More than three decades later, Herzog’s fascination with shiny objects endures. He is the founder and CEO of Concept Laser, a pioneering maker of 3D printers whose machines — including the world’s largest industrial printer for metals — can print delicate jewelry and dental implants as well as massive engine blocks for trucks. In 2016, GE acquired a majority stake in Concept Laser, which now is part of GE Additive, a GE business dedicated to supplying 3D printers, materials and engineering consulting services.
Herzog, 46, grew up in Bavaria, a state that’s so obsessed with engineering, mechanical engineers alone account for 17 percent of its workforce.
But Herzog’s family was cut from a different cloth. His grandparents owned a fashion shop in Munich, which they passed to his mother, and his father had a small construction equipment business. “I think I got my business acumen from my mother’s side and my technical side from my father,” Herzog says.
Like his father, who designed and built the family home himself, Young Frank was an avid DIY-er. 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.” More interested in building than book-learning at the time, he dropped out of high school and spent the next three years as a factory apprentice, soaking up all he could about manufacturing. “I learned to drill, work with a lathe and a milling machine,” he says.
The experience awakened in him a yearning to understand manufacturing more deeply, so returned to school, earned his high school diploma and enrolled at Coburg University, a small technical school near Bamberg. There, he studied mechanical engineering while working as a bricklayer on the weekends.
Then one day, Herzog spotted Kerstin Hofmann in the lecture hall, and like metal colliding with metal, sparks flew. The engineering classmates started dating, and Kerstin, whose extended family owned several factories and plants around Bamberg, suggested that Herzog leave his masonry job to work for her father, an invitation he declined. “I felt I would be too exposed as a possible future son-in-law,” he laughs.
In what turned out to be a life-changing compromise, Herzog instead joined a nearby prototyping shop owned by Kerstin’s uncle, Robert Hofmann. 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.
Many 3D printers and other additive manufacturing machines grow complex parts directly from a computer file by fusing together layers of raw material. Herzog theorized that if he replaced the stereolithography machine’s UV light 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. The results weren’t encouraging, however. 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. The state-of-the-art solid-state laser she’d purchased for her master’s project emitted a continuous, low-frequency light beam that might be perfect for printing stainless steel parts with uniform structure.
Herzog borrowed the laser, installed it above his 3D printer and hooked it up to commercial software to control its movements. With his thesis deadline looming, he slept beside the machine so he could address any glitches immediately. “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. Several nights later, 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.
His diligence 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: Frank and Kerstin had to do it in two years because the brothers needed the money for other investments.
The couple 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.
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 by that point 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.
The company continued to grow, and 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 a 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 printers , and Hund says more than 750 Concept Laser machines were in service worldwide in 2017. With GE, these numbers will grow even faster. The machines, for example, already working inside GE Aviation's Additive Technology Center in Ohio, which might easily be the world’s largest and most advanced 3D-printing facility and development center.
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 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!”