Nottingham-based subcontractor Doughty Precision Engineering (Nottingham, UK) has doubled its number of Nakamura Tome 7-axis CNC mill-turning centres to four in an effort to minimise the number of separate machining operations. Supplied by Mills Manufacturing Technology, the machines are devoted to the production of electrical connector parts for the aerospace industry from stainless steel bar up to 65mm diameter. Called receptacles, the components are milled and drilled on the Nakamura Tome lathes for about 50% of the cycle time. The only subsequent operations needed are keyway machining on a CNC slotter and deburring using a boring bar on an older CNC lathe that no longer performs mainstream production duties. Simultaneous front- and reverse-end machining minimises the cycle time, which is set by the sequences needed to complete the front end. Then after part-off and synchronous pick-up by the right hand spindle, as much milling as possible is completed from the back as the turning operations are fairly limited. The benefit the Nakamura WT machines offer is that both turrets can work on either right or left spindle to ensure minimum total cycle times with maximum throughput.
