Production Machining - Your access to the precision machining industrial buyer.
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By Russ Willcutt I n manufacturing, it's a simple fact that if you're not cutting chips, you're not making money. So compa- nies that are not running a third shift are losing a full eight hours of daily production, and even more on the weekends. Recovering that lost productivity was a primary impetus behind the development of lights- out machining in the late 1980s and early 1990s. In those days, however, the process presented quite a few challenges having to do with sustained quality and repeatability, and especially undetected tool failure during the unmanned hours that led to some nasty surprises when the first shift began. Before monitoring systems were developed that automatically shut down a machine should something go wrong, it would simply keep on churning out parts, resulting in dismayingly high scrap rates. Technological advances in recent years have mostly eliminated these problems, revealing unexpected benefits as the process has become more reliable and robust. In addition to systems that automatically alarm out and shut down the machine at the first sign of a problem, which reduces scrap rates, quality has improved to the point that operators can rest assured that the last part produced will be an exact duplicate of the first. Equipment can also be programmed to switch from machining one part to another any number of times overnight, as long as the parts are within the same family and are cut from the same size barstock. Slim Haney Machining has enjoyed a front-row seat to these ongoing developments, having delved into lights- out machining on its CNC Swiss-type lathe in 2008. e success of that endeavor led to outfitting a standard lathe for unmanned machining, and a third is currently going through trial runs, producing prototypes to dial in everything before going into production in the coming months. A review of the company's experience—the challenges it faced early on, how they were overcome, the benefits it is now accruing, and the flexibility it has brought to the opera- tion in terms of machine availability and allocation—provides a useful road map for any machine shop consid- ering doing lights-out manufacturing. Filling Bins While the Building is Empty Over the past decade, technology has advanced to the point that lights-out machining is more seamless than ever before, with built-in safety systems and even the ability to switch from one part to another in the middle of the night. :: Brass is the material of choice for lights- out machining at Slim Haney because of ease of cutting and low tool wear, lessening the chances of tool failure during the night. LIGHTS-OUT MANUFACTURING 32 PRODUCTION MACHINING :: NOVEMBER 2016