Filament Alignment Jig Case Study

Personal service at the heart of long term business relationship between PCML and electron beam welding systems manufacturer CVE.

Electron beam (EB) welding has become a vital joining technology in many industries, as well as making some manufacturing processes possible, in several cases EB welding is the only technology that could be used to achieve the desired result. It has also streamlined some manufacturing processes, consequently making them more economical and in other cases its deployment has allowed the use of specialist metals in particular combinations that would otherwise not be possible to weld together.

Filament Alignment Jig DrawingCambridge Vacuum Engineering (CVE) a division of Aquasium Technology Limited have unrivalled expertise in electron beam technology gained over 40 years of industrial experience.

Operating from their UK factory, near Cambridge, they design, manufacture and provide after-sales support of their extensive range of Electron Beam Welders and Vacuum Furnaces.

With almost 1000 installations in diverse manufacturing industries worldwide they provide solutions for metal joining and thermal treatment processes. They work with manufacturing projects, from concept to component solution and machine commission, ensuring project success every step of the way.

Most EB welding systems are of high value, complex in design and require long term planning and control to ensure they are delivered on time, within budget and to specification; consequently it is essential that components & assemblies are delivered to CVE on time by their suppliers.

According to Carl Dean, Production & Procurement Manager at CVE, "PCML are a key long term supplier of components and assemblies. We started working with PCML in 2000 when they first started trading and ever since day one they have worked in very close partnership with us at all times, providing a very personalised service, this high quality service ensures that we always receive our components and assemblies on time and to our very high standards".

Assembled Filament Alignment JigAt the heart of the EB welding system is the EB column and within that is situated the actual filament which produces the charged electrons. Filament life is dependent on the conditions used including beam power and the materials being welded.

Filament replacement takes less than 10 minutes including the time required to vent and re-evacuate the beam column. In the new design the process does not affect the mechanical alignment of the column which avoids the need for time consuming adjustment.

Repeatability is achieved by the filament alignment jig that ensures accurate positioning of the filament within the grid cup. Systems can be provided with interchangeable grid cups for even higher productivity.

Apart from manufacturing a range of complex individual components for CVE EB welding systems, PCML also manufactures and assembles the above critically accurate Filament Alignment Jig Assembly, Grid Cup Assembly and Filament Holder essential components of CVE EB welding systems.

The Filament Alignment Jig Assembly comprises of approximately fifty different types of manufactured components produced using CNC milling and turning centres, which have to be precisely assembled by hand in a strictly controlled way and environment. Once assembled, the Jig is then inspected and set up using a Coordinate Measuring Machine (CMM). The next stage in the manufacturing process involves the drilling of pilot holes and insertion of dowel pins to set the Jig, this has to be carried out in clean room conditions. Final inspection is then carried out with the data recorded and supplied to the customer in a Certificate of Conformity. Each Jig has its own unique identifier. The total time taken for the assembly, inspection, setting and final inspection of each jig is 13 hours. Jig assembly height accuracy to +/-0.02mm is a critical requirement in the finished Jig.

Grid Cup AssemblyThe Grid Cup Assembly comprises of approximately 14 different types of manufactured components which also have to be precisely assembled by hand using a very precise documented method in a controlled environment. Inserting and securing the individual Filament is a very delicate operation, each filament is only 0.5mm thick with an exposed working area of 1mm, consequently manipulation of the Filament within the Grid Cup Assembly is carried out using the CMM itself when setting the Filament up. The Grid Cup Assembly has to be calibrated to accept up to 6 different Filament sizes depending on the final application. Final inspection is then carried out with the data recorded and supplied to the customer in a Certificate of Conformity. The total time taken for the assembly, inspection, setting and final inspection of each Grid Cup Assembly is 2 hours. Positional tolerance of the Filament in the Grid Cup Assembly is +/-0.028mm.

According to Gavin Goates, Director, PCML, "CVE are one of the very first companies we worked with back in 2000, when we started trading, they are now one of our top customers. Both our business have grown in parallel and we recognised from day one that because of the complex high value turnkey nature of the CVE business we needed to build a very close relationship to ensure their components & assemblies are delivered on time, within budget and to specification."