Excel Precision Group (EPG) has enhanced its wire and spark erosion capabilities by investing in two new Sodick machines supplied by Sodi-Tech EDM (
www.sodi-techedm.co.uk).
Installed at the company’s Gloucester facility, which has AS9100 rev D and NADCAP AC7116/3 Rev B approval in place for both spark and wire erosion, the Sodick ALC600G wire EDM and AG60L die-sink EDM machines will underpin important contracts in both the civil and military aerospace markets.
Established in 1978, EPG operates from two modern facilities in Gloucester and Leeds, which together house over 30 CNC wire and spark erosion machines.
This capacity — along with its accreditations — makes EPG one of the leading EDM sub-contract operations in the UK, with particular emphasis on aerospace and defence.
Steve Batt, operations director at the Gloucester facility, said: “Few EDM sub-contractors have both AS9100 and NADCAP approval.
“This level of process control allows us to serve an extensive number of aerospace and defence customers.
“In addition, we currently hold company approvals from BAE Systems, Rolls-Royce, Goodrich, Safran Landing Systems, Dowty Propellers, Messier Dowty, MT Satellite, GE Aviation, Moog Aircraft Group, UTC Aerospace Systems, Mettis Aerospace and Triumph Actuation Systems.”
Along with the need to replace older machines, the company’s investment in Sodick technology was partly due to the imminent ramp-up of a defence contract that is currently scheduled to run until 2022.
A non-disclosure agreement has been signed, but the parts involve the intricate wire erosion of titanium stock.
Working with titanium
Mr Batt said: “We looked at both Sodick and our existing supplier of EDM machines, but the test cuts provided by Sodi-Tech EDM were simply better.
“In particular, the surface finish produced by the AG60L spark eroder really caught our attention.
“Due to the presence of debris, some machines struggle to replicate the surface finish achieved on the sides of parts, on the bottom face. However, this was not an issue for the AG60L.”
EPG’s AG60L has been set to work producing a variety of aerospace parts, including stainless-steel actuator components. In total, the aerospace sector occupies about 40% of the machine’s time.
The other Sodick machine, the ALC600G wire EDM, has around 50% of its output sent to aerospace customers, including the titanium defence part.
Mr Batt said: “Compared with our old machines and process, using the ALC600G has transformed our operation for this component.
“For a start, we previously needed two machines, whereas now the part is completed in its entirety on the ALC600G.
“Also, our old machine would only achieve a 90% pass rate on an angled face with a 5µm tolerance.
“With the Sodick machine, the pass rate is 100%.
“That step-up in quality makes a real difference on high-value-added parts such as these.”
EPG is currently tasked with producing 200 of the titanium defence parts every month, although this figure will shortly rise to 600.
Using the ALC600G, the company can produce around 24 per day.
However, with the company also working for other sectors, both Sodick machines run for 24hr, four days a week, with long-cycle-time jobs loaded at the weekends.
Aside from aerospace and defence, the company serves further high-end industries such as motor-sport, nuclear, oil and gas and medical.
Mr Batt concluded: “We’ve not had Sodick machines at Excel since before 1995, but we’re very pleased to switch back.
“The technology has moved on considerably, and we cannot fault the machines or the team at Sodi-Tech EDM, who have been very supportive since installation in early 2019.
“Through our own mistake, we once accidentally set off the fire extinguisher on the AG60L, but the response was excellent, and we were back up and running the next day.”
EPG actually began life in Leeds, but it started the Gloucester operation seven years ago, through an acquisition.
The machines there were around 20 years old, so the company has since been progressing its way through a steady replacement programme.
Mr Batt said: “One thing we’ve noticed is the compact nature of the Sodick machines.
“We were able to fit both of them into the space previously taken up by one older EDM.
“Also, while we didn’t buy the machines for speed, it’s difficult not to notice the gains we’ve achieved.
“The titanium defence part previously had a cycle time of 65min, but it is now completed in just 35min on the ALC600G wire EDM — a 46% improvement.
“As for the AG60L die-sink machine, the results we get — particularly on deep cavities — are like nothing we have experienced before.
“We have also reduced our electrode consumption dramatically; we can now complete many jobs using just one electrode.”
Good growth over the past two years has seen EPG hit an annual turnover of £2 million, and more growth is expected.
Mr Batt concluded: “There are many factors that set us apart from our competitors, not least the capacity we offer and the accreditations we hold.
In addition, we believe that the level of work and service we provide is ‘second to none’.
It is all about quality, on-time delivery and customer communications — backed up by investing in the latest technologies.”