3D Printing Four Small Houses in Four Days

3D printing small cement houses. (Image courtesy of COBOD.)

Denmark-based COBOD and PERI recently 3D printed the walls of four houses in four days at the recent bautec 2020 exhibition. Over the course of four days, this tour de force demonstration was viewed by thousands of visitors and attendees in Berlin. To be exact, the company printed walls for 3.5 houses and two bautec logos at a rate of eight square meters per hour.

COBOD is one of the most promising construction-scale 3D printing companies, and together with PERI, it set out to demonstrate in real time an alternative to traditional methods used in concrete construction. In traditional construction, lead times are difficult to predict and control, and there are off-site transportation issues and on-site safety issues. The whole process is often very wasteful to global ecology. Civil engineers use casting or precast procedures on the jobsite to make structural objects that support bridges, homes and buildings. The materials are generally Ordinary Portland cement. Alternatives to these methods have been widely publicized in trade press and other publications, but COBOD and PERI are the first to demonstrate the 3D construction printing of a house in real time—on full display in front of 30,000 people.

Using one of COBOD’s BOD2 3D construction printers, COBOD and PERI printed from 9 am to 5 pm during the exhibition. The goal was to demonstrate the robustness and reliability of their 3D construction scale house printing. On the first three days, the group successfully printed a small house. On the last day of bautec, managers of the exhibition requested that COBOD and PERI print out some bautec logos, which they did.

COBOD’s BOD2 printer is modular by increments of 2.5 meters and extends to 10 meters in height by 15 meters in width. The length of the BOD2 extends indefinitely, or as long as is needed. It prints at a rate of 100 centimeters per second. Limited by the confines of an exhibition setting, COBOD and PERI printed three-and-a-half bedroom houses with walls of about 4 meters by 4 meters at a slower setting of 25 centimeters per second. Part of the reason for a slower setting was to be in compliance with the EU machine and robotics directive. The directive requires that a safety fence be erected around the printer if the machine will be printing at its highest and most efficient speed. Opting out of a fence for exhibition purposes, COBOD and PERI chose an open, fenceless display with the BOD2 running at the slower speed setting.

Bottom Line

Henrik Lund-Nielson, CEO of COBOD, stated that the company achieved its objective at the exhibition, but that the company’s goal is to print at a speed of 20 square meters per hour. At this rate, COBOD’s printer could print a larger house than the one printed at bautec in 24 hours.

Click here to see four time-lapse videos of the BOD2 3D printer as demonstrated by COBOD and PERI.