Two re-engineered EDM machines have significantly reduced operations for complex parts from eight or ten operations down to only one or two operations for an engineering sub-contractor.

Since acquiring two Sodick re-engineered EDM machines from Sodi-Tech UK, Barrow, UK-based Strand Engineering North West has managed to significantly reduce machining operations for complex parts - items that previously required eight or ten operations can now often be completed in only one or two operations. Barrow-in-Furness, South Cumbria, is a town with a long and proud history in shipbuilding and engineering. Today, this industry has contracted considerably from its heyday, but it is still responsible for creating some of the region's most talented engineers.

Doug Martin, managing director and majority stakeholder in Strand Engineering North West is no exception.

He started as an apprentice fitter and turner at the engineering works of Vickers (as it was then known) back in 1965.

Following completion of a degree in mechanical engineering from Salford University he went on to become machines manager then technical manager of the Vicker's Engineering Works, responsible for 900 personnel at the company's peak.

However, as the shipbuilding industry gradually declined, Martin's ambitions began to take another course.

Some 13 years ago he decided to trade-in his managerial role for that of owner and founder of a small engineering subcontract manufacturer called Strand Engineering North West.

Today, his fledgling initiative has grown into a 24-employee, GBP 1.5 million turnover business serving prestigious customers in the defence, power generation, process and railway industries.

Taking a progressive approach to achieve growth, Martin has always believed in investing for the future.

For example, approximately two years ago, Strand decided to invest in EDM, a new technology area for the company.

'We wanted wire cut and die sink EDM machines to allow Strand to produce precision components of a complexity not previously possible at the firm,' said Martin.

'We asked around the industry and were advised from several users that Sodick machines were good quality products available at reasonable prices.' Duly convinced that Sodick could provide the technology required, Sodi-Tech UK set about supplying Strand with two re-engineered machines from its extensive stocks - a CNC A500W wire cut EDM and a CNC MOLDMAKER 3 die sink EDM.

'The machines have helped cut lead-times tremendously,' explained Martin, 'Particularly on prototype and small/medium batch components.

Because we need to produce precision, complex parts with tight tolerances, some components could take up to eight or more operations using traditional milling, drilling and boring techniques.

However, with EDM, especially wire-cut, this can often be reduced to a maximum of two.

When a customer requires a quick response, the Sodick machines are invaluable.

Our acquisitions have also allowed us to pursue work that would have been beyond our capability previously.

For instance, we are now actively seeking contracts within the medical sector involving EDM wire-cut and titanium welding.' Today, Strand uses its Sodick machines to process components from a wide range of materials including steel, stainless steel, aluminium, bronze, titanium and brass, etc The company's accumulated expertise has allowed it to nurture an impressive list of blue chip clients that include bae systems and major companies in the oil, nuclear and transport industries.

Defence projects constitute a significant slice of Strand's order book.

Recent systems and components have been supplied for the AS90 Self Propelled Gun, the 4.5 Mark 8 MoD.1.

naval gun for warships, the deep hoist system for ammunition on the Type 45 destroyer, the M777 lightweight howitzer for the US, the Terrier tank/bulldozer for battlefield engineers and the Astute nuclear submarine programme.

As well as machining operations Strand also offers fabrication, fitting, blast/paint, assembly and testing services, however, Martin said it is the company's attention to providing quality that sets it apart from its competitors - Strand is ISO9001:2000 registered.

'Accuracy is crucial to our customers,' he said.

'We are the only subcontract manufacturer in the Barrow area with EDM and computerised co-ordinate measuring machine (CMM) capability.

Our Sodick machines and our CMM help us put the emphasis on quality, despite the fact that we operate in a very price sensitive sector.' Martin added that the ease-of-use offered by the Sodick machines has helped keep costs down.

He says that training was straightforward and that only one operator is required to run three machines - the two Sodick models plus a CNC mill.

And though Strand only operates a single shift system, the company sometimes leaves its wire edm to run overnight unattended, helping to gain further competitive advantage.

EDMs Using the flexibility of the Internet for remote access and machine management of its nine wire EDMs will give a subcontractor very effective communication with the machines' control systems.

Blantyre (Glasgow)- based Scottish specialist spark erosion machinist, The Spark Erosion Centre, is set to take its adoption of EDM technology to new heights and harness the availability and flexibility of the Internet for remote access and machine management of its nine Fanuc Alpha Robocut wire EDMs. At a stroke the adoption of this method of working will enable very effective communication with the machines' control systems to manage events and see in real-time the exact state of production affairs and, when appropriate, enable corrective action to be taken. 'This development will springboard our company even further ahead of the competition,' maintained co-director Bill Brynes, 'And it will be particularly useful when the machines are running unmanned at night and over weekends, as is usually the case.' It is no coincidence that the battery of Fanuc Alpha wire cut machines underpins The Spark Erosion Centre's established reputation for the responsive supply of cost-effective wire eroded parts to a wide range of customers throughout the UK.

The company has just installed its ninth machine, a Fanuc Robocut Alpha 1-iC with a 410mm Z-axis and extra large work tank to extend its capacity for larger work.

