Choice cuts

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Although machine tool technology is continuously evolving, modular designs that can be easily reconfigured make for economic efficiency and productivity. Martin Oakham reports.

The demand for increased productivity and quality by equipment manufacturers and their suppliers is forcing machine tool builders to constantly raise their game.

In the UK, for example, key sectors such as automotive and aerospace are relying on production technology to fight back against low-cost competitors. Companies in these sectors need versatile systems that can be configured to their needs, and the machine tool sector is responding.

Two world-renowned machine tool builders,

Heller Machine

tools and

Mori Seiki

, have a strong presence here and will be exhibiting some of their latest developments at next month's MACH 2008 at the NEC.

Heller plans to launch a range of horizontal machining centres (HMC). Described as a newly-developed machine concept, the H series assures availability for production, higher cutting performance, increased reliability and easy maintenance to provide economic efficiency and productivity — whatever the exact machining requirement.

The series — in red instead of the company's familiar 'Heller blue' — features many novelties, developed in close co-operation with customers and is a development of the proven Heller MCi and MCH technology. It will be manufactured at the company's Redditch facility in the West Midlands.

The H series operates at realistic speeds, rather than extreme rapid acceleration rates, therefore extending tool life, and saving energy and operational costs. Gaining a few tenths of a second is not what makes the difference. The crucial factors are productivity in the form of piece-part costs and availability for production.

Four models are available, the H 1000 2000, 3000 and 4000. The H 1000 and H 3000 offer a cost-competitive entry into the world of horizontal machining centres. Both are designed for a wide range of parts and materials in the medium volume range. The only difference is in size.

While the smaller H 1000 offers traverse paths of 630mm in all three axes, and the larger H 3000 provides up to 800mm in the X and Z-axis, the H 2000 and H 4000 are ideal for users requiring powerful machines for series production of varying volumes. These models are equipped with more powerful drives and a travel path of 630 or 800mm in all three axes. However, due to the modular structure of the variants and options available for both these models, customers can configure their own tailor-made machining centre using off-the-shelf components.

Apart from individual machine configuration, two optional packages are available. The 'Speed Pack', which is tailored to customers operating in non-ferrous machining, where fast and high accuracy work is required, and the 'Power Pack' catering for heavy cutting of cast iron and steel.

The H series is also flexible in terms of tool management. The standard tool magazine can be extended at any time, and can accommodate extra large or long tools.

'We are proud that Heller's UK manufacturing plant has been selected to manufacture these machines,' said managing director Geoff Lloyd. 'The H series horizontal machining centres are the machines which the market has been waiting for — small footprint, extremely versatile, easily tailored.'

The high level of standardisation also provides an excellent price- performance ratio while maintaining a high degree of flexibility.

Mori Seiki's focus for MACH 2008 is 'Pure Technology.' Its stand will feature eight machine tools including the new NMV5000 DCG 5-axis machining centre; the NZ2000 T2Y2 multi-axis turning centre with two spindles, two turrets and two Y axes; the NT4250/1500 SZ mill-turn centre; two NL series lathes; the NH5000 twin pallet horizontal machining centre; a DuraTurn 2550; and a DuraVertical 5100. The Dura series is claimed by the company to offer reliable machining accuracy at a reasonable price.

With the introduction of the 'NH5000 DCG' high-precision horizontal machining centre, all the models in Mori Seiki's best-selling NH series are now equipped with the company's unique Driven at the Centre of Gravity (DCG) technology, which is designed to minimise tool tip vibration and maximise speed.

As well as these, the company is offering the compact NX series. This features vertical and horizontal machining centres, and vertical turning centres boasting a machine width of 26.8in (680mm) the narrowest in this class.

All of the machines in the series are the same width, which makes it easy to switch them around within the production line to best match volume and design.

This development concept is claimed to be a first in the industry, and meets the demands of automotive production lines and the need for strict cycle times.

The NX2000 series, for example is designed to work with 3.9in x 3.9in (100mm x 100mm) workpieces, while the NXH3000 DCG, has a maximum swing diameter of 15.7 x 15.7 (400mm x 400mm). This machine is suitable for small to medium-sized mass production automotive parts made of aluminium, cast iron (FC, FCD) or steel, with a monthly line production target of 20,000-100,000 pieces and a required cycle time of 15-90 seconds.

Two features of the NX series, which is based on the principle of flexible line system construction, are the uniform machine width for all machines in each series (2000 and 3000) and the uniform table height throughout the series. The machine structure uses 'box-in-box' construction, offering high-speed, high-precision machining.

And although machine tool technology for the automotive industry is continuously evolving, it is clear that modular designs that can be easily reconfigured are here for the foreseeable future.