Production Machining

NOV 2018

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

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By Julia Hider 30 PRODUCTION MCHINING :: NOVEMBER 2018 SPECIL COVERGE dditive Manufacturing in the Turning Shop t rst thought, seeing how additive manufacturing ts into the shop of the typical Production Machining reader may be dicult. But as our readers begin expanding the capabilities of their shops, it is natural for them to consider additive manufacturing. Although this technology is still relatively new to the machine shop, it is promising and has been generating a lot of interest. To nd out how additive manufacturing could work with precision turning, we reached out to Eric Miller, co-owner and principal of Phoenix Analysis & Design Technologies Inc. (PADT), which provides a range of additive manufac- turing equipment, services and support. From our conversa- tion, it became clear that 3D printers will not be replacing lathes any time soon. Nevertheless, there are several reasons to understand and start exploring this technology. For starters, customers are likely thinking about it and talking about it. "‡ey want to make sure they're not missing something," Mr. Miller says. Even if additive manufacturing is not a good t for a customers' needs, shops need to be able to condently explain why. "Knowing when AM is and isn't a good t is a competitive advantage for a shop," he says. And even though they may not be numerous right now, there are circumstances in which additive manufacturing can complement turning. Mr. Miller says the need for these applications is growing and presents big opportunities for the precision turning industry. Another reason to look at additive manufacturing technology now is that it could soon advance to the point where it will be a better complement to precision turning. According to Mr. Miller, systems that will increase AM's productivity, as well as make it cheaper and easier to imple- ment, are currently in development. hat is dditive Manufacturing? According to Mr. Miller, a good rst step to exploring additive manufacturing is adopting the right mindset about the technology. "Don't treat AM as di‹erent," he says. "It's just another machine tool." Like every other machine tool, it requires materials, it needs to be programmed, and many of the parts that come out of a machine need post processing. "It's just a di‹erent way of making a part," he adds. ‡ere are two main types of materials used in additive manufacturing: polymer and metal. Each has di‹erent strengths, weaknesses and uses, especially when it comes to how they are used in combination with turning processes: Polymer. Polymer (or plastic) AM can produce parts that cannot be made by traditional machining processes, such as complex internal features in medical implants. It can also produce one-o‹ parts quickly. In addition, these systems tend to be easy to program and can be run without much training or special expertise. However, accuracy and surface nish can be a challenge, and the technology is only cost-e‹ective for producing small volumes of parts. Metal. Metal 3D printing can also produce parts with features that cannot be machined. Like polymer 3D printers, metal 3D printers struggle with accuracy and surface nish. In addition, they are expensive (capital equipment and infrastructure costs are currently between $300,000 and $1.2 million, according to Mr. Miller) and often require special expertise (such as metallurgy), which makes them dicult to implement. Shops also need to consider the material properties of 3D-printed metal parts. Metal 3D-printed parts may be able to replace castings, but the technology cannot replicate the material properties of forgings. Metal additive manufacturing can also be combined with traditional, subtractive machining methods. Hybrid manufac- turing systems are CNC machines (usually multitasking or milling machines) with metal deposition heads. ‡is design gives them the ability to both add and remove stock within the same machine. Ho to Use M According to Mr. Miller, there are several ways shops that focus primarily on turning could use or encounter additive manufacturing: Tooling and xturing. For polymer 3D printing, Mr. Miller says the number one use in the machining space is tooling. Although turning does not require the complicated tooling and xturing of milling, additive manufacturing can still prove useful. For example, a shop could 3D print a plastic sleeve to protect delicate parts from being damaged by the chuck as they are being turned. ‡e sleeve ts around the part, and both go into the chuck. Designs and prototypes. Polymer AM is also well- suited for design and prototyping. For shops that do a lot of up-front prototyping, buying a 3D printer and doing the work in house could be more cost e‹ective than outsourcing the work. Polymer 3D printing o‹ers a quick turnaround on prototypes, which can be used to determine form, t and possibly function. "You can make sure the parts are good before you go to machining and make 300 or 3,000 of them," Mr. Miller says. He adds that 3D printing can help speed the design process for design engineers.

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