According to proprietor David Gilbert: 'The progressive installation of Fanuc machines has been maintained because they prove to be very reliable, represent value for money and, importantly, have always produced the high-class components we have demanded.

Over the years we've never been shy about investing in the latest Fanuc technology from 600 Centre to enable us to cut faster and to work smarter and better.' Working smarter is definitely the way to describe the addition of the remote access using the Internet, to which Brynes added: 'Having the ability to remotely interrogate each control system will be indispensable when, for example, a machine is working unattended on large capacity workpieces.

These can be up to 300mm thick, and cycles sometimes demand a week of non-stop cutting.

Without such access, we could easily lose a weekend's production if there is a fault and the machine stops,' he said.

The conviction that Internet access is the ultimate in harnessing unmanned control of a machine is further evidence of how the Scottish team has never shied from harnessing the latest wire erosion technology to gain production benefits.

With its roots stretching back 25 years to the manufacture of mould and press tools - an activity it continues today - the company's use of the spark erosion process has continually evolved in tandem with machine developments.

This has been taken advantage through a progressive investment strategy in more powerful and more capable machine installations that have been subsequently traded-in for the latest machines with even more advanced features.

'We have come a long way from the early punch-tape controlled units,' said Brynes, 'And we have a track record of being early adopters of, for example, machines with automatic wire feed and submerged cutting as well as the progressive development of increased cutting speeds.

Program management for all our Fanuc Alpha machines is based on a PC network, which will be fully utilised when our plans for Internet access are finalised.' The three latest installations at The Spark Erosion Centre of two Fanuc Alpha O and the recent larger capacity 1-iC Robocut from 600 Centre of Shepshed near Loughborough typify the level of performance-seeking technology currently available from the company's wire cut stable.

With the latest machines The Spark Erosion Centre is able to cut at rates up to 330mm2/min using 0.3mm brass wire and carry out a fully automatic wire feed while submerged on work pieces up to 100mm thick inside 12s.

By using thermal melting this is some 20s faster than the previous generation Fanuc machine.

The thermal melting extends the reliability of the machine through a much simpler process and the annealing effect of the heat generated improves wire straightness and creates a very sharp edge at the point of cut.

With thermal melting wire disconnection takes just four seconds and reconnection eight seconds and the process eliminates any need to drain and refill the tank.

The Robocut Alpha-1i features Fanuc FS 180is-WB 5-axis control and the latest TR1600 non-electrolysis power supply.

This prevents surface corrosion on the parts and, by reducing the heating effects on the re-cast layer of the material being processed, the surface does not soften around the cutting area.

Indeed, surface roughness better than 0.08 micron Ra can be achieved using the micro-finish power supply In addition, with the latest AI corner control, wire deflection is minimised giving more precise path control that is important to The Spark Erosion Centre to ensure maximum profile and corner accuracy.

Indeed, with the latest machines, advances in the technology means they are capable of holding roundness to within 1.2 microns on a 30mm hole.

Latest machine enhancements also overcome problems when cutting into an edge of a workpiece, for instance, which leads to wire breakage and subsequent delays.

This is often caused through an unstable dielectric supply that can also oxidise the surface of the component.

Both these problematical areas are overcome with the latest Fanuc A1 Cut-in function that automatically adjusts cutting conditions and dielectric fluid pressure.

As a result, each entry into a new cut is smooth and stable.

Once in the cut, the Fanuc Nano Interpolation software is able to distribute positioning commands from the NC control with a pitch of 0.001mm (one nanometre) to each of the axis servomotors.

As these are fitted with ultra-high resolution 16 million pulse coder feeds, any accumulation of axial movement error is eliminated thus maintaining a very precise and smooth feed rate.

* Latest adaptive control software - the latest adaptive control software is able to detect any changes in workpiece thickness and automatically adjusts the process settings to maintain cutting efficiency and thus avoid wire breakage.

This feature can improve cutting speeds by up to 30% at the Blantyre company compared to conventional methods.

With similar cutting rate, control and generator capabilities, the Fanuc Robocut can accommodate workpieces weighing one tonne and handle a 16kg bobbin of wire giving some 125h unmanned running when using 0.2mm diameter wire, 80h with 0.25mm wire and 55h with 0.3mm wire.

Multiple operations in a single set-up on multiple-loaded parts, and the machines' control technology, were both highlighted by Brynes as being especially useful.

'While multiple loading enables us to make maximum use of the working area of each machine, the control functionality provides us with a precise insight into cutting speeds and cycle times.

This means we can price each job very accurately,' he said.

Like their stablemates on the 19-employee company's 10,000ft2 site, the Fanuc Robocut Alphas are kept busy producing a varied mixture of parts in predominantly 316 stainless and Inconnels as well as brass, bronze and other exotic materials.

Quantities span single parts to batches of perhaps 100 or more for a wide range of clients across the oil industry, aerospace and electronics sectors.

Workpieces can include very thin parts, since the wire erosion process imparts no forces, as well as very intricate electrodes from tungsten copper, parts for sporting guns and components from solid billets, with both external and internal blends and curves.

