It looks like something Spiderman might have built – a bike made of strong, silvery webbing somehow holding together tires, seat, and handlebars. In actuality it was created by a group of Dutch college students – not superhuman, perhaps, but ingenious all the same. Harry Anderson, Stef de Groot, Ainoa Areso Rossi, Sjoerd van de Velde, and Joost Vreeken are all students in the engineering department at the Delft University of Technology (TU Delft). Their three-month research project culminated in the Arc Bicycle – the first-ever metal bicycle to be produced using a 3D printing and welding process.
The process is known as Wire and Arc Additive Manufacturing, or WAAM. It’s a specialty of MX3D, whom you may remember for their 3D printed steel bridge project. They’ve developed a fascinating technology that involves using giant, multi-axis robotic arms as 3D printers, allowing for metal and resin materials to actually be printed in mid-air, without any need for support structures. MX3D invited the student team to design something that would demonstrate their technology as part of a research project into the WAAM method.
“3D printing has exploded in popularity in the last decade but for those wanting to print medium to large scale objects, there are still significant limitations in the technology,” said Anderson. “This method of 3D printing makes it possible to produce medium to large scale metal objects with almost total form freedom.”
The project was also a way for MX3D to test a new print software they are developing with their partners for the bridge project. There were a few snags with how the software’s algorithms handled the bike’s geometry, but after tweaking the software a bit, things ran smoothly; the frame began to take shape bit by bit as the robotic arms simultaneously deposited and welded the stainless steel material. As the bike came together, it looked too fragile to support a person’s weight, but appearances are deceiving.
“It was important for us to design a functional object that people use everyday,” said de Groot. “Being students in the Netherlands, a bicycle naturally came to mind. A bicycle frame is a good test for the technology because of the complex forces involved.”
That test proved to be successful, as the completed bike was taken for its first test ride around the city of Delft. Not only did it easily support the weight of its riders, but it made for a pleasant ride, handling the cobblestone streets of Delft with ease and gliding through sharp turns. The bike weighs about the same as a typical steel bicycle, about 12 kg.
The Arc Bicycle made its public debut at a university science fair. Due to a few delays, the construction hadn’t been entirely completed at that time, but it gained a lot of attention nonetheless. Visitors to the students’ booth were intrigued by the bike’s unique method of construction, and were incredulous that a stainless steel bicycle could be so lightweight. According to the students, the bike is “primarily a concept bicycle” but they hope that others will take note of the project and build on their research for future 3D printed bicycles. This project, along with the MX3D bridge, should certainly draw some attention to the WAAM process and, in particular, MX3D’s multiple-robotic-arms method of printing, which looks to have major potential for manufacturing. If you’d like to read about the Arc Bicycle’s development in more detail, you can take a look at the students’ blog; below, you can see it for yourself. Share your thoughts on this process in the 3D Printed Metal Bike forum over at 3DPB.com.