With Robots, Additive Manufacturers Create Larger Parts and Add Precision
| By: Laura Moretz, Contributing Editor
|The Arevo AQUA composite printer. Lights-out manufacturing of composite parts of any size (from tennis rackets to bike frames).
Photo Courtesy: Arevo Labs
Robots increasingly facilitate additive manufacturing, enabling efficiency, precision, and the size of created parts. In this growing field, both long-time industry leaders and start-up companies improve additive manufacturing results with robots.
Two companies that make single-piece components with robotic assistance are Arevo, a Silicon Valley start-up, and FANUC America, the No. 1 robot maker in the U.S., and a division of the Japanese FANUC. These are two of many companies that innovate in the field, working to create larger parts and eliminate weak joints.
In contrast, Physik Instrumente, a German company with U.S. headquarters in Auburn, MA, drills down for sub-micron precision in its parts, which in turn allows additive manufacturers greater precision in their additive manufacturing processes.
Maximizing Automation from the Start
Arevo, launched in 2013 as a start-up, has developed direct digital technology to create strong, lightweight parts on demand for a range of customers. Wiener Mondesir, a co-founder, and chief technology officer of the Silicon Valley company, described how its proprietary
software, Xplorator, allows the creation of light carbon fiber composites. His partners, veterans of other start-ups, agreed with him that the “software is really going to unlock a lot of what we’re able to do if we have software that can look at real-world loading conditions and come up with the right fiber orientation.”
Xplorator opened the door to the founders’ second objective, which was to eliminate hand-built procedures. “There had to be a way of doing this in an automated way to give you freedom,” Mondesir said.
In 2014, patents were expiring and the maker movement was in gear, he said. Arevo’s next step was to find the best way to build, using software modeling. 3D printing was key to building composite structures. “If we tailored it with the software, we could understand how to orient fibers and build the kind of structure that could meet any kind of predetermined material property or part property. So we built a machine essentially to do that.” The latest iteration is the Aqua 2 carbon fiber printer.
|Smooth Surface Finish After Post Processing
Photo Courtesy: FANUC
Mondesir said that the third important thing for Arevo’s development was its materials. 3D printing was first used for prototypes, but now the goal was to print components for production. “In production, there’s a need to understand how that part is going to perform in the real world as far as quality, consistent repeatability, accuracy, dimensional tolerance, and quality assurance. So there was a process problem that we needed to address. As a startup, you know, this was a lot to bite and swallow in one go,” he said. “We were ambitious and decided we wanted to control our destiny” by spanning design to production.
After Arevo created its first prototypes, it added ABB robots to provide multiaccess capability and the ability to orient in 3D space. Arevo’s use of carbon fiber composites allows a short turnaround from concept to a functional product. Its industrial-grade continuous fiber 3D printing system can print parts of up to one cubic meter volume.
Key Wins Along the Way
Arevo accepts orders from clients for parts and continues to develop new uses for carbon fiber composites, hosting monthly hackathons. From these hackathons, it has developed a well-received continuous carbon fiber tennis racket and furniture. In a separate initiative, Arevo developed a carbon fiber bicycle this year, the Superstrata, which began as a technology and product demonstration, but also has an exciting market. Its frame is a single piece of carbon fiber designed with Arevo’s Xplorator and printed on its Aqua platform. Each bike is custom-made to accommodate different leg lengths and body sizes.
Arevo is expanding its printing capacity from five Aqua machines at its farm in Milpitas, CA, by adding fifteen Aqua machines to a new farm in Vietnam. The farm in Vietnam is planned to grow to 100 machines. “It’s probably the only country open and speeding ahead right now in this COVID time, and it just so happens our CEO is from there.”
Fast redesign and turnaround are key. Mondesir said, “If you are able to move at this speed, you have the ability to change on the fly, and if something isn’t working, you make the change and continue. Automation enables all of this.”
Metal Wire for Additive Manufacturing of Large Parts
FANUC America Corp., based in Rochester Hills, Mich., is the No. 1 manufacturer of robots in the U.S., with a broad range of customers in the automotive, aerospace, agricultural equipment, and many other industries. Its parent company, FANUC, was founded in Japan in 1956.
