NEW CITIZEN A20-VII ADDS FLEXIBILITY AND HIGHER PERFORMANCE SPECIFICATION

The latest Type VII version of Citizen’s most successful world launch of one of its CNC sliding head automatic lathes, the seven-axis up to 21 tool A20, incorporates a new X-2 axis on the back spindle and back tool post that further improves machining flexibility enabling simultaneous cutting with two tools on the front and reverse ends of a component. The machine also has the benefit of built-in 8,000 revs/min spindle and subspindles and improved rapid traverse rates from 18 m/min to 32 m/min. With four, 6,000 revs/min driven tools available as standard, one is also able to be interchanged to accept face, rotary or slitting style tools.

The original A20 was an immediate success with its heavier duty cast construction almost doubling the weight of a typical 20 mm capacity machine. Not only did this enable heavier cuts to be taken, it improved vibration absorption when milling and created very effective thermal displacement characteristics giving a more consistent production platform over extended periods and especially when running unmanned.

Also very important to users was the benchmarking of a high specification machine in a ready-to-run package requiring a lower capital outlay.

The Citizen A20-VII from NC Engineering of Watford continues the same value for money theme with higher flexibility for machining parts up to 165 mm long. This package price includes a 3 m Iemca bar feed unit, a workpiece conveyor, delivered and commissioned. Sandvik Coromant’s QS quickchange tool system, developed in conjunction with Citizen, is also a standard feature. This system enables utilisation of the machine to be improved with tools changed in just 40 secs.

The Citizen A20-VII is available in left and right hand main spindle formats giving higher flexibility for factory layout and the on-the-shopfloor installation deal from NC Engineering includes full training to enable the customer to maximise the return on the investment.

Both the main and subspindles are built-in avoiding the use of belt drives. The main spindle is powered by a 3.7 kW drive and the subspindle by a 1.5 kW unit with both spindles having maximum speeds of 8,000 revs/min and full C-axis. The modular toolholder configuration will hold up to five turning tools. There are also four front end tools and eight positions for back end machining that can be split into four tools on each side of the spindle.

There are four 6,000 revs/min driven tools powered by 0.75 kW motors positioned by a Fanuc-based Series 32i control that incorporates the Citizen developed ‘Streamline Control’ software technology. Not only does this high speed processing software very successfully reduce idle or non-cutting times and improve productivity through the use of overlapped sequences, it introduces new levels of programming and operational flexibility.