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TCT Magazine + Personalize / EOS GmbH
Dr. Hans J. Langer founded EOS and remains active as its CEO — his vision has driven the company (and the many others in his portfolio) to the top of the industry.
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TCT Magazine + Personalize / EOS GmbH
Bigger than the M400 even is the company's new facilities next to the existing Krailing site — and they're keeping the old site too!
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TCT Magazine + Personalize / EOS GmbH
The new EOS M400 machine is big, but production ready.
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TCT Magazine + Personalize / EOS GmbH
A part made on the M400 — large, dense and (believe me) exceptionally heavy.
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TCT Magazine + Personalize / EOS GmbH
Laser sintered sole for a shoe has firmer and softer areas for support and comfort.
EOS GmbH, based deep in the forests of southern Germany, is one of the most recognisable names in the AM and 3D printing world. Part of this recognition stems from the breadth of applications that the company’s laser sintering technologies are used for — from toys and games through medical, tooling, automotive and aerospace components. In a bid to get the low-down on some exciting developments we had been tipped off about, and to get the whole of the EOS story directly from founder and CEO Dr. Hans J. Langer, TCT took a trip to Munich…
Mittel of the road?
The Germans have a word — Mittelstand — that epitomises many of the companies you’re likely to read about in TCT. The exact translation into English is quite vague and refers to the ‘middle estate’, a throwback from the days of feudal systems and wealthy landowners. What the term really means though is a way of thinking and a way of working that has become lauded as the source of Germany’s persistent economic superiority within Europe, even through the lean years of the financial crisis, credit crunch, recession and currency woes that have beset their continental brethren.
Mittelstand companies are generally small (under 500 employees), focussed on high-tech and high-value manufacturing and engineering applications and are dotted across the German landscape, often in rural locations. Mittelstand companies account for around 70% of the country’s employment and have been hailed a source of innovation and economic resilience. They usually cluster around large enterprises but — importantly — are never reliant on supplying a single customer, instead spreading risk throughout their supply chains and customer bases.
The companies tend to be conservative in their practices, shying away from undue risk and concentrating on stability rather than growth, with emphasis on passing the business on to the next generation in good order (historically Mittelstand companies are family owned) — something that a lot of the Western economy could benefit from studying.
With all that said, business always involves an element of risk and the greatest businessmen are the ones that have taken risks that others would scoff at, something that EOS’s founder and CEO Dr Hans J. Langer appreciates:
“Back in 1988 I was working for a company called General Scanning, a company that at the time had a quasi-monopoly on scanning systems for lasers — the mirrors and actuators that control the position of the laser beam. I had started General Scanning’s European operations and was on the strategy board that was responsible for the direction of the company on the whole. The idea at the time was for the company to move from the components business into very specific areas of system businesses. We knew the laser applications market very well as nearly everyone using lasers at the time used General Scanning systems or components.
“Because of the ubiquity of the company’s products we could see new applications arising very early on in different universities and start-up companies around the world. One of the developments we saw was the use of lasers not for scanning or cutting or milling, but for layer-by-layer manufacturing; in Europe, the USA and Japan there were projects that all used parts from General Scanning. At this time I proposed to the General Scanning board that the company invest into the layer manufacturing world under the name EOS (Electro Optical Systems) as it seemed to be a logical progression in moving the company from components to systems.”
When a door closes, a window opens
What happened next was perhaps the defining moment in Dr Langer’s professional life and for EOS as a company, as the CEO went on to explain: “The board at General Scanning declined the proposal because they were worried about potential patent issues. Of course I was disappointed but by accident I went on to meet an ex-customer of mine here in Germany who had just sold the first laser company and was looking for activities as a business angel.”
With some reassurance from his ‘angel’ as well as the much-needed investment Dr Langer left General Scanning to pursue the EOS concept on his own.
“I started to look at what exactly the other groups interested in additive technologies were doing. Over in the USA Charles Hull was using laser systems to cure photopolymers layer by layer — being a physicist I wondered whether it would also be possible to use lasers to build parts on metals and ceramics also, especially as I had experience of laser welding systems — all that was missing was the Z axis.”
Like all companies, but especially in the early start-up phase, cash flow is the key to success, something that Dr Langer immediately realised. In order to make the fledgling EOS a serious contender in the emerging market the company needed a customer, and for a customer it needed a first product. Attention turned to companies in the local Munich area to approach. After some enquiries Dr Langer found a sizeable interest from a local carmaker — BMW.
