While research is ongoing to determine just how unhealthy 3D printing fumes are, there are also a lot of ways that the technology is actually environmentally friendly, from recycled filaments and new ways of manufacturing solar panels, to helping save endangered species and reducing carbon emissions. This last is the focus of a proof-of-concept project developed by Autodesk research scientist Andreas Bastian at the company’s Pier 9 technology center in San Francisco. In an effort to “bridge the gap” between 3D printing and metal casting, he’s created a lightweight frame for an airplane seat, which could not only reduce carbon emissions, but also save airlines a lot of money.
Autodesk has used additive manufacturing and generative design to help airliners reduce carbon emissions, fuel consumption, and weight before: in 2015, the company collaborated with Airbus to create a 3D printed airplane cabin structural component. Once the dividing bionic partition, currently undergoing FAA testing, is deployed across the production backlog of Airbus A320 jets, it’s estimated to drastically reduce carbon emissions: equal to removing 96,000 cars from the road.
An algorithm in Autodesk’s Netfabb software was used to produce the geometry for Bastian’s aircraft seat frame, which would work in any standard commercial jet. The goal was to keep the frame as strong as the original, but make it much more lightweight; using lattice and surface optimization, the software was able to design a complex structure that will make the aircraft seats so lightweight that the need for jet fuel is majorly reduced. However, conventional manufacturing methods would not be able to create the complex geometries that are often used with 3D printing technology, and the cost of 3D printing at scale is not yet at a point where it is competitive with traditional production methods.
“While additive manufacturing holds great promise for the future of manufacturing, it’s still very new for many product developers,” said Bastian. “Casting, by contrast, has been around for millennia and is incredibly well understood. There are hundreds of thousands of engineers, foundries, and factories with deep expertise in it. That’s one of the reasons I am looking for a bridge between the two.”
Andy Harris, part of Autodesk’s advanced consulting group, worked with Bastian on the seat frame project.
“We can generate these incredible high-performance designs, but we had to look beyond direct metal additive manufacturing for this project,” Harris explained. “The size and cost just wouldn’t work for fabricating this part.”
While there are several metals used for 3D printing, the casting process can be completed with thousands of metals and composites. Also, even using Autodesk Project Escher technology, 3D printing volumes are typically just a few cubic feet, while casting can work with huge objects. So Bastian combined the two technologies: positive molds for the seat frames, containing the lattice geometry, were 3D printed in plastic, in order to save money and time, and were next used to make affordable, ceramic casting molds.
Since Pier 9 is not equipped with molten metal investment casting capabilities, Bastian worked with Michigan-based foundry Aristo Cast (if you’re a Disney fan, you will understand my delight at this clever name).
“We’ve seen a lot foundries in our region shutter their doors in recent years as manufacturing moves overseas,” said Aristo Cast CEO Jack Ziemba. “We see adopting new techniques like additive manufacturing, even when blended with our expertise in casting, as a way forward—not just for our company but for lots of other foundries in the Midwest.”
Aristo Cast realized that the weight of the airplane seat frame could be reduced even more if it was cast in magnesium, which is 35% lighter than the typical aluminum.
“We leapt at the opportunity to work with Andreas and Autodesk,” said Aristo Cast Vice President Paul Leonard. “It’s an exciting project and allowed us to pioneer some new techniques for magnesium casting. It also gave us a chance to learn more about advanced design and optimization techniques. That’s still quite new in our industry.”
Harris re-ran the part simulations in Netfabb for magnesium, to confirm its properties, and Bastian sent the updated 3D model to Aristo Cast. It was 3D printed in plastic resin first, and then coated in ceramic to make a negative mold; the plastic was later heated and vaporized off after the ceramic shell had hardened. Using the mold, the foundry casted small quantities of the parts, but was able to prove that the process could actually be used to scale up to 160 seats every two days.
Bastian and Pier 9 resident Rhet McNeal determined that each individual seat frame, weighing in at 766 grams, is 56% lighter than the aluminum seats currently in use: the magnesium accounts for 24% of this weight reduction, while the design optimization is responsible for the other 30%. So if Airbus, for example, replaced the 615 seats on 100 A380 jets, which have a typical 20-year lifespan, with Bastian’s lightweight frames, the airline could save over $205,000 (this is based on 2015 average jet fuel costs). Going back to eco-friendly matters, this translates into a reduction of 126,000 tons of carbon emissions.
Autodesk and Aristo Cast were recently honored by the American Foundry Society with its Casting of the Year award for the lightweight seat frame, which Bastian is quick to note is still just a research project, but one with “clear commercial applicability.”
Bastian said, “The purpose of this project was never to sell seat frames. The intent is to show the power of combining Autodesk’s advanced technologies in generative design and additive manufacturing with more a much more widely-used fabrication process: casting. Yes, there are great applications for aerospace, but this combination can also be used in automotive, medical devices, industrial equipment, and many other fields.”
Discuss in the Airplane Seat forum at 3DPB.com.[Source/Images: Autodesk]