Late last December, Siemens announced the opening of a metal 3D printing manufacturing center and invited engineering.com to attend. We got to Worcester by driving from Birmingham. Sheep grazed between the hedgerows. We wonder, why build a manufacturing center here? Then we remember. The area claims to have birthed the industrial revolution. The Midlands, to this day, are the industrial heart of the UK. Siemens has several facilities nearby that service and provide for the planes, trains and power stations, part of its network of 45 offices in the UK.
Also close by is Rolls Royce, make of iconic cars, but more important for this story, its jet engines and the parts required in their assembly.
Worcester (pronounced “wooster” for no reason other than for locals to tell you that you don’t belong) is most familiar for its Worcestershire sauce, created by chemists John Wheely Lea and William Henry Perrins, who began fermenting their mixture in 1835. Locals today are more interested in fermentation of a different sort. Our driver regales us with all the pubs we have to try. In passing is mentioned the cathedral, the final resting place of King John, who loosened royalty’s hold on the country by signing the Magna Carta.
And then we see the 4,500 square meters of some of the most modern 3D printing facilities in the industry. Siemens very much wants to play a role in the next industrial revolution. This facility is “the next step toward achieving our ambition of pioneering the industrialization of 3D printing and demonstrates how we are leading the way for the fourth industrial revolution,” says Siemens UK CEO Juergen Maier in the company’s press release.
Let’s call it additive manufacturing (AM), corrects Markus Siebold, VP at Siemens Power and Gas division, who has come from Siemens HQ in Erlangen, Germany to open the Material Solutions facility and show it off to an international assemblage of media. Material Solutions, Ltd, established in 2006, is 85% owned by Siemens. While desktop 3D printers sit on tables and come with an implication of toys and games, figurines and plastic, this facility is for serious business. We’re talking about production of metal parts, steels and titanium, made in quantity. No plastics.
All of the machines in the Siemens facility make metal parts. These hulking machines, some as big as small rooms and created by EOS and Renishaw, cost anywhere from $300,000 to over $1,000,000, according to Phil Hatherley, general manager of the Worcester facility. Siemens plans on having up to 50 metal printers, investing a total of €30 million in the new facility.
A History in Parts
The story of Siemens in AM is best told in parts. Siebold credits Vladimir Navrotsky, a Russian who, in 2009, had a vision for a turbine blade for Siemens’ industrial turbomachinery division. Vladimir had written his doctorate thesis and sketched out an internal structure that would be able to transfer heat from the blade. The channels can convey fluid, but there was no way to create them, no way to machine inside the blade.
But a 3D printer, creating one layer at a time, can make just about any part you can imagine. The first machine purchased was an EOSINT M270, which led to more in Material Solutions first metal printing facility in Finspång, Sweden. When a customer found that it was possible replace the tip of a turbine combustion nozzle by machining it away and rebuilding the design shape with AM, at a savings of thousands of dollars each, another successful application was found.
The Ruston Hornsby is Revived
Another project shown is not a commercial success but a labor of love by three of the centers’ employees, Dick Amos, Jeremy (Jez) Hunt and Steve Wildman. They have their heart set on bringing a Ruston Hornsby back to life. They work on it in their own time.
The last of the open-cabin, black sedan came out of a factory in the nearby town of Lincoln a hundred years ago and sold for the princely sum of £475. It had solid rubber tires and straw mat on running boards, so its top-hatted and bonneted passengers could wipe horse poop off their shoes. Of course, parts needed for its restoration are hard to come by, for example, the steering wheel box.
3D Scanning, Twins
The old steering box was 3D scanned in a room on the factory floor. An enclosure protects humans from a robotic arm, on which a 3D laser scanner is mounted, as it makes automated passes around an object. Also present is a big granite slab on which a contact scanner is poised. A workstation is running NX, ready to design parts or modify them.
A MindSphere—the open-source, cloud-based Internet-of-Things operating system Siemens bought—is set up to remind us of Siemens intent to create and support digital twins.
Serial Production
Siemens has become the number one 3D-printed metal parts manufacturer, according to Siebold. It is the Siemens way. We are not interested in anything unless we can be leaders, he says.
Siemens—one of the world’s biggest manufacturers, employing more people than live in the entire city of Worcester (350,000, according to the website)—would seem to be able to will itself into a leadership position in anything it sets its corporate mind to.
“There is no country we are not in,” continues Siebold. “No other company puts this much stake in additive –or has as much experience and knowledge.”
