CNC sliding-head lathes fitted with one or more high speed spindles, capable of milling and drilling at up to 100,000 rpm, can extend the range of applications that are possible, and Star Micronics GB has demonstrated as much.

Star collaborated with electrospindle specialist Emmaco to install a lathe fitted with an 80,000 rpm IBAG spindle at a subcontractor in the North of England. The company needed to drill a 0.5 mm cross hole in a brass component, but the lathe’s 8,000 rpm driven tool speed was insufficient to achieve the ideal surface speed for efficient machining.

By fitting an electrospindle capable of 10 times the rpm, cutting speed was increased to around 40,000 rpm (63 m/min), resulting in better surface finish, higher productivity and reduced tool wear.

Ian Baker, managing director of Emmaco UK cites another application, this time in the medical sector. The cycle time for machining bone screws on a CNC sliding-head lathe was reduced from 7 minutes to 45 seconds by retrofitting an IBAG spindle. A further advantage was the elimination of burrs that were previously created by milling at sub-optimal speeds.

Mr Baker says that there is considerable interest at the moment from medical companies in high-speed units, especially for milling stainless steel using typically 2 mm diameter cutters. Not only are the best machining parameters attainable, but also the IBAG drive is particularly smooth, resulting in very fine component surfaces approaching a mirror finish in some instances. One US manufacturer has installed no less than 17 such spindles on one Star lathe.

There are over 60 high-speed spindles in the IBAG range suitable for fitting to CNC sliding-head lathes, including some designed specifically for mounting on the rear toolpost on Star machines. Fixed-angle and adjustable-angle units extend the machining possibilities.

http://www.machinery.co.uk/machinery-news/star-cnc-sliding-head-lathes/39554/