Excetek die-sink EDM injects finest quality into toolmaking process

The re-shoring trend is driving a resurgence in UK toolmaking driven by the promise of better quality and delivery. Among those able to provide testimony is WSM Industries, which at its plastic injection moulding and toolmaking facility in Lancing, near Brighton, is investing heavily in site development, recruitment and the latest manufacturing technologies. A case in point is the recent arrival of a high-performance Excetek ED400 CNC die-sink EDM machine supplied by long-standing technology partner, Warwick Machine Tools.

Group strength

Formed in the 1980s as a purely toolmaking company, WSM Industries is today part of a large group with over 40 sites globally, including a number in the UK. Some 54 people underpin the Lancing operation, a facility that combines next-generation technology with some of the industry’s finest technical minds.

The injection moulding presses in service at Lancing extend from 25 to 600 T in capacity. As well as providing injection moulded parts for group companies, the Lancing site offers contract moulding for a wide range of third-party customers in sectors that include aerospace, audio, automotive, furniture, lighting, marine, medical, pharmaceutical, security, transport and water treatment, to list but a few.

Providing the heartbeat of these activities is the site’s toolroom, where high-precision engineering ensures every detail is accounted for in the production of injection mould tools according to ISO9001-certified quality standards. The company manufactures tools weighing from 40 kg to 6 T.

“In-house toolmaking is quite rare in the UK these days, but we see it as fundamental to our business success,” states Toolroom Manager Carl Ansell. “As well as new tools, the toolroom is responsible for the maintenance, repair and modification of around 3,500 existing tools that operate across our UK group companies.”

Concept to creation

Toolmaking is a well-charted, detailed process at WSM Industries. During the component design stage, the company performs full design for manufacture (DfM) and mould flow analysis (MFA) assessments. Working alongside the customer, WSM then carries out a general assembly (GA) design and review of the tool. When the tool enters the manufacturing phase, production takes place in line with the approved GA, ensuring all elements of the tooling meet the customer’s precise requirements.

“Spark erosion is one of the final processes in the toolmaking process,” explains Carl Ansell. “We use this technology to spark forms in areas not accessible using milling cutters, or sometimes where even finer surface finish is required. It’s a process that offers real finesse.”

Until recently, the Lancing site operated two ageing die-sink machines made by a different manufacturer. Warwick Machine Tools supplied both models 27 years ago, but after tireless work were nearing the end of their journey. With such as impressive lifespan, WSM Industries knew where to turn for its latest investment in spark erosion technology.

Return to the fold

“We shopped around a little, more out of curiosity than anything else, but we’ve had such a great experience with Warwick Machine Tools over the years that it was always likely we would return to them for a new machine,” says Carl Ansell.

Following a full appraisal of the company’s requirements, the Excetek ED400C die-sink EDM machine was identified as the optimal solution for WSM Industries. Built to ISO9001 standards and carrying CE certification, the new spark eroder arrived in early 2024.

“The major selling point was the machine’s affordability-to-performance ratio, which is a major factor in such a highly competitive market as toolmaking,” he says. “When shopping around, we found the Excetek was around two-thirds cheaper than comparable machines from certain other brand manufacturers, which is a huge difference. We decided if the Excetek machine could meet our needs in terms of precision, surface quality and performance, why pay more? More than 12 months down the line, we have no regrets whatsoever.”

The Excetek ED400C, the smallest of five Excetek ED series models, offers travel of 400 x 300 x 350 mm in the X, Y and Z axis respectively. It can accommodate workpieces weighing up to 1 tonne and measuring up to 850 x 580 mm. Inherent precision results from the machine’s column-structure, floor-mounting design and high-rigidity mechanical frame optimised using FEM analysis. A patented counterweight structure and a high-resolution AC servomotor in the Z axis further boosts spark precision, supported by high-accuracy linear scales and high-resolution AC servomotors in the X and Y axes.

Tools of the trade

WSM’s Excetek ED400C has been put to work at WSM Industries machining components from hardened tool steels such as P20, 1.2767, H13, D2 and Stavax.

Says Carl Ansell: “We use the machine to blend surfaces or reach surfaces that are inaccessible using a CNC mill. We know that we’ll shorten the polishing process if we achieve the finest finish possible, although it obviously depends on individual customer requirements. We also use the machine for mould tool modifications and repairs, where we add material by laser welding and re-spark the cavity form accordingly. The Excetek machine is a great asset to have in-house. As a busy toolmaking and moulding shop, we like to retain key processes in-house because it provides more control over quality and delivery, which benefits our customers.”

He continues: “I can’t fault the Excetek ED400C for its precision, surface quality, repeatability or reliability. It’s also a very user-friendly machine. In fact, we usually put our younger, less experienced members of the team on the ED400C as I want them to be the ones pushing the spark erosion process forward.”

All this has been made possible by the comprehensive training provided by the expert team at Warwick Machine Tools.

“The training and level of technical support we receive from Warwick Machine Tools is second to none,” he concludes. “We’ve been working with Warwick for 27 years, which tells its own story. Their experienced team is always very responsive and professional.”