Latest linear motor technology is being used to remove any likelihood of deflection and backlash and to optimise slideway structure of the most recent CNC sliding head turn/mill centre.
The latest linear motor technology is being utilised by Citizen to remove any likelihood of deflection and backlash from the power transmission system and to optimise the structure of the slideway on the latest R07 Type VI CNC sliding head turn/mill centre. With this design, which is exhibited under power on the NC Engineering Stand 5262 at MACH 2006, Citizen has been able to create a very compact machine and capitalise on combining super precision with high speed 'one-hit' machining cycles on components up to 7mm diameter by 40mm long. The RO Series, which features the RO4 and RO7, has proven to be an outstanding success in Switzerland and particularly in the watch making sector due to its compact dimensions that enable an easy substitution to traditional cam auto machines.

Productivity being found to be higher with the added bonus of consistency of production and the flexibility of CNC to enable development of the turn/mill process to further reduce cycle times.

With six-axes, a main and subspindle and up to 13 tools available, of which three are driven, two tools can be brought into action simultaneously, which means the new Citizen R07 is reckoned to be significantly faster than a traditional cam auto when machining small parts in single cycles.

It has the advantage of a very compact footprint of 560mm by 1265mm when installed on the shopfloor, has no hydraulics or pneumatics and is totally electric and electronic in operation.

The 16,000 rev/min, 1.1kW built-in main spindle has precision ceramic bearings for optimised machining of small diameter parts and a 0.5kW secondary spindle with an 8,000 rev/min capability.

It has two independent toolposts able to hold 13 tools, of which three are driven by 0.2kW, 8,000 rev/min spindles.

An important development with the R07, that significantly increases machine utilisation, is the ability to open and close the collet at normal machining revolutions without adding to the cycle time by slowing the spindle.

Accuracy is high with increments of 0.0001mm in each axis and repeatability of one micron is possible.

By combining linear drive technology to both tool posts, high productivity is guaranteed with rapid acceleration to maximum traverse rates of 20m/min.

The maximum machining length is 40mm and with the two slide arrangement, five turning tools can be mounted on the gang tool post with two cross-driven tool positions.

In addition, three end working tools can be applied to each of the main and sub spindles to optimised orders of positioning accuracy through the use of glass scale encoders.

The main spindle has 1 deg indexing and both spindles have rotational synchronisation for part transfer.

There are a number of canned cycles for polygon turning, thread cutting, drilling and rigid tapping and constant surface speed is standard to minimise cycle time and maximise surface finish.