“BMW were already interested in early rapid prototyping technologies and so seemed like the obvious choice for EOS. We approached BMW and talked to them about the ideas for both reading and writing with lasers. The company already had a 50-strong team looking at rapid prototyping across all business units. BMW had a specification in mind that they were unable to get built by existing rapid prototyping machine manufacturers so we proposed something to them: for the same cost of an existing machine that did not meet their specification, we would develop and build a machine to match their exact specification. We needed 50% of the total cost up front and 50% upon delivery — if the project failed for any reason BMW would stand to lose that 50%, so this was something of a risk for them. It is also unusual to buy a machine that doesn’t even exist as a drawing, only as a list of specifications.”
Thankfully for EOS BMW finally agreed to the unorthodox arrangement and the team began working on the system. Dr Langer contacted some engineers with whom he had previously worked who were keen to get involved with such a daring project and work commenced on the first machine. Within one year the machine was being delivered to BMW, as per the specification.
Materially impossible
More luck was to follow for EOS as Dr Langer explained: “I knew that the specification that BMW had set would be achievable from a laser hardware point of view, but the project would be set to fail because of difficulties with materials supply.”
At the time Ciba Geigy were supplying 3D Systems with materials for their stereolithography systems, but would not supply BMW with material. The challenge was therefore to find a supplier of a material that would still allow the machine to meet BMW’s specification who was willing to work with an unknown company and an unknown machine. After some research BMW pointed EOS towards Du Pont. As it turned out Du Pont had a material that was not only suitable but would in fact allow EOS to surpass the specifications of the Ciba Geigy material — and Du Pont had also developed a machine to run the material on, which had been shelved because of potential patent issues.
With the materials partnership in place EOS were set for astonishing growth over the next three years, building from 0 to 10 million DM and selling some 20 systems to BMW and its supply chain. The next logical step for the fledgling machine maker — which until this point had taken its fair share of risks — was to diversify its customer base. Its experience within the automotive sector made another carmaker the obvious choice, and Mercedes was identified as a potential customer. Not to be outdone by BMW, Mercedes specified a larger stereolithography machine from EOS, the STEREOS 600 — the STEREOS 400 had been installed at archrival BMW.
The manufacture and sales of stereolithography machines didn’t go unnoticed by 3D Systems in the USA, and the following years saw many patent battles between the two companies. It is telling that now, some 20 years on, Dr Langer dismisses these potentially threatening legal battles with a shrug — water under the bridge as they say.
By 1994 EOS had expanded into one of the areas it is most closely associated with today — laser sintering. The P 350 machine was developed for BMW as the company had realised the potential of the photopolymer systems and wanted to move into small series production parts, initially for concept cars. When its first laser sintering machine was launched EOS became the only company selling both laser sintering and stereolithography systems worldwide.
Behind the scenes the company was working closely with Swedish household and professional appliances manufacturer Electrolux, who had bought the very first stereolithography machine in Europe, a new metal technology dubbed Direct Metal Laser Sintering (DMLS). Electrolux had developed sintering materials for mould making but were using a furnace to process the metals and were struggling to get homogenous structures.
Ever the astute businessman, Dr Langer had one question: “The first thing I asked them was ‘do you have a budget?’. Luckily they did and we then worked to produce for them a machine that enabled direct metal laser sintering — which is now our largest market.”
Enter the sandman
At around the same time a foundry expert, Dr Florian Wendt, was looking to make use of a sand sintering process that he had patented. The patent was of interest to EOS but without any foundry experience there would be no easy way forward. Using connections at BMW’s foundry department Dr Langer started to research whether the sand sintering process could be a viable business move for his rapidly growing company. BMW’s response: ‘If this is real, it could revolutionise the way we work.’
BMW were at the time using sand moulds for cylinder heads, requiring up to 30 pieces of sand to be set into a box before metal is poured into the mould, a time consuming and labour intensive process. EOS took one CAD file from the foundry at BMW (a very early file — at the time the process was still worked by hand!) and built the mould in sand on a modified plastic laser sintering machine. The process was complete in a few hours, so the next logical step was to melt some aluminium and create a part.
