b'SHOP TRANSFORMATIONCNC machines and CAM software enable advanced milling techniques.By Christopher Tate nology, our methods were crude.Ithe privilege of learn- Machiningcentersand had ing the machining craft attechniques have advanced my familys machine shop. Itat a fast pace since I started was a true mom and pop shopprogrammingandoperat-where we made anything thating CNC machines. A few sig-would pay the bills. As ordersnificant improvements have grewlargerandpartsbe- transformedthemachines came more complex, it wasinto what we use today, en-clear that our future would de- hancing shop and machinist pend on successfully integrat- efficiency.ing CNC equipment into our shop. In 1995, we purchasedNeed for Speedour first machining center: aOur first CNC machine was small one without any options. capable of only a 7,500-rpm Buying it launched our shopspindle speed. Although ma-to the next level. Five weekschineswereavailablewith after receiving the machine,higher-speed spindles, those we ordered another just likemachines were expensive and it. I programmed them withrarely found at small shops.a pencil, paper and a calcu- When we bought our origi-lator, typed codes into thenal machines, we would have controls and stored all pro- needed to use some type of grams in the machine toolancillary device, such as an controls. We used edge find- air spindle or a geared spin-ers and indicators to set partsdle speeder, to achieve higher and measured tool lengths byspindle speeds. In addition to touching parts with each tool.being costly, spindle speed-Compared with todays tech- ers were often unreliable and about the author Christopher Tate is engineering manager of advanced manufacturing engineering and machining at the Savannah, Georgia, facility of Mitsubishi Hitachi Power Systems Americas Inc., Lake Mary, Florida. Contact him at chris23tate@gmail.com.56APRIL 2020 Milling.indd 56 3/16/20 4:59 PM'