Bushey-based Citizen Machinery UK Ltd has increased its capability in micro-part turn-milling technology and small-part turning with the launch of two versions of its new-generation modular-build R-series sliding-head lathes. (www.citizenmachinery.co.uk)

The latest type VI R01 and R04 machines have bar capacities of 1 and 4mm respectively, with common front- and back-spindle modules, and the ability to carry up to 17 tools.

Aimed at the watch-making, medical and miniature-component sectors, these machines require a floor area of just 1,465 x 535mm.

In order to achieve the precision required for micro-machining, spindle design is critical. The spindles on these latest machines are oil-cooled, and both the main spindle and the back spindle are more compact, being 25% shorter and proportionately lighter.

In addition, each spindle offers greater rates of acceleration and deceleration, while minimising the onset of vibration. High-speed ceramic bearings maximise stability, and each spindle on Type-VI machines is powered by a 0.75kW motor giving a maximum speed of 20,000rev/min.

Another new development is the twin gang-tool slides mounted vertically either side of the spindles, with the X-axis tool slide featuring linear-motor drive technology; this gives fast acceleration to a maximum speed of 30m/min, while adding to the machine’s precision by eliminating deflection and backlash.

To ensure that the machine remains compact, the Y axis is driven by a servomotor, but it still achieves the same 30m/min rapid-traverse rate. Of the 17 tools, there are seven for turning, eight for front drilling and two driven positions powered by 0.1kW 8,000rev/min motors.

To help with the machining of micro-components on the R01, a non-contact air-blow collection chute is available to collect workpieces up to 1mm in diameter x 5mm long (this device also separates chips from the components).

A front collection chute can be specified for workpieces up to 2mm in diameter and 20mm long.