Dr Langer recalled with obvious pride: “We decided to use some aluminium to cast a part from the sand pattern we had created as we didn’t have any foundry facilities and aluminium has a low enough melting point to be viable. In under 24 hours we had taken a crude CAD model and produced from it a metal part! I rang BMW and told them that their part was ready. ‘What do you mean part? We gave you a drawing for a mould…’ was the response. When I explained what we had done the engineer who was coming to collect the piece asked, ‘can I bring my boss with me?!’.”
Once the part had been seen a conversation ensued that would drive the next developments of EOS’s platforms:
BMW: ‘Hans, what can we do to protect this technology for some time for us?’
Dr Langer: What do you want to do with it?
BMW: ‘We want to make cylinder heads.’
Cylinder heads are 600 mm and larger, but the plastic laser sintering machines only had 350 mm square build platforms. Making a 600 mm system would in effect require joining two 350 mm systems which, Dr Langer explained, could take years to perfect: “Making a 600 mm sand sintering system would not be easy but we proposed to BMW that we could produce two machines, in two years, for 2 million DM. After some weeks BMW agreed so we had the budget and hired an engineer, Thomas Mattes, and set about making the machines. These machines would process 100 tonnes of sand per year so needed a new way of loading and unloading, which was another innovation we developed.”
The holder of the original patent, Dr Wendt, went on to secure backing from Dr Langer and his business angel to start a foundry for prototype castings. That company, ACTech, are now world leaders in prototype castings. Dr Langer founded another company at around the same time he founded EOS to combat problems that EOS were having in sourcing the laser scanning heads for their growing portfolio of machines. That company, SCANLAB, went on to become the world leader in scanning systems for laser control.
One final innovation was needed to bring EOS to its full range of systems, a dual-laser polymer processing machine, the P 700. Daimler had seen the P 350 at BMW and the dual-laser sand casting machine S 700 and wanted a machine that could process polymers, with the 700 mm build bed, and dual lasers. The P 700 was released in 2,000, just 12 years after Dr Langer had left the 2D world of General Scanning and set up EOS.
Testament to the protracted and disruptive nature of litigation, it was not until 2004 that EOS was able to sell its first metal laser sintering machines in the United States market. One of the first customers, Morris Technologies, wanted to make tooling for local healthcare giant Proctor and Gamble. As Dr Langer pointed out: “In Cincinnati you have not only Proctor and Gamble but also General Electric (GE) who picked up on the technology and started to investigate further. In 2007 Morris and GE visited EOS in Krailling and announced that they were working on a special project together that would come to fruition publicly as the acquisition of Morris by GE Aviation in 2012.”
A turning point to production
GE’s involvement in metals additive manufacturing (AM) was a paradigm shift for all involved as for the first time a business model was created that was larger than the companies providing the machinery. This change in the landscape into a true manufacturing technology spurred on a substantial change in the way EOS has organised itself to move forward and points to the direction of the company in future.
“We realised that companies like GE were really serious about series manufacturing using additive manufacturing. If they are being serious, then we also need to be serious, hence the changes to the management structure to ensure that EOS continues to be at the forefront of innovation in the manufacturing applications of AM,” explained Dr Langer.
Moving from prototyping to series production
Throughout the company’s history the evolution has been easy to chart — from bespoke stereolithography systems through to laser sintering systems and eventually sand and metal laser sintering. Until recently however all of these systems were taken away and used most often in prototyping, but they were being used in some of the most innovative companies in the world, and these companies saw the potential for additive manufacturing as a serious production tool. And once they had seen it, they wanted it.
Where open collaboration with other companies had served EOS well in the early years, it was now time to bring the expertise in-house and make changes to the fundamental structure of the business, as Dr Adrian Keppler, CMO, went on to explain: “I started with EOS four years ago as Hans realised that the company needed to move in a different direction. Transforming from a maker of prototyping machines to a solution provider for series production is a big move and we need a different mind-set, different tools and different technology.
“Our technology was developed for mostly rapid prototyping but our customers could see already the value of additive techniques for series parts. Hans asked me to join to help change the direction of the company to the part production focus. I was working for 10 years at Siemens in a number of roles — one of the things I brought with me from there was that a company must sell a solution to a problem. We don’t sell a product we sell a solution that includes machine, material services as well as upfront software to design the part, simulate the process, monitor the process and then on to hipping, heat treating, finishing and surface optimisation. Based on our long-term expertise we can help our clients build up this process chain so that they get the best out of the technology.”
