The magic of 3-D metal printing

AMES, Ia. — Deep in the basement of an engineering building at Iowa State University, a tiny laser pings back and forth from the guts of a gargantuan 3-D printer, striking a thin layer of metal dust on a metal plate at precisely the right spots.

Within seconds, the outline of a pair of scissors begins to emerge as the laser continues its path back and forth hundreds and hundreds of times, melding the thin layers of dust brushed over the plate with an automated roller. Hours later, a perfectly formed pair of scissors is ready for snipping.

And scissors are one of the least interesting things created by this 3-D metal printer, which, experts say, is limited only by the imagination of its operator.

The $900,000 metal 3-D printer recently installed at Iowa State isn't all that different from the plastic 3-D printers that have swept through the worlds of traditional manufacturing and high-tech entrepreneurship. In fact, 3-D printing is becoming so ubiquitous that researchers have printed everything from edible pizza to models of human hearts to prosthetics for amputees.

But experts say metal 3-D printers like the one at Iowa State are poised to alter the manufacturing process, since the mammoth machines can help companies build prototypes and line-ready parts more quickly and cheaply. And without the traditional constraints of machinery encumbering the design process, 3-D printers can create parts that would be impossible with popular manufacturing methods.

"I spent 25 years learning how I can't make a part. There are a lot of limitations," said Chris Hill, who, after building consumer appliances, now works with the new 3-D printer on Iowa State's campus. "This particular process eliminates a lot of those limitations."

New tech in play in Iowa

Plenty of shared knowledge exists about the best ways to operate common machines such as lathes and mills. But when it comes to still-emerging technologies like metal 3-D printers, much of that knowledge remains proprietary within the small group of big companies using those machines, Hill said.

That's why ISU's Center for Industrial Research and Service bought the machine, to help Iowa's manufacturers learn more about what the industry calls additive manufacturing. While plastic 3-D printing has been all the rage in manufacturing and popular culture, Hill said much less is known about the metal versions.

Aside from speeding the design-to-market process, metal 3-D printers can create intensely intricate parts, such as molds with swirling cooling channels or parts erected in honeycomb patterns. Parts can be hollow, or include labyrinthine chambers because no drilling is needed.

"You simply cannot machine that," Hill said while holding up one part with curved cavities that was made on the machine.

Because of the hefty price tag, Hill said companies want to make sure 3-D metal printing is applicable for their business before committing the cash. ISU's machine was funded by CIRAS, ISU's College of Engineering, the Iowa Economic Development Authority and federal money.

CIRAS has worked for several months learning the machine and gauging its potential and limitations. Staffers have teamed up with some Iowa manufacturers and plan to pass on what they've learned.

"Let us make the mistakes, and we'll tell you about our mistakes," Hill said.

How it works

ISU's 3-D printer uses stainless steel dust to slowly build a part, one layer at a time. The machine can also build parts out of other metals, including chrome, titanium or aluminum. The machine rolls out a thin layer of stainless steel dust, and a tiny laser bounces off rotating mirrors to hit the metal fragments at the right spot.

"You're basically taking powder and using a laser to weld it into something," Hill said.

Each layer is 40 microns thick, thinner than the width of a human hair. It's common for a part to be built from more than 1,000 layers.

The 3-D printer has created complex parts that contain rotating parts — all built in a single go.

Mike Ralston, president of the Iowa Association of Business and Industry, was amazed by the machine's ability at a recent demonstration in Ames.

"I had no idea they could build parts inside of parts or parts that move," he said. "It's incredible."

The technology has the potential to transform the manufacturing process for many Iowa businesses, he said, especially small and medium-size manufacturers that haven't had access to 3-D printing.

"It will save a lot of time and a lot of money," he said.

Imagining the possibilities

While ISU's printer can take more than 24 hours to print some pieces, time savings are viewed as a major benefit of 3-D printers. Once a design is created, it can be stored indefinitely, and items can be printed, essentially, on demand, without the need to send off for molds or machining.

"Whether it's just-in-time inventory or doing a lot of prototypes, it makes it less costly to do things," said Brian Raymond, director of innovation policy at the National Association of Manufacturers. "Now all of that can be done with software and relatively inexpensive materials. Everyone from the small bolt-maker to the large automaker is leveraging 3-D printing."

Jim Johnson, chief operating officer at Frog Legs in Ottumwa, said his wheelchair parts company is intrigued with the new metal 3-D printer.

"Because of the technology, you can do things that other people can’t," he said.

Frog Legs recently started another company, Angstrom Precision Molding. And Johnson said he sees a lot of potential in driving down the cost of molds with 3-D printing.

"The main cost in getting a customer to get on with you is the price of the mold," Johnson said. "And a lot of people have gone to China because of that."

The two companies have been working with CIRAS to test the technology. So far, Johnson said, he isn't anywhere near ready to buy his own machine, but he is interested in gaining some access to a metal 3-D printer.

"We’ll have to wait and see the finish of the parts that come out and how well they hold up," he said. "This is kind of a proving ground for us."