A20 sliding-head delivers high performance at low cost

The A20 CNC sliding-head auto is the first in Citizen's line-up of high performance turn/mill centres developed to support a lower capital outlay, provide greater levels of rigidity and combine many of the proven features of its higher specification machines. A first also is that it is available in left- and right-hand variants, enabling factory layouts to be optimised. Developed around a heavier duty casting, approaching double the weight of a typical 20 mm capacity machine, vibration absorption, higher metal removal rates and high levels of thermal displacement were prime design criteria for the new machine. The Citizen A20 is able to carry up to 17 tools, three of which are driven. It has a 3.7 kW, 8,000 rpm main spindle built to the same rigidity standards as the top-of-the-range Citizen M32 sliding head turn/mill centre to facilitate heavier duty cutting cycles. The 1.5 kW, 8,000 rpm back spindle shares common higher rigidity components with the main spindle, and both have in-built motors. Operating cycles have the benefits of features such as constant surface speed, speed fluctuation detection, continuous thread cutting and are capable of simultaneous rigid tapping. Citizen’s streamline control technology in conjunction with the Fanuc based Series 32i-Model A control, has been incorporated following its success in cutting idle times in a machining cycle. To aid machine program prove-out, Citizen’s popular on-machine program check function is included enabling manual forward and reverse cycle or part cycle operation. There are several tool layout options that can be specified as well as tool shank sizes and included as standard is the latest Sandvik Coromant QS quick-change tool system. This exclusive breakthrough development by the tooling company and Citizen in Japan, that enables tools to be accurately changed in 20 secs and inserts indexed out of the confines of the cutting zones, is a major contributor to improved machine utilisation. For longer components such as spools, valves and throttle spindles, up to 165 mm lengths can be machined in a single chucking stroke which can be extended to 300 mm with just a single re-chucking. A component separator, able to handle parts up to 80 mm in length is standard, with an option available to enable longer components to be manipulated.