At the end of 2017, Additive Engineering Solutions (AES) took delivery of a second “big area additive manufacturing” (BAAM) machine and two CNC machining centers: a large-format, Thermwood 5-axis router and a traditional 3-axis HAAS vertical mill. Just one year ago, the only piece of machinery at the Akron-based contract manufacturer was a lone BAAM printer.
The BAAM printer is a product of Cincinnati Incorporated (CI), developed in partnership with Oak Ridge National Laboratory (ORNL). It is an adaptation of CI’s gantry-based CO2 laser cutting system (including the machine frame, motion system, and control) that has been fitted with an extruder and pellet feeding system.
The most notable features however, are the print size and feed rate: the largest of which is 960 ft3 with an 80 lbs/hour feedrate. That rate is approximately 500 times faster than existing additive machines.
“We talked to a lot of people who are talking about printing big parts. BAAM is about as big as you're going get at the moment,” said Clark Patterson, senior process engineer at AES at the ADM Cleveland Expo earlier this month.
BAAM was designed to allow additive manufacturing techniques to be used for production manufacturing. Beyond the build capacity and print speed, BAAM was designed with an open architecture regarding thermoplastic print materials, meaning lower print costs and thousands of polymer options.
Although material options are nearly endless, AES regularly opts to run glass-filled or carbon-filled materials to address warping and shrinking issues—which scale with the size of the print. Metrology solutions are also very important in the large format additive process because currently available simulation software is not capable of modeling print warping or shrinking at BAAM-scale.
While AES wasn’t expecting to double their additive manufacturing capacity so quickly, according to Andrew Bader, head of business development at AES, the acquisition was in line with the company’s recent growth. AES is the only manufacturer to operate BAAM printers for contract clients.
Of the 13 BAAM printers currently in existence (at the time of writing), four of them are owned by research facilities; two at ORNL, one at the National Institute for Aviation Research at Wichita State University, and one at the University of Texas at El Paso. The other seven machines are privately operated by Textron Aviation, Lockheed Martin, SABIC, Local Motors, and TSN Security & Telecom of Mexico.
AES has focused its efforts at manufacturing large format tooling—using the BAAM printers to produce near-net shapes with pelleted polymers, then machining the shapes, sanding, and coating them.
“As far as large format additive manufacturing goes, about 80% of the applications out right now are for some form of tooling,” said Patterson.
ORNL even won a Guinness World Record in 2016 for the largest solid additively manufactured tooling component, used to secure and stabilize a Boeing 777X composite wing skin for drilling and machining.
And more companies are entering the BAAM playing field. Thermwood, based out of Dale, Indiana, is developing a series of three similar machines that will go online later this year. Compared to the CI BAAM printer, the Thermwood Large Scale Additive Manufacturing (LSAM) machine is has a larger print area and extruder. Thermwood claims that the current print speed is 140 lbs per hour and plans to increase that rate.
Beyond tooling, the next focus for large-scale additive manufacturing for the aerospace industry is the fabrication of titanium components, according to researchers at ORNL and aerospace industry representatives. When considering the trade-off between printing titanium components and machining them from billets, the cost difference increases immensely with part size.
With Boeing and Oerlikon’s announcement in February to partnership to standardize metal additive processes and materials, these technologies may soon intersect.Continue reading »