Back in June of 2015, we heard about how Dutch 3D-printing firm MX3D was planning on printing a steel footbridge that would go across Amsterdam's Oudezijds Achterburgwal canal. Well, construction of that bridge is now complete – although it still has to actually be placed over the water.
To build the bridge, the company used four of its MX3D-Metal robots.
These consist of a robotic welding arm that lays down a blob of molten metal, then adds another blob on top of it once it's hardened, and continues that process until it's created an entire metal column. By controlling the point in space at which the welds are made, it's possible to control the orientation of the columns, even getting them to interlace with one another. No supporting materials are needed, and quite large structures can be created.
The finished bridge is 12.5 meters long (41 ft), and took six months to print. It's composed of 4,500 kg (9,921 lb) of stainless steel, along with 1,100 km (684 miles) of wire.
Originally, MX3D hoped to print the bridge on location, with the robots starting at one side of the canal and then building their way across. This turned out to be impractical, however.
"The Oudezijds Achterburgwal where the bridge will be placed is just a too busy place to print," the company's Oleg Vishniakou tells us. "There are a lot of pedestrians walking by every day so it would be hard to get a permit for it. Also you'll need 24/7 surveillance at the printing site to protect the robots."
The bridge will now be subjected to load tests in order to verify its structural integrity, before being installed at the canal.
Source: MX3D
If it lasts 400 years the embodied energy is minimal, if only 40 years, then it would be more efficient making it from hardwoods (new trees grow).
Randy