FANUC America also supplies the aerospace industry with robots that perform additive manufacturing or 3D printing by working with partners that specialize in the integration of robots for building automated systems.
Recent advances in weld-wire additive manufacturing (WAAM) allows the creation of large parts with robotic assistance. Mark Scherler, a general manager of FANUC America, said the weld-wire process creates metal parts suitable for automobiles and airplanes.
|Operator Monitoring WAAM Process Performed by Cobot
Photo Courtesy: FANUC
“When an extrusion head can be placed on a robot, it goes from having a three-axis system to a six-axis system,” Scherler said. “So obviously, we can manipulate the head quite a number of ways with robot models that provide a larger envelope than what standard additive systems allows you to do. So you can build bigger parts.”
Scherler said he is excited by new possibilities allowed by the additive process, including flexibility in design, reduction in weight, and designs that are more efficient to build. “It opens up a lot of new ideas for manufacturing.” Only some of FANUC’s 100-person research and development team focuses on additive manufacturing, but the focus has grown.
For example, Scherler said, “A number of years ago, I wasn’t really thinking about additive using weld wire. But that process is certainly mature enough that people are using it. And being able to put that on one of our robots and building a part is pretty exciting.”
|Arevo DED (direct-energy-deposition) head. Enables high-quality composite parts at scale.
Photo Courtesy: Arevo Labs
FANUC’s robots are flexible and easy to program. Manufacturers can use them for multiple applications, choosing from a line of variously sized robots. “Depending on how big of a part you need to build or how big of an extrusion head you need to carry, we have a robot that is able to handle it.”
In addition, FANUC embraced the cobot concept, which allows a human to interact with or stand near a robot as it works, without the standard guarding that separates robots from humans. FANUC has demonstrated the cobot at shows such as FABTECH, performing WAAM for small metal parts typical for the aerospace industry. In production manufacturing, such parts can be three or four feet tall.
Honing Precision for Additive Manufacturing Systems
Physik Instrumente (PI), a German company with a US presence and US headquarters in Auburn, Mass., focuses on motion systems that are enabling the creation of the highest precision parts for additive manufacturing systems. Matthew Price, the technical manager of precision automation for PI, says that PI has a team of 40 to 50 people works to create the more precise parts for their customers dedicated to additive manufacturing, often with features measured on micron and sub-micron scales.
|Custom Gantry for laser machining of PCB boards and electronics components.
Photo Courtesy: PI
Price said, “We don’t sell additive manufacturing systems. We sell to people building them.” The result of PI’s work is visible. “If you held
up a part and you looked at it and you saw defects, we probably wouldn’t be involved in the manufacturing of a part like that.”
PI has fully featured software and hardware complements that contribute to additive manufacturing systems. “Our primary work is focused on making our automated platforms, precision stages, motion systems, and software to support laser processes, dispensers, and extruders. We have some proprietary processes that help us to optimize, especially with material-dispensing applications. But our core is making hardware and software used to build advanced 3D printers or advanced additive manufacturing systems.”
|Additive manufacturing in the nanoworld. The TERA-Fab™ desktop printer for nanostructures. It employs a compact 3D piezo nanopositioning stage (model P-611 PI NanoCube) to move the substrate under the beam pen array.
Photo Courtesy: TERA-print
PI often works with major university research centers and commercial companies in the private and public sectors that use features that are extremely small. “They’re starting to get to sub 50 microns and sub 30 micron-type features. Then there are specialized laser processes achieving much higher feature sizes still.” He points to photopolymerization as state-of-the-art technology. “Two-photon polymerization can resolve down to sub hundred nanometers.”
PI has acquired majority shares in ACS, which makes motion controllers. “When I speak about us, I’m speaking about us together.”
The segment of additive manufacturing for which precision is increasingly important can be seen at shows like rapid + tct, he said. “Seeing an idea built in front of you — it’s very cool.”
PI’s goal is to continue to enhance the performance of manufacturers that use robots to perform additive manufacturing. “We’re not going to have the kind of materials/process expertise they have. They will never have the kind of precision automation expertise we have on our side. And when you put the two together, then I think that’s how you really get the best result.”