There have been a host of other changes to the management structure, a QA manager plucked from the medical industry, a software lead from the automotive industry, a head of engineering from the laser machining industry.
Dr Tobias Abeln came to EOS just over two years ago with experience that is invaluable for a company looking to break into true production, as he explained: “Before I came to EOS I worked in the machine tool industry and before that in a company that made special machines for the automotive industry. Both industries share an approach to modularity, reliability and standardisation that is needed when you are making machines that run 3 shifts per day for 365 days per year. If machines are used in a rapid prototyping environment it is maybe not so much of a problem that the machine doesn’t run on Friday afternoons because of maintenance, or that the process of getting the machine running a job is very labour intensive. For a production machine however this is unthinkable, especially when you are competing with other machine tools on the production floor.”
The route to production acceptance is no longer about making the most of the freedom of AM, it is about taking the benchmarks set by other manufacturing technologies, meeting them and then adding the unique benefits of layer-by-layer production to them, as Dr Keppler explained: “In the past a user of an additive manufacturing system would look at the parts from their machine and say ‘this part looks nice, I can use it.’ Now they want the right material, mechanical properties and even microstructure that is available from their existing techniques with the freedom of the AM process as well. We now have to combine something known, such casting, forging, milling with the characteristics only available to AM.”
The development of new solutions is driven by three points of interest: the further optimisation of the process, the increase of productivity and the reduction of cost per part combined with offering new features as well as materials. At the moment, the team believes that the main focus should be on the process in combination with the process-relevant hardware and software. Optimising the process for production includes the reliability and speed to reduce the final cost per part. After the process, materials will become the area that offers the greatest benefits as Dr Keppler explained: “Once the process is properly optimised people will start to create new alloys that can exploit the unique features of AM, but this will take until certain industries to accept AM as a true manufacturing technology.”
Meeting production readiness
At the upcoming EuroMold in Frankfurt EOS will unveil the first machine that truly reflects the new thinking at the company, the EOS M 400 system. A 400 mm x 400 mm x 400 mm modular metals laser sintering machine, the EOS M 400 is the first step on the road to production machines capable of high-throughput series production and the large-scale production platforms that EOS predict will be the future of AM for series production. Featuring semi-automated process to aid throughput and reduce cycle times, the modular principle will launch first with a single field 1 kW laser before being adapted for a multi-field set up with 200/400 W lasers in a second step, the EOS M 400-4.
Single field and multi-field set ups will be employed to meet application-specific needs whereby large parts that will typically undergo some functional surface finishing can be produced quickly and smaller parts that require high-resolution can be produced more accurately.
The production system is composed of three ‘stations’ in a modular fashion: periphery station , process station and set-up station. The periphery station contains the electrical components but also a recirculating filter system with automated filter cleaning removing the need to change filters between production cycles. The process station is what most people would recognise as the traditional ‘machine’ and the set-up station allows tailoring of the solution to specific applications.
Another innovation targeted at the production environment is enhanced monitoring of the machines status including process variables, chamber conditions etc., and also a camera-based powder-bed monitoring system. By taking two pictures of the build bed for each layer (after exposure to the laser and after recoating with fresh material) anomalies in the build can be identified via an EOSTATE plugin. At the moment a feedback system to interfere with the build to recognise and correct errors automatically during the cycle is in development. The ability to review a build and identify errors in the process, however, will be invaluable for QA/QC purposes and process refinement.
€2–3 million can be spent by a medical company in validating and qualifying a manufacturing process and material for an implantable part and can take up to 7 years to complete. For this reason EOS is careful to ensure that new systems can be directly compared back to existing systems (for example the multi-field system EOS M 400-4 back to the EOSINT M 280 so that companies can move from one system to another without the huge cost and time implications.
EOS has been working with Materialise to create so-called ‘build processors’ to set up the job file, something that would be especially important in a production environment. The build processor set up reduces the amount of machine-side time for engineers and is a move towards a centralised control system for multiple AM machines. You can read more about build processors and their applications on page XX of this issue.
Final thought
In summing up the progress from leading a daring start-up to serial entrepreneurship across over a dozen companies, Dr Langer explained: “To be honest I do no look at things in terms of additive manufacturing or laser welding or casting, I am not interested. I look at a part and think ‘how can I make the value of this part higher either in its production or its use?’. There are many ways to make a part more sustainable or improve its function and I try to pass on this philosophy within my companies and to the people I talk to.”
