Technology Goes Mainstream
As the advantages of additive manufacturing become more realizable with new technologies, numerous companies are turning to this custom approach to build not only prototypes, but also to produce parts by the hundreds.
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| Numerous companies are turning to additive manufacturing to build not only prototypes but also parts by the hundred. |
"We saw the technology as a benefit to us, and we've been using it for three or four years," says Tim Kamleiter, aerospace manager at C&A Tool, a privately held contract manufacturer of parts for the medical, automotive and aerospace industries based in Chiarabusco, Ind. "Most of what we do is production of parts for final assembly, such as diesel-fuel injectors." With about 535 employees, C&A Tool uses additive manufacturing to turn out parts in quantities ranging from one to a few hundred.
In the additive manufacturing process, parts are created from a 3-D computer-aided design model by building up successive layers of metal or plastic in the desired form and shape. This method differs from most traditional manufacturing methods, in which parts are formed by subtraction -- shaping, boring, cutting, trimming, sanding and otherwise removing material until the finished item has been reduced to the desired shape and size.
Although traditional manufacturing also has included fabrication methods that are basically "additive" -- joining metal plates, forgings and rolled steel via rivets, screws or welding -- these methods aren't driven by the information-technology component of a CAD model.
Currently, the chief limitations for the additive process are the type of materials and the part size. Most parts are made with titanium, specialized steels or other metals, or various plastics. The size limitation is dictated by the build platform. C&A Tool, for instance, which uses an EOS machine, works with a 10-inch by 10-inch by 8-inch build platform. "That's pretty consistent with what we make," Kamleiter says.
The chief advantages of additive manufacturing are the speed of manufacture versus traditional machining, and the flexibility of design. Most parts can be produced in a matter of hours, although Kamleiter says some parts can take up to 400 or 500 hours. Parts that contain blind holes or inside passages that are impossible to produce via other methods can be built through the additive or layering process. "Using laser-sintering technology, we can produce something you can't make in the traditional ways," he points out.
The process may sound labor-intensive, but it's not. "Thirty hours is a typical build time, but the machine runs lights out, although we check on it from time to time," Kamleiter says.
The additive process also is attractive to markets such as the medical industry that need products right away. "Speed is important for the medical industry," Kamleiter says. "We can make a part in hours without the delays of the machining process."
