​Nearly all of us at one time or another heard that 3D printing will change industrial manufacturing in major ways. However, only a look at the past gives any indication of how big the changes will really be: Even the ancient Egyptians used to cut sand stone from mountains by means of simple ropes. Although today’s wire saws use diamond-plated or steel wire and are powered by motors, the principle has remained the same for more than 2,000 years. Be it a hemp rope or a high-tech saw: Both remove material, and so do drilling, milling, planing or grinding. For centuries, these cutting and machining technologies have been removing wood and metal and, more recently, plastics or ceramics as well, and so enable the creation of defined components. 3D printing operates in a totally different way, as Carsten Merklein, the head of Schaeffler’s Additive Manufacturing department, explains: “We no longer remove material to produce something – we simply add it and in this way cause things to directly materialize from powders, pastes or liquids. This simply did not exist before,” says the expert. But that’s not the only reason why Merklein regards 3D printing as the biggest manufacturing technology leap in the past 200 years. “Unlike in machining, where a lot of excess material is lost, only the amount of material required to produce something is applied in 3D printing. This saves resources.” Arguably the biggest advantage in Merklein’s view, though, is this: “No matter whether it’s machining, casting, deep drawing or even CNC-milling – there’s no other manufacturing technology that makes it possible to transfer digital designs so directly into the material world as 3D printing.”

Merklein is by far not the only one to hold this view. Prominent support, among others, includes that of Barack Obama who in a state of the union address in 2013 said, “3D printing has the potential to revolutionize the way we make almost everything.” Former U.S. Vice President Al Gore in his book “The Future” even compares the new manufacturing technology with the introduction of the assembly line in the automotive industry by Henry Ford at the beginning of the past century. And 3D printing pioneer Neil Gershenfeld, a professor at the Massachusetts Institute of Technology, even expresses a more emphatic assessment by predicting that 3D printing will not only redefine power structures in industrial manufacturing but disrupt the business world as a whole. However, the enormous potential of 3D printing will be anything but easy to tap, as Schaeffler’s specialist Merklein explains: “Components can and must be designed in completely different ways for 3D printing – this presupposes a totally new type of thinking.”

3D printing is not always cost-efficient

For this reason, Schaeffler and many other companies have long begun to explore the manufacturing principle that was first described by the Japanese scientist Hideo Kodama as early as in 1981. “We introduced additive technology in the late 1990s, at first exclusively for rapid prototyping and since 2012 for producing functional components as well,” says Merklein. Subsequently, the growing importance of 3D printing motivated Schaeff­ler to make further investments in the technology: In 2015, an “Additive Manufacturing Fab Shop” was established. “That’s a hybrid of a so-called FabLab for experimentation and a shop floor for production,” explains the expert. One of the objectives pursued by his team of currently nine members is to drive additive manufacturing of smart tools and functional prototypes using 3D printing for customer applications, says Merklein. “On the other hand, we’re already systematically investigating opportunities for additive technology to make positive contributions to our production system.”

© Schaeffler

​Components can and must be designed in completely different ways for 3D printing

Carsten Merklein,
Schaeffler Additive Manufacturing

Colleagues from other departments who have heard about this topic regularly visit Merklein’s fab shop kingdom to ask if a specific part can also be 3D-printed. “Typically, these are still components that have been designed for conventional manufacturing,” says Schaeffler’s additive manufacturing expert. In that case, he and his team investigate to what extent a 3D printing-friendly design is possible so that the benefits of the new technology can be used.

“In many cases, this is possible but in others it’s not,” says Merklein. “As a rule of thumb we can say that the greater the complexity of the component and the smaller the production volume, the more an additive method currently pays off. However, the costs have to be carefully analyzed on a case by case basis.” One of the advantages of 3D printing, which per se is a complex technology, is the fact that because tools or casting molds are no longer necessary even the production of small volumes may be a cost-efficient option. Another benefit lies in the fact that 3D printing methods allow shapes to be produced that are impossible or only very difficult to make using conventional technologies. “A case in point are meandering cooling ducts for injection molding where you’d have to drill around a corner which, as we all know, doesn’t work,” explains Schaeffler’s specialist.

© DMG Mori

Printer manufacturers have more homework to do too

Time savings are another advantage: “While today I still have to produce spare parts at our manufacturing site and then ship them to customers all over the world I’ll be able to print them for repair at flexible local manufacturing sites in the future,” says Merklein. That saves time and money. However, not everything will be feasible using 3D printing in the future: “A cast component of which 250,000 units are required will not be produced by additive technology in more economical ways in the future either,” says the expert. And besides that, a lot more development work, also on the part of the 3D printer manufacturers, will still be necessary before usable production parts are available in all areas where they make sense. “For many applications, reproducibility of the printing results, printing speed, automation of the processes and the range of suitable materials are still in need of significant improvement,” says department head Merklein.

According to Schaeffler’s expert, some more time will pass before significant improvements will hit the market. But that wouldn’t mean less work for him and his team. The analysis of existing processes, employment of additive manufacturing in areas where this is already possible today – plus continually building the know­ledge base about 3D printing methods by means of in-house training programs – are already causing his team to work at full capacity today. “We’re going to grow in the short to medium term,” says Merklein. In any event, his vision of establishing additive manufacturing as an equivalent technology in Schaeffler’s production system in ten years will not be achievable without a powerful team. “But that’s where we’ll need to arrive,” says Merklein, “because at the end of the day, it will be tier 1 suppliers like Schaeffler providing automotive OEMs with components produced by additive manufacturing from 3D printers.”