Frank Herzog was still in elementary school in the historic Bavarian city of Bamberg when he fell in love - with metals. So ardent was his passion that he later quit high school to pursue it. 'I was young when I realized that I loved the material,' he says.
More than three decades later, Herzog's fascination with shiny objects continues. He is the founder and CEO of Concept Laser, a pioneering maker of 3D printing machines, including the world's largest industrial printer for metals. His machines can print delicate jewelry and dental implants as well as massive engine blocks for trucks (see video). In 2016, GE acquired a majority stake in Herzog's company, and Concept Laser is now part of GE Additive, a new GE business dedicated to supplying 3D printers, materials and engineering consulting services.
Above: The Slovak company Kinazo Design 3D-printed this e-bike on a Concept Laser machine. Image credit: Kinazo Design. Top: Frank Herzog fell in love with metals in elementary school. Image credit: concept Laser.
Herzog, 46, grew up in a state that's obsessed with engineering. Mechanical engineers alone account for 17 percent of Bavaria's workforce. But Herzog's family sold clothes. His grandparents owned a fashion shop in Munich. They passed it to his mother, and his father had a small construction equipment business. His father even designed and built the family home. 'I think I got my business acumen from my mother's side and my technical side from my father,' Herzog says.
Young Frank kept his hands greasy. He was 14 when he rigged the engine of a small motorbike and boosted its top speed from 25 kilometers per hour to 100. 'It was illegal, but it was really hot,' he says. 'I turned it into a race bike.'
Herzog's need to tinker made him drop out of high school. He spent the next three years as an apprentice in a factory, soaking up all he could about manufacturing. 'I learned to drill, work with a lathe and a milling machine,' he says. But the program only increased his appetite and curiosity. He went back to school to get his high school diploma and enrolled to study mechanical engineering at Coburg University, a small technical school near Bamberg.
At Coburg, Herzog's relationship with metals soon evolved into a love triangle when he spotted fellow engineering student Kerstin Hofmann in the lecture hall. They started dating, and Kerstin, whose extended family owned several factories and plants around Bamberg, suggested that Herzog earn his extra money by working for her father rather than continuing to work on the weekends as a bricklayer. 'But I felt I would be too exposed as a possible future son-in-law,' he laughs.
As a compromise, he joined a prototyping shop in a nearby town owned by Robert Hofmann, Kerstin's uncle. It was a decision that changed his life. It was the mid-1990s, and the machines in the shop included one of Germany's first stereolithography machines, which 'printed' 3D models from successive layers of resin and solidified them with ultraviolet light. 'I told him, 'Oh, wow, if we could do the same thing with metals, that would be really cool,' ' Herzog says. Robert liked the idea and told him to figure it out. 'So, I took out the proverbial pencil and a piece of paper and I gave it shot,' Herzog says.
Top and Above: Frank Herzog's first, hand-powered 3D printer prototype. 'I took out the proverbial pencil and a piece of paper and I gave it shot,' Herzog says. Image credit: Concept Laser
Many 3D printers and other additive manufacturing machines grow complex parts directly from a computer file by fusing together layers of raw material. Herzog believed that if he replaced the UV light in the stereolithography machine with a laser beam, he would be able to print parts from metals.
He registered the idea as his master's thesis at Coburg and built a small prototype. It used a laser he'd found at school and printed samples from a stainless steel powder used for surface coatings. But the results weren't encouraging. The parts 'looked very nice' from the outside, but inside they were porous and tended to shrink after they cooled.
One evening, after many attempts to print a dense part, he commiserated with Kerstin. 'I've come so far, but now I've reached the end,' he lamented. But Kerstin had a solution. She had purchased a state-of-the-art solid-state laser for her master's project. The laser emitted a continuous, low-frequency light beam, potentially perfect for printing stainless steel parts with uniform structure.
Top image: Frank Herzog and his wife, Kerstin. Her laser helped his with his breakthrough. Image credit: Frank Herzog.
Herzog borrowed the laser, installed it above his 3D printing machine and hooked it up to commercial software to control its movements. He even slept beside the machine at night to make sure he would meet his thesis deadline. 'It took many hours to print the part, and I had to be ready when the machine got stuck at 2:30 in the morning, which really happened,' he says. After many nights, he ended up with a perfectly dense square of steel 1 centimeter long and wide and 10 layers thick. 'When we cut it open, I knew that we won,' he says.
The love's labor paid off. Herzog not only earned his degree but also a 2 million euros investment from Kerstin's father and uncle to commercialize the design. The hitch: They had to do it in two years because the brothers needed the money for other investments.
Herzog and Kerstin incorporated Concept Laser in 2000, took up a small space in Robert's factory and started assembling their first machine. When they brought it to the Euro Mold trade show in Frankfurt the next year, it was the first laser-powered, metal-melting 3D printer on the market.
This 3D printed skull implant was produced on a Concept Laser machine. Image credit: Laurent Lantieri.
But the technology was so new - the first machine generated five patents for Herzog - that potential customers didn't know what to do with it. 'We were so excited, but also so naïve,' Herzog says. 'We really had no idea how to sell it.' Still, Robert and Kerstin's father each bought a machine and so did the German luxury carmaker Daimler, which used it for rapid prototyping of auto parts.
Herzog and Kerstin, who were now married, hired salesman Oliver Edelmann, who'd sold Robert his stereolithography machine, to help with marketing. The company opened for business in the small Bavarian town of Lichtenfels and started developing new machines, small and large, capable of printing stainless steel as well as titanium, aluminum, cobalt and nickel alloys and other materials. Edelmann is now responsible for global sales at GE Additive.
The new machines proved to be useful. Kerstin's father and uncle, for example, used them to print intricate cooling channels in steel molds used for injection molding of plastics. 'They pumped cooling liquid through these channels, which couldn't be milled, and cooled the molds down as much as 30 percent faster,' says Daniel Hund, Concept Laser's marketing director. The 3D printed design dramatically increased mold turnaround and productivity without forcing the customers to spend money on a new injection-molding machine.
As the company grew, so did its offering of machines. By 2014, it was selling 100 machines a year and had received 65 patents and filed another 120 patent applications. A year later, Airbus and Laser Zentrum Nord used another Concept Laser printer to design and print a 'bionic' wing bracket for Airbus' latest A350 XWB passenger jet and make it 30 percent lighter, a feat that earned Herzog and two of his colleagues at Airbus the prestigious German federal president's prize in 2015. 'Bionic design allows you to adapt structures from Nature and find the most optimal solution,' Hund says.
Today, Concept Laser's M lab machine can print precise hip joint replacements and surgical tools. The company's giant X Line 2000R machine, the largest metal 3D printer in the world, can make entire engine blocks. In 2016, the company sold more than 150 , and Hund says 750 Concept Laser machines are in service worldwide. With GE Additive, these numbers will grow even faster.
Concept Laser and GE are taking the additive manufacturing gospel to more customers. GE Additive started opening Customer Experience Centers around the world - the latest one opened in Munich in December - where companies can explore the limits of the technology. 'It doesn't make sense to just adapt a conventional design for additive manufacturing and print it,' Hund says. 'You would leave a lot on the table. We will help you design it in such a way that it's lighter, has more function and combines 30 parts into one.'
Says Herzog: 'They will love it!'
A bionic concept design for an Airbus jet. GE is already printing jet engine parts, but in the future, planes could also be printed. Image credit:Airbus Operations
'Bionic design allows you to adapt structures from Nature and find the most optimal solution,' Hund says. Image credit: Laser Zentrum Nord GmbH and iLAS-Technische Universitat Hamburg-Harburg/Concept Laser.