Citizen L12-VII leverages more value out of small bar turn-milling

The 12 mm bar size capacity Citizen L12-V11 CNC sliding head turn-milling machines can produce both long or very short overall dimensioned components more effectively as the guidebush mechanism can be reset, fitted or removed. In addition, the machine also features the regenerative power capability when decelerating within the cycle that was first developed and included on the top-of-the-range Citizen M32. The L12 machine, featuring a high speed 15,000 rpm spindle and 10,000 rpm back spindle, has the latest Citizen Cincom 7-axis control and a 27-tool capacity. The driven tool positions also have the benefit of a maximum speed of 10,000 rpm to accommodate small tool diameters. The small capacity machine also boasts 35 m/min rapid traverse rates. Six turning tools and four driven tools can be mounted on the gang toolpost and four each to support machining at both the front and back spindle. A further four positions for driven or static tools are available in the back toolpost. Meanwhile, an optional three-spindle driven unit can be mounted on the going toolpost. Each spindle is double-ended and with an adjustable angle of between 0º and 30º from the centre line. The ability to switch from machining parts up to 135 mm long using the full support of the normal guidebush assembly in the main spindle – and with its removal, to effectively produce very short parts up to 30 mm in overall length – provides a further opportunity to maximise productivity through optimising the number of components produced from the length of bar in the machine. Without the guidebush a short bar end remnant only is required which is particularly valuable where expensive materials such as nickel silver, titanium and alloy steels are involved. Spindle power is 3.7 kW and 0.75 kW on the front and back spindles respectively, with driven tool positions having a 0.75 kW drive. The back-driven tools are powered by a 0.5 kW, 9,000 rpm motor. Citizen eco-control software can be used to monitor and display power usage, machine uptime and production cycle data. Peak level power display, for example, enables program change to maintain limits applied by the supplier's electricity band charges. A bar graph also displays information on power consumption over the working day and when the machine is idle, automatic power-off can be applied. A monitoring screen will display details of production/spindle utilisation from the automatic collation of data when the machine is in production, being set, or standing idle. The Citizen L12 VII occupies just 1,670 by 820 mm of floor space. The standard specification includes a large capacity swarf conveyor and 10-litre coolant tank. A workpiece conveyor can feed a finished part to the collection box for easy removal. Optional special control functions, using high speed arithmetic processing, such as milling interpolation, variable lead threading, canned cycle drilling, high speed rigid tapping, helical interpolation, hobbing and polygon functions, are available. Tool life management can also be specified.