I remember seeing my first 3D printed “part” in early 2000, back when it was called rapid prototyping. It was a replica of a small part used in a car that a major OEM was designing. The part was made of plastic, with a rough surface finish, used on a packaging buck to see if the part fit physically and aesthetically. At the time, I asked if the process could make production parts. I was told then—and basically still today—it was many years away. Oh sure, GE is reportedly 3D printing some intricate metal parts used in its LEAP engines, and I am sure there are other such low-volume, small-part applications now that 3D printing with metal has come of age. But a production part for automotive at 60 jobs per hour? A whole car body in production, like we saw at the IMTS show in 2014? These are the obvious questions and the answers seem dim.
Problem is, these may be the wrong questions to ask.
I was alerted to this by a talk given by Dr. Lonnie Love, a corporate fellow at the Oak Ridge National Laboratory, speaking at the Center for Automotive Research’s annual industry Management Briefing Seminars in August 2017. ORNL was one of the partners, along with Cincinnati Inc., that brought that print-at-the-show Local Motors car at IMTS in 2014.
The group used technology they called Big Area Additive Manufacturing, or BAAM. While impressive in its scope, the surface finish was poor, Love acknowledged, noting that it looking “like melted crayons.”
The next iteration was to print a car body with BAAM, then finish and coat it afterwards to create a true class A surface, which was done with a more recent Cobra project. In this project, using BAAM, Love’s team built a replica of a Cobra sports car complete with powertrain in six weeks. However, musing on the question of the reality of cars printed on demand, he is skeptical that it will be practical any time soon.
Again, it’s probably the wrong question. What does get him excited is using additive manufacturing (AM), for tooling to make car parts. If you acknowledge that AM has its strength in low-volume, complex parts, well, that describes the tooling industry. “AM enables manufacturing of new geometric shapes [of tools] that are not possible with conventional methods,” he said in his talk. For example, cooling channels are especially important in molds and tools. Precise cooling of tools and components means reduced cycle time. AM is ideal for creating intricate, hidden channels and other complex features. And with AM, they can be cheaper to make.
Experimenting with the technique as part of its Cobra project, Love’s team found that it could produce a low-temperature mold suitable for producing a class A surface, like the hood on the Cobra, for a few thousand dollars in two days. “Typically, these molds cost hundreds of thousands of dollars and take months to make,” he said. He also showed a 3D printed trim and drill tool that will be used in building Boeing 777x airplanes. Other results included high temperature and high-pressure tools in aerospace autoclaving, and a compression forming tool for Ford Motor Co. designed to operate at 180 degrees C and 2000 psi.
The whole “right-or-wrong-question conundrum” was brought home to me in a different setting. Visiting a metrology equipment reseller, I discussed with a quality inspection professional how difficult it might be to verify intricate internal channels of parts made with AM—especially with the vision-based metrology system that I was there investigating. “Maybe,” he said, “but where I’ve seen 3D printing used is in creating intricate fixturing to present the parts in the right orientation to the camera.”
AM was indispensable to at least one vision metrology professional—who was asking the right question.