Production Machining

NOV 2018

Production Machining - Your access to the precision machining industrial buyer.

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productionmachining.com :: 31 SPECIL COVERGE :: Metal 3D printers, including this selective laser melting (SLM) machine from Realizer, can be used to produce parts that replace castings or eldments, as ell as make parts ith features that cannot be machined. Hoever, these systems are expensive and require special expertise (such as metallurgy) to operate. "Advanced rendering capabilities allow us to visualize work on a computer screen quite well these days, but there's nothing like holding it in your hand and putting the parts together to see if they t," he says. Replacing metal castings and weldments. Metal AM can be used instead of a number of di•erent processes for producing parts. For example, injector nozzles that in the past were made of several parts welded together can now be 3D printed as one part. Castings are also being replaced with metal additively manufactured parts. When these parts come out of the 3D printer, they require additional work. "We can't 3D print really highly accurate surfaces," Mr. Miller says. "We still have to machine those critical surfaces." Understanding additive manufacturing technology, as well as its strengths and weaknesses, will help shops perform these machining operations. Mr. Miller sees this as a key area of growth and a big opportunity for shops. For shops that do perform these operations, he adds that it is helpful for them to consider 3D printing as part of their upstream process. Producing parts that can't be machined. Possibly the biggest advantage of additive manufacturing is that it can be used to produce parts that cannot be machined. Aerospace parts and medical implants with complex internal features, for example, can be 3D printed in either metal or plastic. …ese parts must then be brought into tolerance using machining methods such as turning. Repairing parts. According to Mr. Miller, hybrid manufacturing systems are mostly used for repair. The additive manufacturing capabilities of these systems are used to add stock to damaged parts, which can then be turned in the same machine to be brought into tolerance. :: Polymer 3D printers can be used to quickly produce one-off parts as ell as parts that cannot be machined using traditional methods. (Photo courtesy of Stratasys) here to Start With so many di•erent types of technologies, systems, brands and materials, shops that want to begin incorpo- rating additive manufacturing into their operations might have a diˆcult time knowing where to start. Mr. Miller o•ers these suggestions: Outsource metal AM. Because of the cost and exper- tise required, Mr. Miller recommends that shops initially outsource metal 3D printing. "Let the experts be the experts," he says. …en, when the volume picks up, shops can re-evaluate whether it makes sense nancially to bring that process in house. Purchase an FDM 3D printer. According to Mr. Miller, polymer additive manufacturing systems can easily be brought in house and do not require a lot of special knowl- edge to operate. He says that of the di•erent polymer 3D printing technologies available, fused deposition modeling (FDM) systems are the easiest to get up and running. …ese systems use laments of plastic materials, which are extruded through a heated nozzle onto the print bed to form the workpiece in layers. …ese systems are also sometimes called fused lament fabrication (FFF) or material extrusion. When choosing an FDM 3D printer, Mr. Miller cautions shops to avoid using inexpensive desktop machines for professional work. "…e quality is just not there, and you'll spend more time ddling with it and trying to get it to work," he says. He recommends that shops spend between $10,000 and $50,000 on a good entry-level machine. As for where to start when searching for a 3D printer, he suggests that shops do some research online and talk with salespeople to get an idea of which system is the best t for their applications. Shops can also

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