First steps towards world domination in industrial metal part production are big auto and big aviation.
Every automaker is looking at additive, says Siebold. We are not at a point we can make—or want to make—every door handle in a car. That takes production runs of hundreds of thousands, for which casting and molds still make the most sense.
Siemens is comfortably able to make parts in quantities of thousands, which they refer to as serial production, as opposed to mass production, quite unaware that most non-Germans will associate serial production with corn flakes. Sensible candidates for 3D printing are high-value parts. We are reminded of entire engine blocks one metal 3D printing company (ExOne) wanted to make for BMW about two years ago.
The Operating Room
The “factory,” as we are shown, is spotless. The metal powder we expect to find is not visible.
“It looks like an operating room,” says a member of the media, impressed with its cleanliness.
Metal powder used in AM is fine to the point of being dangerous. It gets airborne and can be inhaled. Our people wear masks and protective clothing when they clean the machines, says general manager Phil Hatherly. Extra care is taken with aluminum and titanium powder, which are fine enough to be explosion risks. Employees on the production floor wear lab coats, aprons and jackets, which they shed when entering office or common areas, and are told to wash their hands.
The company is working toward confining metal powder to big closed hoppers, which are automatically supplied to machines, to reduce handling and exposure. Material Solutions also cites its 12-year experience in using metal additive powders, claiming multiple tests and analysis tracking of powder movement, measurement of airborne particulate, urine samples from workers, etc. to have developed materials handling processes that minimise employee exposure and risk, according to a company spokesperson.
Many of the parts on display have signs reading “Do not photograph.” It’s to protect the customers IP, says Siemens. But we are allowed to touch and feel.
Our hands feel gritty afterwards. I am reminded to wash before lunch.
Outsourcing Production
Siemens plans on doing production AM for industrial customers, many of whom are secretive about their parts and the processes used to make them. A service bureau—as Siemens wants to be seen as for big industry, no doubt—Siemens has to assure customers that their parts don’t turn up with competitors or on in the media, where they can be seen by anyone.
So, why don’t companies make all of their own parts, inside their walls, one might wonder.
Automakers, for example, don’t produce their own parts as a rule, says Siebold. They outsource the manufacturing because it’s cheaper when companies compete for their business. But just to make sure they get the parts right, they saddle the manufacturers with painstaking constructed, immensely detailed spefications. The qualification and certification of AMparts is especially onerous because it is a relatively new process. Service bureaus, if they want the business and even if they are Siemens, have to play by the rules.
But Siemens does not lack confidence, citing its ability to produce turbine parts. “If you can make gas turbine parts, you can make anything,” Siebold says. Indeed, the high heat environment and the RPMs of turbine blade spin has got to be one of the most demanding of all environments. Siemens is proud that its blades have withstood over a total of 110,000 hours of operation in fully functioning power plants.
Metal AMparts have a host of potential problems that need to be addressed. For one thing, the leakage of powder into the voids of a part. Metal AMparts made using powder bed fusion start as a fine powder, as opposed to plastic extrusion, for which the stock material s a filament. Powder, unlike filament, can fill unevenly. Voids can be created inside parts without anyone’s knowledge or their ability to detect it.
Also, the high heat of the laser used to melt and fuse the powder can result in uneven cooling, leading to residual stresses that can warp the part or even crack it. Not a problem, says Siemens’ Vladimir Navrotsky. We have software that can accurately predict how the part will deform, based on machine characteristics, and come up with a starting geometry that will deform into the desired shape.
Is Siemens Its Own Best Customer?
Siemens is a big customer of Material Solutions, especially for its Power Generation division. Although Siemens wants to be seen as an independent supplier of metal parts for all industry players, especially automotive and aerospace, they will choose not to make parts for Siemens’ competitors in the power generation space.
The factory, when fully operational, plans on plugging into Siemens’ Additive Manufacturing Network to which engineers will be able to upload a CAD part and pick from a bazaar of additive manufacturers. In doing so, the factory will have to compete with other 3D printing services that are part of the network. However, most of the orders for the Worcester and Swedish facilities come from Siemens’ own divisions and their established enterprise customers.
Several of the new machines on the floor are on an internal network that could theoretically be accessed externally allowing for automatic, or semi-automatic, production. AM, more than any other type of manufacturing, has the potential to maintain an unbroken digital thread, entering the world digitally as a design and emerging from a 3D printer, without any interruption or attendance by a human, something NC machines cannot deliver. However, Hatherley expressed that for now, he’d much rather see the parts and advise on their construction.