Page 28 - 3D Metal Printing Summer 2016

3D FEATURE
Add and Subtract
Add and Subtract
All in One
All in One
Where the worlds of additive and subtractive manufacturing meet, there’s a whole lot going on. New machines offer the advantages of both processes, and bring a new set of capabilities. BY LOUIS A. KREN, SENIOR EDITOR
Leaving out perhaps pottery-mak- ing, manufacturing traditionally has been a subtractive, or at most a shape-shifting endeavor. A chunk of work material was chiseled, cut, ham- mered or pounded into its final part form, with remnants of said material littering the workspace.
The advent of stereolithography in the mid-1980s heralded the modern era of additive manufacturing (AM), where resin was added layer by layer to slowly but surely achieve a part shape. AM existed primarily in this form until the last 15 years or so, when current 3D- printing technology was born. Through 3D printing’s formative years, additive and subtractive manufacturing (SM) progressed in parallel. Both technologies
brought advantages and disadvantages. CNC machining produced precision fin- ished parts, but reached limits in part design and often left precious part mate- rial on the shop floor as waste.
3D printing on the other hand, could produce parts designed for part purpose without the limits inherent in a particular manufacturing process, but part finish was lacking. Now the lines have crossed, and within the past five years, R&D by institutions and equipment builders, many times in the form of consortiums, has yielded production-capable machines that both add and subtract material to economically produce finished goods, prototypes, one-offs and limited-run parts.
CNC machining equipment now
26 | 3D METAL PRINTING • SUMMER 2016
3DMPmag.com