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.'