News

Graphite EDM Electrodes

Erodex Design Services

Friday 30th November 2018

Since the early 1970's, Erodex has been providing a fast, first-class engineering service to the aerospace sector. The acquisition of BWP in 2008 has allowed The Erodex Group to offer a full project management, procurement, build and certification services, making the company a one-stop-shop for a client’s design, tooling and EDM electrode needs. All aspects of any project are managed by a team consisting of seven experienced designers, dedicated project planners, administrative staff and more. This allows for a streamlined process, optimum technical solutions and shorter project lead times.

This approach has led to Erodex becoming trusted suppliers to some of the world's leading aerospace original equipment manufacturers, often operating as an extension of a customer's own design team. In this article Paul Tardif, Design Manager at Erodex, explains in greater detail the role that the Erodex design team plays in providing design solutions to a range of unique engineering challenges posed to them by clients.

"Primarily, we are a tool design office, specialising in aerospace tooling and the design of EDM electrodes, to make various jet engine components and to enable the mass production of parts. We are currently working on a range of new engine projects and new part introductions for some of our major customers" explains Paul.

"The designs are primarily one off, unique designs - almost like prototype tooling, meaning that we specialise in working on new parts that are being introduced, new engines being developed or modifications to improve existing tooling. Once we have designed the tooling and it has been manufactured, this can be in service for up to 20 or 30 years. We often hear of tools that are still being used that are based on 25 year-old designs. These could be grinding fixtures, EDM electrode holders, assembly tooling, turning fixtures or part marking tools for example".

Much of the ‘added value' created by the Erodex design team includes developing solutions to complex problems, finding new ways to make existing processes more efficient and design solutions that enable a high degree of accuracy and repeatability to be achieved. Paul adds "the accuracy required for the grinding tooling for example is to grind within under +/- 0,025 of a millimetre in terms of mass production tooling, requiring around +/- 0,01 in terms of the accuracy from our tooling. The customers can then use semi skilled labour to load the components into the tools and can expect a really high level of repeatability, always knowing exactly where the component will sit, and how it is going to clamp. The component would often be expected to repeat to that same position within a 0,02 of a millimetre every single time.

"Our experience designing tooling for holding turbine blades, vanes and holding awkward parts makes us uniquely placed to deal with complex forms and devise how to locate and hold these, so that they can be machined successfully. We are familiar with most component geometries involved at the design stage, and all the tolerances that need to be achieved. With a particular speciality in EDM tooling and seal slot tooling, we have a deep understanding of the pitfalls and problems typically encountered working with or manufacturing graphite components, and the way they function in the EDM cycle."

The Erodex design team consists of 3 design professionals in its Halesowen based head office and a further 4 based in Bournemouth. After previously acquiring an integrating BWP Technical Services into the Erodex group, the team has worked closely with the existing in-house manufacturing facilities throughout the Group and built on their existing and illustrious track record of working with leading names within the aerospace industry, dating back as far as the 1960's.

Paul continues: "Over the next 12 months, we have numerous engine blade projects coming up with leading aerospace engine manufacturers. One project could easily span 3-4 months, with multiple projects often operating simultaneously.

"We like to think of ourselves as specialists in finding solutions to complex design challenges. For example, previously we worked on a project for a client that was manufacturing an engine component which had 20 blades attached to its hub. To identify any imperfections or cracks in the welds where the aerofoil blades join the central hub, the whole disk was required to be lowered into a bath of acid and rotated for a few minutes.

"We were asked to find a way of being able to rotate the part in an acid bath but in a controlled way, not only to achieve a more consistent result, but also because of the health and safety implications of a previously manually operated process.

We had to grip on the very edges of the blade tips, having no metal to metal contact and rotating at a consistently slow speed. What added to the complexity was that there were two variations of these components and we were asked to design and manufacture one fixture that would accommodate the two different sizes. These parts were 1.5 metres in diameter and weighed between 300 to 400 kilos. We found a way of trapping the component within special segments that would slip over the edges of the blades, which then went into a ring that rotated within a frame. The unit could then be lowered into the tank from a loading station with the component trapped right on the very edges of the part, then rotated before it was taken out to dry. After working closely with the customer and developing the solution, it was a major success and the tooling has been in constant use by the customer ever since".

Historically, Erodex was renowned for the manufacture of carbon and graphite products for the aerospace industry. The acquisition of BWP, which already designed EDM equipment and electrodes, allowed the group to combine the extensive graphite machining experience of Erodex with BWPs extensive knowledge of designing fixtures for aerospace parts. With a fantastic track record for reliability and a history of problem solving for clients, it is no surprise that Erodex have become integral partners to many of the world's leading names in the aerospace sector.

For more information on how you can benefit from Erodex Tooling Solutions, contact sales@erodex.com or +44 (0)1384 892011

By submitting the above information, you consent to your information being used for the purpose of contacting you. Information on how Erodex handles your data can be found here