Product category:
General Machining Subcontracting Services
News Release from: Star Micronics GB | Subject: Sliding-head lathe
Edited by the Manufacturingtalk Editorial
Team on 24 April 2007
Sliding-head lathe ups mill-turning
productivity
Sliding-head mill-turning centres with high pressure coolant, supplied by Star Micronics, have boosted productivity by 30 per cent at DKW Engineering.
Four years ago, Portsmouth-based contract machinist, DKW Engineering, lost 40 per cent of its business to China, most of it simple turning and milling work Today, direct exports to that country account for 15 per cent of DKW's turnover and the lost business has been largely replaced by higher-added-value contracts for the production of more complex components
This article was originally published on Manufacturingtalk on 31 May 2001 at 8.00am (UK)
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Many subcontractors have found that the answer to competition from low-wage countries is to move away from manually operated machine tools to one-hit production on CNC lathes and machining centres.
This is exactly what DKW's managing director, Nick Iacobucci has done.
Since 1997 he has decommissioned 60 cam automatics that he inherited when he bought the company in the late 1980s and has replaced them with seven sliding-head mill-turning centres of 12/16, 20 and 32 mm capacity from Star Micronics.
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Turned parts subcontractor turns to Star
Roger Innes of Inro says that he has based his company's rapid growth over the last three years mainly on the purchase of Japanese-built Star CNC lathes through A and S Precision
Fixed-head turning capacity has been similarly upgraded to twin-opposed-spindle bar machines with live tooling, and here too Star GB has helped to maximise productivity by supplying FMB bar magazines to feed the machines.
The latest bar feeders to be delivered last year, called FMB Turbo 10-65 and 8-80, are designed for four-metre bar and the latter model is of the German manufacturer's new cast iron construction.
Vertical machining centres and a twin-pallet horizontal-spindle cell have replaced manual milling capacity to improve prismatic machining capability and profitability at the Portsmouth site.
Said Mr Iacobucci, "In 2003, one of our big customers making gas detection equipment for the oil industry relocated its manufacturing operation to China, and much of our work disappeared out there.
"Some of the simpler chucking operations and machining of castings stayed there.
However, inferior quality of machining and materials resulted in a lot of precision mill-turning coming back to us, as component reliability is paramount in the safety-critical petrochemical industry." He went on to describe another contract to produce a 52 mm long mild steel spike for a police stinger that was lost to a Chinese subcontractor.
DKW was making them for around 70 pence each, but the Chinese firm quoted 12 pence.
Mr Iacobucci pointed out that a 52 mm length of 5/8 inch diameter, EN16 bar cost 11.88 pence at the time, which meant that the part was being made for next to nothing.
Sure enough, the poor quality resulted in the contract coming back to DKW, and machining of regular 20,000 batches of the surprisingly complex and accurate component is ongoing for the British stinger manufacturer.
Other examples of components made to high Cpk values on the Star lathes include a diaphragm and stem, both mill-turned from stainless steel for the sensor industry.
The former is needed in quantities of 80,000 a year across a family of sizes while the latter, a kanban part, has to be machined to 20 microns total tolerance on squareness and flatness.
Previously, after OD and face turning, the stem would push back in the collet when trying to machine a longitudinal blind bore, and the drill would often break.
So the part had to be reclamped for second-operation drilling on a capstan lathe, which added considerably to its manufacturing cost.
The component is now completed in a single visit to the latest Star lathe to be installed at the Portsmouth plant - an SR-20RII fitted with high-pressure coolant (HPC).
DKW's engineering manager, Jerry Acres, commented that HPC greatly assists machining of stainless steel, which accounts for two thirds of the Portsmouth subcontractor's output.
Although the latest Star SR-20RII was installed as recently as November 2006, experience has already shown that surface turning speeds and feed rates can be increased by as much as 30 per cent thanks to the ability of the coolant to break up the stringy swarf and dispel the chips efficiently from the working area.
So confident is Mr Acres in sliding-headstock mill-turning with HPC that he leaves stainless steel to run unattended overnight on the new SR-20RII.
The intention is to retrofit HPC to three other similar machines on the shop floor.
In these days of fierce international competition, it is not enough to machine parts within tolerance and deliver them on time.
They must also be produced economically.
The sensor diaphragm contract, for example, was only won after serious cost-down discussions with the customer.
Mr Iacobucci therefore considers all possibilities for efficient production when he invests in new plant.
24/7 automation and single-hit machining have helped enormously compared with the old days of manually loaded, single-bar cam auto's and frequent second operations.
Ten years ago, DKW employed five staff full time for second-op work; today there are none.
As fewer operators are needed to run modern CNC bar machines, headcount has gone down overall by a quarter from 50 to 37.
HPC is starting to boost efficiency too, especially for stainless steel parts; and ever more capable machines with higher power, more and faster axes, and extra driven tool positions allow additional complex features to be machined in-cycle.
Analysing the position of UK subcontract firms like DKW compared with similarly equipped competitors in low-wage countries, Mr Iacobucci sees on the negative side higher overheads in the UK for rent, rates and utilities, and higher fixed labour costs, although these are reducing somewhat thanks to automated and unattended machining.
A neutral area is machine purchase, which like-for-like represents similar investment globally.
On the positive side, however, are the knowledge and experience of applications engineers and machinists in the UK and the high quality of work they produce, backed by rigorous inspection and statistical process control.
For smaller batch quantities, especially those delivered under kanban, line-side and similar just-in-time supply contracts, overseas companies cannot compete effectively, particularly those in Asia due to the long delivery times.
Bespoke packaging designed to avoid damaging components, which are often of high value, is becoming more important these days.
The watchword is close co-operation with the customer at every stage of the supply chain, rather than simply taking orders and fulfilling them.
Central to these arguments is machine reliability, as breakdowns alter all of the calculations.
DKW regards the uptime of Star lathes as exemplary.
The first two - an SR-20 and SR-32 - were installed in April 1997 and have scarcely gone wrong in 10 years.
Jerry Acres confirms that with routine maintenance, these and all of the other Star lathes hardly need any unscheduled attention.
"It is incredible - we are still waiting for them to go wrong", he said.
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