Large-Scale Additive Manufacturing

(Image courtesy of KRAKEN Project.)

Here’s one problem with additive manufacturing as a production technology: many parts are simply too big to be 3D printed. Sure, there have been forays into larger formats for the aerospace and automotive industries, but these are typically standalone solutions working with a single material.

Where are the large-format, multi-material systems that will usher in the age of additive manufacturing?

In Europe, apparently.

(Image courtesy of KRAKEN Project.)

Meet the KRAKEN, a large-format robotic cell that combines additive and subtractive technologies for hybrid, multi-material manufacturing of parts up to 20 meters (67 feet) long. Essentially, it turns an entire building into a single manufacturing cell. The project was formed last year by 15 partners: six large companies, five SMEs, three research organizations and one industry association.

The KRAKEN project aims to address a number of engineering challenges, including formulating new polymers for large-scale additive manufacturing, developing new CAM algorithms for hybrid manufacturing—such as planar horizontal layer strategies—and defining commercial pathways (in terms of standardization requirements, market analysis, etc.) for KRAKEN’s implementation.

The basic components of the KRAKEN: (1) Additive metal equipment. (2) Additive polymer equipment. (3) Subtractive manufacturing head. (4) System controller. (5) High-level control interface. (Image courtesy of KRAKEN Project.)

To give one example of how these challenges are playing out, KRAKEN is currently utilizing an epoxy- or polyurethane-based thermoset resin that can be tuned for properties like ease of dispensing, sag resistance and wetting out between layers. The resin can also be formulated for polymer-on-metal or joining, creating an interface layer on the polymer for arc-wire processes.

The project has already been used in several demonstration cases, including waterproof covering modules for tunnels with integrated electrical conduits and a body-in-white for the Alfa Romeo 4C.

Sample KRAKEN parts combining metal and polymer additive manufacturing. (Image courtesy of the author.)

ENGINEERING.com had the opportunity to speak with Berta Gonzalvo, research director at the AITIIP Technology Center in Spain, which is leading subtractive operations and integration on the KRAKEN Project.

Is KRAKEN still in the proof-of-concept phase, or is it being used for production parts?

Both. There’s still a lot of experimentation happening, with new approaches and evaluations of different materials at this large scale for products, tooling and molds. At the same time, we’re offering technical services to companies to develop their products and tools using this system.

How does the KRAKEN switch from additive to subtractive operations, or vice versa?

The system works like a CNC machine: you have a tool magazine and a robot to change the heads. So, you can go from extruding polymers to extruding aluminum by changing the tool. The same goes for subtractive operations, like milling: you just change the head.

What are the current applications for the KRAKEN?

Our previous project—MEGAROB—was focused on two main applications: blades for wind turbines and structural elements for construction. KRAKEN can be used for these applications as well as aeronautics, transportation, anything that involves large parts.

Can the system conduct inspections, say by mounting a laser scanner on the robot?

Yes, it’s certainly possible to do that. Right now, we’re using the laser tracker mainly for positioning, but it could also be used for inspection and quality control. We can even include this device in the working area as another element that would be in communication with the whole system.

Where do you see this project going over the next few years?

Well, some of the results are ready to use and are in commercial applications now. A lot of companies, both large and small, are coming to our facility to test proof-of-concepts for their specific application. I’m very confident that by next year we’ll see this system up and running at other companies.

For more news from IN(3D)USTRY – From Needs to Solutions, check out The Airbus Roadmap to Additive Manufacturing.