Sliding Head Turning at Mach 2008

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In the first two days of MACH 2008, orders totalling £500,000 for sliding-headstock CNC lathes were taken by Star Micronics GB and by the end of the show, the figure was in excess of £1 million.  Managing director, Bob Hunt, commented that it made the company’s investment in the show wholly justifiable.

In addition, he said that the high quality of some of the enquiries taken on the stand makes him very optimistic that the final tally of orders as a result of Star’s participation at MACH will increase substantially.

Four of the companies that placed orders were completely new to the technology and another was ordering its second Star lathe in less than a year.  The conclusion that Mr Hunt comes to is that, despite decades of unremitting penetration of the turning market by sliding-head lathes, there are still a lot of manufacturers and subcontractors out there that can profit from adopting this style of multi-axis mill-turning for parts up to 32 mm diameter.

Such companies broadly fall into two categories – cam auto users looking for greater accuracy and one-hit machining to reduce labour costs and fixed-head CNC lathe users that have begun to realise that sliding-head cycles can be much faster, even on short parts.

The Star first order at MACH, for an SR-20RIII, was placed on the first day within hours of the show opening by Adam Marshall of Microplus Engineering, Stourbridge, specialists in centreless bar grinding and CNC turning.  Adam and his father, Alan, managing director, have been offering their customers turning in addition to grinding services for the past five years using fixed-head lathes up to 42 mm diameter capacity.

They now intend to extend their service into high-accuracy CNC mill-turning of shaft-type, mild steel and stainless steel components and decided that Star was the way to go.  The company is in the middle of an expansion phase that will see a move into a new unit this summer and a doubling of its grinding capacity from three to six metres.

On the same day, Gerald Gosnay, managing director of Hydraulic System Products (HSP), bought an SR-32JN.  The 32 mm diameter capacity model will be the first sliding-head lathe to be installed at the Wakefield company.  Launched at the show, the machine is unique in the Star lathe range in that does not have a guide bush, which HSP does not need as a large majority of its parts are 50 mm in length or shorter.  As the headstock is able to grip the bar very close to the point of machining, only a short remnant is left, resulting in big material savings.

Commented Mr Gosnay, “All components that go into our hydraulic products need a second operation.  Until now we have been achieving one-hit production on fixed-head, twin-spindle lathes with a single turret.  

Cutting trials on the Star showed a 50 per cent reduction in machining time through the ability to machine the front and back of components simultaneously.”

Pontefract-based Philidas produces automotive fasteners in anything from small batches to millions-off.  Fourteen labour-intensive, cam-type, multi-spindle automatics, some over 50 years old, run eight hours a day at the company’s works.  However, components are becoming more complex, sometimes requiring five or six separate operations, and competition from the Far East is increasing.

This was the background to Steve Webley, CNC team leader, ordering a Star SV-32.  He said it would do the work of six machines, one single-spindle fixed-head lathe and five multi’s.  He is delighted that there will be an eight-fold space saving on the shop floor, labour costs will be reduced by largely unattended 24/5 running of the Star, and cycles on the sliding-head lathe will be on average twice as fast as on the firm’s three fixed-head CNC lathes.

Another subcontractor heavily involved in supplying the automotive sector is Auto Turned Products (ATP), Northampton, whose technical director, John Dent, placed an order for a second Star SR-32J in under 12 months.  

A user of 16 cam multi’s and 40 turret auto’s in addition to five high-specification fixed-head CNC lathes, ATP found that second operations after conventional turning had risen to such an extent that single set-up machining on a Star mill-turn centre was needed to maintain competitiveness.

Said Mr Dent, “What surprised me was just how easy to program, reliable and repeatable the first Star is.  We come in every morning to a bin full of close-tolerance, complex parts after an unmanned ghost shift overnight.

“One component in particular has resulted in big labour cost savings and improved quality, namely the locking feature on wheel nuts we supply to Land Rover and Jaguar, including for the new Jaguar XF.  Previously produced in two set-ups on a fixed-head CNC lathe and a machining centre, the component is now produced in one cycle on an SR-32J to very high accuracy, despite the toughness of the material.”

Alan Riley from Newtech High Speed Turning, Widnes, ordered a Star SB-16C at MACH to expanding the subcontractor’s CNC turning capacity, which until now comprised three fixed-head lathes for producing parts up to 180 mm diameter.  Although the company is new to sliding-head technology, Mr Riley has had previous experience of using Star machines.

Newtech had identified opportunities to expand existing contracts and win new business in additional markets by focusing on smaller diameter, shaft-type components of greater complexity.  The SB-16C will initially be used for production of electrical connectors and catering industry components in batches of from 200- to 100,000-off.  Installation of the sliding-head machine will also enable the company to break into the medical industry, in particular the manufacture of orthopaedic components.

Concluded Mr Hunt, “We are particularly pleased to welcome these five new companies into the Star fold.  Many of the subcontractors that became customers back in the 1990s now use Star machines counted well into double digits – firms like Techno Group and Qualiturn in England and Tercet and Bonspiel in Scotland.

“It is obvious what the potential benefits are to Star GB of the new customers that ordered machines from us at MACH.  We play our part too by guaranteeing that they are successful.  We do this by providing a personal service, from industry-leading applications engineering before the order is placed right through to comprehensive training and after sales service.”