Ohio State debuts state's largest 3D printer

More than 200 people gathered in a former Ohio State University horse arena Thursday to witness what some believe is the future of construction.

They watched as workers demonstrated the state's first large-scale 3D construction "printer," a machine that builds homes and other structures one automated layer of concrete at a time.

Those involved say the process can be used to erect buildings faster, with fewer workers and less waste than conventional construction, and can play a key role in addressing the nation's housing shortage.

"You've got people making $50,000, $60,000 a year who can barely afford a place to live," said Stephen Davis, the chief development officer with Pantheon Innovative Builders in Youngstown. "We have to figure out a way to build faster."

Pantheon owns the printer, called BOD2, which was made by the Danish company COBOD (Construction Of Buildings On Demand), the largest manufacturer of 3D construction printers in the world.

More:3-D-printing industry more sophisticated, nimble? Copy that

Pantheon delivered the machine to OSU in January in a partnership with the university's Center for Design and Manufacturing Excellence to research how to best use 3D technology (called "additive manufacturing") in the real world. OSU officials hope to use the machine and a team of experts from different departments to become a national authority on building with 3D printers.

"We're really good at printing metals and really good at printing plastics," said Ben DiMarco, an additive manufacturing technologist at CDME who is involved in the project. "Why not print with concrete?"

DiMarco said he hopes the printer can produce a small building somewhere on campus in the next few years.

The COBOD printer works like other 3D printers: material is extruded from a moving nozzle, layer upon layer, guided by a pattern programmed into the machine.

Instead of plastic and metal, the COBOD "prints" with concrete. Each swipe of the arm deposits another layer of concrete, allowing a wall to gradually rise. The walls Thursday were made of two bands of concrete, each about 3 inches thick, several inches apart, allowing insulation to be pumped into the cavity.

Windows, doors, flooring, roofs, mechanicals, countertops and other finishes are manually added after the walls are set. The BOD2 can "print" buildings up to 30-by-30 feet, though it can be expanded to produce buildings up to 75-by-75 feet.

More:New Albany grad's Form5 Prosthetics 3D prints face shields to fight coronavirus

OSU's machine uses a blend of Quikrete as its building material, but DiMarco noted that one advantage of 3D printed buildings is that they can use local material.

"The long-term future is to use locally sourced materials to make your own mix — sand, aggregate, things like that — and there's research going on around world to use other materials such as fly ash, hempcrete or local clay," he said.

Asked Thursday how much a 3D printed home might cost, Pantheon CEO Ryan Kelly said no one really knows yet, but he estimated it could be 40% less than conventional construction.

Constructing buildings with 3D printers has its limitations. It's difficult to build higher than one story, roofs must be manually installed, and printers must be powered and set firmly on concrete footers.

Such challenges have made 3D printed buildings largely a novelty so far in the U.S., although some companies, such as the Texas-based Icon, in a partnership with the huge homebuilding company Lennar, have built several homes with the technology.

Dale Nehls, a representative of Quikrete, said the company's material has been used to "print" six homes in Virginia, Texas and California, including one two-story, 4,000-square-foot home in Houston. He and Vincent Albanese, COBOD's North American manager of strategic partnerships, said they expect the technology to become far more common.

"I think you'll see this, not in a year, but in years to come," Nehls said. "There's a use for this. ... It's the future."

[email protected]

@JimWeiker