How can you print something larger than the printer itself? That’s the problem researchers Xu Zhang, Mingyang Li, Quang-Cuong Pham, and others set out to solve at the Singapore Centre for 3D Printing at Nanyang Technological University (NTU).
Their solution: setting the 3D printers on a pair of Ridgeback mobile robots, who work together to print different sections of the same part.
Amazingly, the robots work at the same time and in overlapping workspaces. In fact, the paper, published in August 2018, scars the first time a large concrete structure has ever been 3D-printed by multiple robots together!
Most 3D printing systems lack scalability:
Gantry-based systems—in which a cartesian robot moves inside a cage—are large and inefficient. To print a meter-long structure, for instance, you’d need a cage of at least 1 meter cubed. This significant external framework signifies you can’t build anything bigger than your system.
Robot-arm-based printers are rather more efficient than gantries, but they still take a long time to print anything, because a single print nozzle still hogs the entire print space.
Multi-robot systems like Minibuilders are not ideal for printing concrete structures, because the first layer of concrete needs to solidify before the climbing robots can proceed to print the next section.
As you can see, mounting 3D print nozzles on robot arms is nothing new. What’s different here is that the researchers attached the arm itself on a mobile base—allowing the print nozzle to move around in a bigger workspace—and they thought out how to get two robots to develop a structure at the same time.
The result is a scalable system: one that lets the user expose as many robots as needed to complete a printing task quickly and efficiently.
Why is this such a big deal? Because it overcomes a huge challenge to printing significant structures. With the old stationary system, the robot could only print within the area its arm could reach. To build bigger structures, you had to put multiple robots to work alongside each other.
With the new system, though, this size limit no longer applies. Since the robot can move about, you can create much bigger structures with just one robot.
Of course, there’s still a lot of work to do. The team wants to mix more sensors, explore better part-joining procedures, and create a motion-planning solution for multiple printing-while-moving robots.
And they won’t stop here. In adjustment with NASA’s 3D-Printed Habitat Challenge, their greatest dream is to develop robots that can build autonomously in severe environments—from the most isolated caves on Earth to the moon, Mars, and beyond.
This article is originally posted on roboticstomorrow.com