The Citizen M20 is able to carry up to 80 tools on its 10, all-driven position turret, five turning tools and three rotary tools on a gang tool post and a further three rotary tools on a third slide.

The Citizen M20 is able to carry up to 80 tools on its 10, all-driven position turret, five turning tools and three rotary tools on a gang tool post and a further three rotary tools on its third tooling slide. This high level of tool carrying capability, to support the main 3.7 kW and 1.5 kW back spindle, not only makes one of the most flexible of tool setting arrangements, it allows 'permanent' tool settings to be held on the machine to give ultra-fast changeover between different jobs. Now available from NC Engineering of Watford, the Citizen M20's all-electric turret design has a 0.3 secs chip-to-chip time which is a key element in its high productivity capability.

Each of the 10 turret stations can be half indexed under CNC control which doubles the number of basic 20 tool positions and, through special tool holders, up to four tools can be held at each position to create a total turret capacity of 80 tools.

In addition, special tooling such as cross-angle rotary head drives or thread whirling tools for internal threading can be utilised in conjunction with a Y-axis turret movement providing an off-centre machining and interpolation capability.

Both main and back spindles are fitted with C-axes.

With this level of flexibility, the M20 becomes almost a hybrid lathe/machining centre for small turned parts up to 20 mm diameter and 600 mm long.

And, with the addition of certain options, long periods of unmanned running can be achieved.

These include an integrated parts handling device which retrieves the finished component from the back spindle for storage in a parts stocker or carried outside of the machine, to prevent damage.

An automatic component gauging device can also be installed on a turret station to measure outside and inside diameters and tool wear detection can be included to measure and compensate the CNC control automatic tool wear adjustment.

The machine base is compact, extremely rigid and built around a 45o slant design for good swarf control and easy setting access.

The main spindle motor is fully integrated giving exceptional levels of noise control and a high precision surface machining capability.

Spindle speed is fully programmable between 200 and 8,100 revs/min.

The back spindle too is a built-in design with 150 to 7,200 revs/min and rapid traverse rates are 18 m/min.

The elimination of hydraulics and pneumatics, in favour of an all-intelligent servo-driven machine design, means maintenance and running costs are reduced while ultimate synchronisation of the, up to three tools simultaneous cutting capability, can be easily performed at the control.

Cycle times, compared against the previous generation of M20 and using the same program, should be about 20 per cent quicker.

This opens up a large sales opportunity for NC Engineering to upgrade existing users of one of the most popular citizen machines in the UK based on a higher productivity justification.