Against this much more reasonable expectation, I’m excited about the future of the process, and its growing place in the supply chains that make the products of our modern world.
So if the future of manufacturing isn’t 3D Printing, what is it? Read our breakdown on the next industrial revolution and why it hasn’t arrived yet here.