3D: Adding to additive’s capabilities
3D printing has gone mainstream. You can buy personal 3D printers at the end caps at Wal-Mart and Home Depot. In the two years since Plant Engineering reported on the coming proliferation of 3D printing—or additive manufacturing, as it is more properly called—the technology is becoming more visible to a wider audience.
We’re not quite at a 3D printer on every engineer’s desk. Yet. But Lynn Gambill and her team are working on it.
“We are buying various desktop or tabletop versions to bring to the designers here,” said Gambill, the chief engineer for manufacturing engineering and global services at aerospace manufacturer Pratt & Whitney. “They are in a lot of places. The cost of printers has gone down, making them available to so many different people. It’s a great visual aid in designing parts.”
Aerospace in general and Pratt & Whitney in particular have been on the cutting edge of additive manufacturing. The technology accelerated the transition from CAD drawings to manufacturing parts and gives designers a faster, cheaper way to puts new parts into production.
Gambill said the development of 3D CAD drawings already was a huge step forward. Additive manufacturing is one more giant leap. “Now a designer can create a 3D file and make a prototype part in short period of time,” she said. “You can do simple fit checks, and when you’re ready to interface with tooling, you also can make your tool.
“Parts can be made quickly, but they also can be made in a way that is very cost-effective for us,” said Gambill. “With additive, you can make parts and combine multiple details into the design. It’s certainly a benefit in terms of costs.”
On the leading edge
Local Motors is a collaborative auto design shop on the cutting edge of the 3D revolution. The company, with operations in Phoenix, Las Vegas, and Knoxville, Tenn., brought its 3D expertise to the 2014 IMTS Show in Chicago to print an entire car from front to back during the six days of the show. On the final day of the show, Local Motors CEO Jay Rogers and Association for Manufacturing Technology CEO Doug Woods drove the finished car out of McCormick Place.
The work leading up to that event highlights the leaps additive manufacturing is making. “There are a lot of kinks that have to be figured out,” said Justin Fishkin, chief strategy officer for Local Motors. “We didn’t even know we wanted to 3D print a car at the show. When we first started to print a large-scale unibody for the car, it took 180 hours. When we got to Chicago, it was down to 44 hours. That’s a huge efficiency.”
Additive manufacturing is one part of the way Local Motors is looking to expand its business as a custom car manufacturer. “We are on sort of the leading edge of the maturity of 3D. It’s at the beginning, but it has a long way to do.
We’re just scratching the surface. The traditional manufacturing capabilities always will have their place. They always will need each other. Things always will need to be welded. We’re just widening the tool set.”
While this is a time of great change in manufacturing, that change is happening in steps. Just as 3D printing takes place layer by layer, so is the growth of the industry. For Local Motors, that means continuing to prove out the capabilities.
“Right now, our business is about economies of scope as opposed to economies of scale,” Fishkin said.
That’s the same strategy they’re using at Pratt & Whitney. The company is moving additive manufacturing from the prototype stage to creating finished parts for its engines. On the journey to this next phase, the company has changed not only its manufacturing process, but also the parts themselves.
“We’ve been spending a lot of time training on design for additive manufacturing so we can try to learn what additive can and can’t do,” Gambill said. “It’s allowing designers to think about production without any of the prior manufacturing restrictions. You can make thin walls without having to worry about shape complexity. It gives designers a chance to imagine what the part might look like instead of what it historically has looked like. What you’ll start to see more and more—and not just in aerospace—is that the shapes of parts could look very different.”
The use of additive manufacturing at Pratt & Whitney extends beyond the part design to the material properties of the part itself. By combining various metal powders and new designs, the design team can fundamentally change the size, shape, and weight of engine parts. That can reduce cost, improve performance, and create lighter, stronger parts that will reduce fuel consumption.
“We’re now launching design teams for additive,” Gambill said. “When you design for additive manufacturing, you have the opportunity to take weight out of the part. It can drive the weight down rather substantially. If the engine weighs less, it uses less fuel. It all factors into the total cost of ownership.”
At Local Motors, the 3D printer has become integral to the design process. “One of the critical bottlenecks is that for a while, it’s been designers and engineers working on the same CAD model. Now they can communicate directly to the machine,” Fishkin said. “ It’s almost in real time, and we all can be working on the same model. If we don’t like way something performs, we print and try again. We don’t have to retool.”
That system allows not just for ongoing tweaking of part design, but also to test several variations of plastics, alloys, and metals in different combinations in the same part design with just one pass of the 3D printer. The parts may all look the same, but their physical makeup can be different.
Throughout the development of additive manufacturing, the technology has been seen as complementary to the traditional machine tool and CNC industry, and Gambill doesn’t see that changing. In fact, she said additive actually enhances the tooling process. “It’s not just about the parts themselves. There’s the tooling aspect, and they go hand-in-hand,” she said. “It starts really with powders, the controls, everything working to produce a part in semi-finished shape. Then it goes to downstream processing. In an operational environment, the goal is to have everything co-located and to create an operational value stream that is very effective.”
If the technology behind additive manufacturing is just now reaching store shelves, the strategic use of additive to advance manufacturing goals continues. “It’s not just a conversation about buying a piece of equipment,” Gambill said. “It’s about understanding what you’re able to achieve with material properties, and to achieve the design properties you need for a gas turbine engine.”
The collaborative nature of what digital manufacturing can do is important to Local Motors. The company is working with educational and government entities top help stay on the leading edge of research and technology around additive manufacturing. Fishkin sees a network of 100 microfactories all over the world, capable of producing 3D cars ready for the road, all printed off the same CAD drawing but deliverable anywhere there is a printer.
He also knows that network, and that world, is still some time away. It is coming, but layer by layer. “It’s going to be a long time before we’re printing critical parts for a car at home,” he said. “You’ll see people using it for fun stuff at home, and eventually we’ll be able to do more serious things.”
– Bob Vavra, content manager, CFE Media, firstname.lastname@example.org