The Kraken, reported to be the world’s largest and most accurate multi-material Additive Manufacturing machine and the result of a three-year EU-funded project, was officially released at the project’s final conference at the Aitiip Technology Centre, Zaragoza, Spain, this September. The hybrid system integrates both additive and subtractive manufacturing technologies, with a maximum working area of 2000 x 800 x 600 cm.
Coordinated by Aitiip, the research project behind the Kraken was supported by the Horizon 2020 EU programme and saw fifteen partners collaborate on its development. During the conference, which welcomed 120 attendees, the project’s partners presented early results and expressed their aim to revolutionise the manufacture of large parts with the production quality and efficiency the Kraken reportedly offers.
The Kraken uses Wire Arc Additive Manufacturing (WAAM) to process aluminium, and incorporates a bi-material resin extrusion system. An arc spray metallisation process also enables metal Additive Manufacturing on top of an existing polymer part. The system’s subtractive capabilities allow for cutting, sanding and polishing operations.
All of the Kraken’s operations are controlled by a laser tracker, which monitors the position of the working head 1,000 times per second, correcting its position automatically. The system also incorporates two types of cameras and artificial vision systems to control deposition flows and for the subsequent verification of the piece via three-dimensional scanning.
“Due to the integrated Leica Absolute Tracker, parts manufactured by the Kraken machine can be digitised in 3D and checked against the CAD design to verify the quality of manufacturing over the full volume of the machine, even fully automated if needed,” commented Markus Steiner, Product Manager – Software and Connectivity – Portable Products, Hexagon Manufacturing Intelligence.
The possibility of building high-quality, large metal and resin parts by means of Additive Manufacturing has raised the interest of much of the industry. Hybrid lining panels for road tunnels of 3 · 1.2 m have been manufactured for Acciona, one of the consortium partners. Thanks to the combination of resin and metal, electrical connections can also be produced much more easily.
To demonstrate the Kraken’s applications in the automotive sector, a mock-up of one of Pininfarina’s latest car models has been produced to validate its design. The built piece has a size of 2.2 x 1 x 0.6 m and a weight of 250 kg.
These are some of the real applications that have already been tested, although the sectors that can benefit from this system are thought to be much broader, since it offers low-cost, high-quality, fast and efficient alternatives for the die and mould sector and for the tooling of large parts.
José Antonio Dieste, Aitiip researcher and project coordinator, stated, “The machine is ready for the market, it has been tested in a real manufacturing environment and project demonstrators have been validated by the companies in real conditions. We can now deliver or install Kraken cells according to client demands.”
“Guaranteeing accuracy in large workspaces of 100 m2 is a challenge that Kraken has solved by integrating real time laser tracking technologies within the closed loop control of the robotic system,” explained Francesco Crivelli, CSEM SA, who is responsible for designing the control algorithms and implementing the software. “Thanks to this method, tool precision can be assured down to 0.1 mm.”
Further information about the Kraken system and the collaborative is available via the project website.