Welding robots complete 3D-printed steel bridge

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At the airport in San Francisco, on our way to discuss with our first main sponsor Autodesk their involvement in MX3D, we brainstormed about what the ultimate poster project would be for showcasing all of the facets of our technology. We reached the conclusion that a bridge over one of the old canals in Amsterdam would be a fantastic metaphor for connecting the technology of the future with the beautiful city’s past in a way that would reveal the best aspects of both worlds.

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It would look like it defies gravity; layer by layer we deposite metal that solidifies until the bridge is ready. The bridge project, to a large extent, was a learning process; wherein we were unaware how long it will take, but we are certain we can develop the software and hardware to make this project happen. In any case, it was a great adventure and we are bound to discover new techniques. Autodesk, too, was thrilled to come aboard, and the project was born during June 2015.

October 2015 marks the official launch of the Bridge Project. A big thank you goes out to the City of Amsterdam for becoming an actual customer of this unique bridge. And thank you to Elderwoman Kasja Ollongren and CEO of Heijmans, Bert van der Els, for opening our new workshop. It has been great to add ArcelorMittal, ABB Robotics, Lenovo and Air Liquide to our team!

The final location was set in December 2015, upon the crossing of the Oudezijds Achterburgwal and the Stoofsteeg. In other project-related news, we are proud to add Plymovent and Oerlikon to the team! And thank you Leap3D for making this scan!

We finalised the design at last during May 2016! The initial design concept was focused on a very pure application of topological optimization. This particular technique was employed extensively early on in Joris Laarman Lab’s pioneering Bone Furniture collection. The software is programmed to reduce the required material to a minimum when generating the most efficient shape for a specific task – just as a bone will optimize itself in nature. The Bridge design employed Autodesk’s Dreamcatcher software in collaboration with the engineering expertise of Heijmans.

Challenges

The modern world of optimisation software and 3D printing, clashed with the traditional world of typical construction engineering. The engineering software used to address the various functional, and safety requirements could not handle our complex geometry. Additionally, there remained many unknowns yet to be taken into account; amongst other factors. It was unclear how much stress the medieval canal walls could withstand and it also turned out to be near-impossible to define the material properties of the printed geometries. This means, we have to start all over again… Basically, we had to reduce complexity and avoid tension stresses as much as possible. Hoping to make this happen quickly!

Solution

After a serious setback, we were back on track at last. In order to reduce complexity, we employed an entirely new approach. In November 2016, Arup joined our rockstar team and we began discussing a sheet-construction approach rather than the previously-attempted one centred around volume optimization. The benefits of the sheet concept were that it works primarily with compression forces using stress analysis software to generate force lines through the object.

A highly detailed 3D scan demonstrated that the bridge heads are not entirely parallel. As a result of this new found information, we chose to give the bridge an asymmetrical shape, in-plan. This increases the dynamic shape and allows showing that our proprietary technology is not bound by traditional, symmetrical forms. By making the entire bridge design parametric, the design adapts automatically with every design iteration; believe it or not, we could even make changes to the design after the robots start printing!

The final design was finished in February 2017!

After a challenging 18 month-long process of engineering, designing, re-engineering, re-designing, discovering the world behind permits, safety measures, canal wall renovation, re-designing, programming, fundraising, test printing, re-designing and re-programming, the actual printing of the bridge finally started during March 2017. We are printed large parts of roughly one metre, which were then assembled together after they’ve been printed. The initial production pace was fast enough to finish by early 2018 – exciting times!

The first tests with the robot printing in-situ were promising. We managed to print a nice part horizontally; but there were still many issues to resolve. Soon, we attempt to move the robot on the bridge and allow it to continue to print.

With close to a third of the bridge printed at the time of writing, we were well on track to be finished printing early 2018. By now, we’ve also mounted a robot directly on the bridge. What a great moment!

At Present

In April 2018, the full span of the bridge has been finalized, 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.

The bridge will now be subjected to load tests in order to verify its structural integrity, before being installed at the canal.

MX3D Bridge

 MX3D is 3D printing a fully functional stainless steel bridge to cross one of the oldest and most famous canals in the center of Amsterdam, the Oudezijds Achterburgwal. We equip typical industrial robots with purpose-built tools and develop the software to control them. The unique approach allows us to 3D print strong, complex and graceful structures out of metal. The goal of the MX3D Bridge project is to showcase the potential applications of our multi-axis 3D printing technology.

The Bridge is designed by Joris Laarman Lab,  Arup is the lead structural engineer, ArcelorMittal provides the metallurgical expertise, Autodesk assists with their knowledge on digital production tools, Heijmans is our construction expert,  Lenovosupports us with computational hardware, ABB is the robotics specialist,  Air Liquide & Oerlikon know everything about welding and lastly, Plymovent protects the air our employees breath whilst AMS and TU Delft do invaluable research. Gemeente Amsterdamis the first customer of our collaborative bridge building department.

 

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