3D printing, married
to traditional metal
casting, could reshape


MAY, 2017


Additive Manufacturing


Metal casting

Autodesk has partnered with a Michigan foundry in a 3D printing proof-of-concept project that resulted in a new magnesium commercial airline seat frame so light it could save an airline more than $200 million in fuel costs.

Autodesk used its Netfabb 3D design software to produce a complex geometric model for a new aircraft passenger seat frame just as strong as a traditional seat, but vastly lighter.

The CAD program created a file used to 3D print in plastic the seat frame, which was then coated in ceramic material and heated to a high temperature to evaporate the inner plastic.

The remaining ceramic mold was then used by Aristo Cast, a Michigan foundry, to manufacture a magnesium seat frame that weighs 766 grams, 56% lighter than the conventional 1,672-gram aluminum seats in use today.

While laser sintering, another 3D printing method, offers the ability to create objects with dozens of metals, it is slow compared to metal casting, which can use thousands of metals or composite materials.

Additionally, 3D printing is limited to the relatively small size of a print beds – only a few feet in size — even in commercial machines. Traditional metal casting has nearly limitless production scalability.

With the resulting ceramic mold, Aristo Cast confirmed it could make up to 160 of the magnesium airplane seats every two days.

Autodesk and Aristo Cast claim that if an aircraft maker such as Airbus were to replace all 615 seats on its A380 jets with the new, lighter magnesium seat frames — across a fleet of 100 planes which typically have a 20-year lifespan — the move would save  $206 million, based on average jet fuel costs in 2015. Along with reducing fuel costs, the new seats could also mean 126,000 fewer tons of C02 emissions if used on a single model aircraft.

“While additive manufacturing holds great promise for the future of manufacturing, it’s still very new for many product developers. Casting, by contrast, has been around for millennia and is incredibly well understood,” Autodesk research scientist Andreas Bastian said in a statement. “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.”

For the past year, Bastian has been working at Autodesk’s 27,000-square-foot technology center in San Francisco to produce the lighter airline seat. Bastian used the algorithms in the Netfabb 3D design software to create an intricate latticework that resulted in a seat just as strong.

“We leapt at the opportunity to work with Andreas and Autodesk. It’s an exciting project and allowed us to pioneer some new techniques for magnesium casting,” Paul Leonard, Aristo Cast’s chief engineer, said in a statement. “It also gave us a chance to learn more about advanced design and optimization techniques. That’s still quite new in our industry.”

While a breakthrough for airline seat frames, what Autodesk and Aristo Cast is similar to what is being tested in other industries.

Ford Motor Co., for example, has been using a myriad of 3D printing technologies to manufacture working prototypes for car and truck parts.

The carmaker has five 3D prototyping centers, three in the U.S. and two in Europe. At its Dearborn Heights, Mich. facility, 14 different industrial 3D printers turn out 20,000 parts a year. A single print run on one machine can create anywhere from a few parts to hundreds.

One 3D printing method, called binder jet printing, lays down layer upon layer of sand. Each successive layer of sand is bound to the last with adhesives to create a mold for making metal prototype parts that used to take up to 10 weeks to create using conventional molds.

Typically, aluminum is used for airplane seats, but magnesium is 35% lighter. Autodesk’s 3D design optimization resulted in more than half of the weight reduction and the magnesium accounted for the rest, Autodesk claims.

For Aristo Cast, combining a newer technology like 3D printing with proven metal casting techniques could spur new growth in its industry.

“We’ve seen a lot foundries in our region shutter their doors in recent years as manufacturing moves overseas,” Aristo Cast’s CEO, Jack Ziemba, said in a statement. “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.”

Today, using binder jet printing, prototype molds can be used to produce hundreds of molds on a single machine in about a week.

Another method in use at Ford is laser-sintering, where several machines perform rapid prototyping of parts by melting hundreds to thousands of successive layers of fine silica together. What emerges from the printer is an amorphous block of powdered silica from which dozens of hardened parts are removed by hand and cleaned with a brush and vacuum.

What is also unique about Autodesk and Aristo Cast’s proof-of-concept project is they not only reduced an airline seat weight with a more sophisticated frame design, but they were able to cast in magnesium — no simple task.

Author: Lucas Mearian
Media: ComputerWorld