AREVO’s fully automated process facilitates the production of larger parts, making the 48-inch long, 36-inch high and 2.5-inch thick bike frame an ideal first application for the 3D technology. The company says that the direct energy deposition of carbon fiber filament enables less than 1 percent voiding in the manufacturing process. “We can print large structures that exceed aerospace grade requirements for primary flight structures,” indicates Miller.
Using standard G-code, the most widely used numerical control programming language, the part design is transmitted from Pathfinder software to the production cell. The manufacturing cell consists of a 7-axis robot and platform from ABB Robotics, a deposition print head with proprietary thermal management equipment (a laser), a cutting fixture, customized electronics and a vision system for in-situ inspection. AREVO designs and builds the deposition print head themselves.
The robotic arm positions and moves the print head, which then guides the filament deposition to create the 3D shape of the bike frame. The carbon fiber material can be placed in an infinite number of orientations, according to the company.
“For most 3D printers, the operator is laying down liquid material on top of a solid layer,” notes Miller. “The laser right behind the print head heats the PEEK thermoplastic so we’re joining melted PEEK to melted PEEK for tremendous adhesion strength in the inner layers of the part.” After the cutting fixture slices the carbon fiber filament, the robot repositions the print head for the next filament deposition instruction.
“The laser allows us to apply a lot of heat and deposit a lot of material very quickly,” Miller says. “On the flip side, we have to precisely control the laser to avoid burning the filament or degrading the structural integrity of the carbon fiber. Machine learning has taught the print head to see, via the visual inspection system, where and how much heat is being generated.”
The vision system monitors height, width and length. Inspecting the visual properties in real time allows AREVO to measure every layer within microns and automatically adjust via the software. “We hit the button and walk away,” says Miller.
Far beyond the world of cycling, AREVO’s partners are excited about the ability to fabricate economically viable large-scale thermoplastic composite parts by marrying CFRP with 3D printing. “We’ve had discussions for market applications including a commercial launch vehicle, construction equipment, automotive parts and oil and gas equipment,” Miller concludes.