The shopfloor is also home to spark erosion and toolmaking sections, as well as a battery of plastic injection moulding machines that offer a trade moulding capacity as well as own-product manufacture of the likes of caps and spacers, to the construction industry.

'Our business is all about customer service,' concluded Gilbert.

'We really do not know what will come through the door next, so having the variety and flexibility of the nine wire erosion machines gives us the resource to be able to respond quickly with high-calibre parts at the right price.

That is what our customers want - and, indeed, it is exactly what we want from our suppliers.' He continued: 'That is why we've always returned to 600 Centre for wire edm as well as a Joemars 325DZ EDM drill.

The level of service provided by 600 Centre has always been impeccable, and in our world of sub-contract supply where customers place increasingly demanding requirements on component complexity, delivery and price, having that comfort factor is indispensable.' But, he reacted: 'Our customers' demands remain as stringent as ever'.

'Even if they continue to move the goal posts we know that by using machines of the calibre of the Fanucs, we will remain at the top of the league.'

A specialist EDM subcontractor that sports many prestigious aerospace approvals, including NADCAP Rolls-Royce and Dunlop, has accumulated a shop full of Sodick wire EDM technology.

A specialist EDM subcontractor that sports many prestigious aerospace approvals, including NADCAP Rolls-Royce and Dunlop, has accumulated a shop full of Sodick wire EDM technology that now includes two of the latest AQ535L linear machines. Coventry-based Hi-Tech EDM Services was formed in 1981 to provide a complete EDM service to industry. Some 25 years on the company has developed its niche expertise and attracted a host of blue chip client approvals: including Rolls-Royce, Dunlop and Goodrich in the aerospace sector, as well as many others from industries such as Formula One (Mercedes Benz High Performance Engines).

The company is also AS 9100:Rev 3B accredited and has NADCAP (National Aerospace and Defence Contractors Accreditation Program) approval from the US.

This, suggests co-director Bob Duffin, was particularly arduous to attain, in terms of both time and money, but has paid dividends.

Hi-Tech is now NADCAP approved to undertake wire, die sink and hole drilling EDM operations.

As he points out, few tier 2 suppliers in the UK can boast the same level of accreditation.

Achieving and maintaining such demanding manufacturing and quality standards requires EDM technology of the highest precision and repeatability, which are two of the reasons why Hi-Tech has been using Sodick wire EDM machines for the past 15 years.

And the company's commendable programme of investment has been boosted further by the recent arrival of Hi-Tech's second AQ535L, a four-axis wire edm with linear drive and automatic wire threading technology that can accommodate workpieces weighing up to 680kg.

This latest acquisition brings the total number of Sodick wire machines on site to eight.

'I think we can now rightly call ourselves the largest EDM subcontractor in Coventry, and also one of the largest in the West Midlands,' says Mr Duffin.

'I've been using EDM machines since I was 19, but when I saw the linear technology from Sodick, I knew it was a real step change.

The machines are quick, accurate and reliable, and as an added bonus, provide extremely low day-to-day running costs, which is increasingly important in an age where energy prices are climbing rapidly.' Hi-Tech has to adhere to a Rolls-Royce maintenance schedule, which entails frequent machine checks, however, Mr Duffin says that his Sodick machines do not let him down.

'On the rare occasion we have to call Sodi Tech for support they are always very quick to respond - overall I am very impressed with the service I receive.' The new AQ535L was acquired by Hi-Tech to help the company win a contract for cutting up large aerospace rings (up to 2000mm diameter) into segments, although this particular job is perhaps not typical of the work undertaken.

Many jobs are complex parts, such as turbine blades, nozzle guide vanes and fuel/air swirler plates, requiring two or three fixture orientations to complete - all parts are programmed off-line.

The Sodick machines have also proved crucial in the production of small diameter cooling holes and narrow strip seal slots in turbine blades and NGVs.

Typical materials processed include nimonics, titanium, stainless steels and carbides, as well as jet heat and honeycomb composites.

Batch sizes vary from one-offs up to 50.

Sodick's linear motor technology provides instantaneous servo time that maximises cutting efficiency.

Since there are no ball screws or couplings, backlash is totally eliminated.

This provides several advantages, including improved positioning and cutting accuracy, while providing smooth and vibration free table movement.

'We tend to load short runs during normal day-shift hours, but one of the best features of the AQ535L is that we can leave the machine to run overnight and at weekends for longer running jobs,' he says.

'We only pop back to change wire and very rarely get a problem - the accuracy [typical tolerances at Hi-Tech are around 0.005mm] and surface finishes achieved are superb.

All-in-all the machines never stop running.' The structure of Hi-Tech is a blend of the age and experience of the two founding partners, who together can claim 70 years EDM experience, and the forward thinking and exuberance of their supportive young technical operators.

Other work processed regularly at Hi-Tech includes tungsten carbide heading, extrusion and powder metallurgy compacting dies, as well as press tools, plastic moulding tools and forging dies 'A good proportion of our success can be attributed to our investment in the latest technology,' concludes Mr Duffin.

'Considering our size we have invested heavily, which has helped us win and retain more contracts.

We have a nice order book now, a pleasing reality in which the Sodick machines have played a very prominent role.'