The additive construction industry continues to lay its foundation. This time, a home has been 3D printed in Patchogue, N.Y., by a Long Island-based startup looking to drop the cost and danger of construction significantly.
To learn more about the firm, its technology and its plans, we spoke to Kirk Andersen, chief engineer for S-Squared 3D Printers (SQ3D).
From 3D Printing Plastic to 3D Printing Concrete
In 2014, SQ3D began as a manufacturer of desktop filament extrusion 3D printers. The company continues to make and sell its AFP-1728 and AFP-512 desktop systems, which go for between roughly $1,500 and $3,000. While SQ3D still ships about one printer a month, it began investigating the idea of additive construction about two to three years ago.
“We met with one of our current partners who wanted to, as we sometimes describe it, spit out a house. We wanted to scale up [our 3D printing] process and use concrete,” Andersen said. “It was kind of a crazy idea two to three years ago. Now we’re [moving] full force with it.”
According to Andersen, SQ3D’s central team has both the engineering and construction chops to tackle the additive construction space. On the construction side of the equation, Andersen has been a contractor for the past 10years, running a new construction and remodeling company. James Michel has been a residential and commercial general contractor for over 15 years, building more than 1,000 units, including multifamily homes.
Co-owner Robert Smith is a Master mechanic and machinist, having built many CNC machines and developed the company’s desktop 3D printers. He did this alongside his lifetime friend Mario Szczepanski, who has been an engineer involved in mechanical, optical and electrical systems for over 35 years.
Shifting from comparatively tiny plastic printing machines to larger-than-life-sized house makers isn’t as easy as one might imagine. For one, plastic components aren’t going to cut it for something capable of making a 500-square-foot structure in a matter of hours.
“The entire machine is made out of aluminum and stainless-steel construction,” Andersen relayed. “We’re using very accurate parts, linear rails. We’ve developed our own gear ratios to hold up the large gantry.”
The result is the Autonomous Robotic Construction System (ARCS), for which SQ3D has filed a patent. Due to the proprietary nature of some of the firm’s technology, Andersen wasn’t able to go into all of the specifics with regard to the extruder and cement mixture, except to say that a large volumetric mixer was required for the sheer amount and reactivity of the mixture, which cannot be made manually. The cement pump, too, has been modified.
SQ3D has also developed its own cement mix. As we’ve learned from other additive construction companies, the proper cement mixture is key to ensuring that the material does not flow so much that it cannot support the subsequent layers. The same is true for the drying speed of the cement, with quick-drying characteristics being necessary for support as well.
Unlike firms like WinSun, perhaps the largest and most well-known player in the additive construction space, SQ3D focuses on 3D printing entire structures on-site, as opposed to producing walls and other elements in a climate-controlled setting and then assembling buildings at the construction location.
SQ3D has also developed its own slicing software, which is used to convert a 3D model into printable toolpath code. The printing properties of cement are obviously different from molten plastic, requiring different extruding processes. The large-scale, industrial nature of the machine also involves movements that are wholly unique to the ARCS and cannot be directly extrapolated from a desktop plastic printer.
A 3D-Printed Home in Long Island
To call the structure that SQ3D fabricated at its headquarters in Long Island a “home” would be a bit of a stretch in that no one will actually be living there. In fact, SQ3D already took the structure down. In reality, the 500-square-foot building was a test case to see how well the layers would stack and the structure would hold together.
Ultimately, the test, the third and biggest large-scale structure to be produced by the firm, was a success. According to Andersen, the 3D-printed concrete structures have survived compression tests of over 6,000 PSI—double the standards required for traditional homes. He also assured us that, because the concrete is sealed, the structure would be fire- and waterproof.
Standards for additive construction still haven’t been introduced to the industry yet, given the nascent stage of the industry. Andersen predicts that in the next two years, standards will be introduced and SQ3D hopes to have a hand in the process. For instance, Andersen remarked that the firm aims to see its material infill pattern, which can have a significant impact on the structural properties of a 3D-printed object, trademarked.
Automating Construction
Having completed its first 3D-printed house, SQ3D will be offering its construction services as it works to further automate the additive construction process. Right now, the printing itself is largely automated. Next, the firm will try to make the cement mixing process occur automatically, possibly using a silo with integrated sensors and an attached pump.
In addition to making homes potentially stronger while using less material, SQ3D believes that, automating the construction process could reduce workforce injuries and fatalities. An automated system would only require a few engineers to watch the system, removing the need to put workers in the line of danger.
“Worldwide, about 3,800 deaths and about 700,000 injuries occur annually in the construction field,” Andersen said. “Those are real lives being affected. Having this whole process automated could prevent [some of those injuries and deaths].”
In addition to automation, SQ3D will be exploring various reinforcement techniques, such as introducing reinforcement fibers to the concrete itself. In the future, the firm may also look into geopolymers that could be used in place of concrete, which, if it were a country, would be the third largest emitter of carbon dioxide behind the U.S. and China.
The 3D-printed home is currently being evaluated by Guinness World Records to determine if the structure qualifies as the “largest house 3D printed on-site,” but SQ3D is already working on its largest print project, a roughly 1,800-square-foot permitted home, which Andersen said is sure to “shatter any 3D printing records.”
To learn more about S-Squared 3D, visit the company website.