Savings all round with metal replacement programme

A recent application of this technology involves the supply of a cover and display window insert supplied for the VP50 range of electronic pressure controllers manufactured by Norgren Ltd in Leeds. These controllers are designed to turn a variable electrical input (voltage or current) into a proportional air pressure output typically used on positioners or speed controllers for machine building projects.

Typical advantages of these metal replacement products include savings in weight, reductions in material costs and simplified manufacturing compared to metal equivalents. It was important that the replacement products did not compromise the high performance characteristics of flow, accuracy and response times of these controllers.

The components provided include a square shaped cover, manufactured from a high specification engineering polymer, which was designed to protect the electronic components. This cover, moulded with a textured surface finish, incorporates an aperture providing visual access to an illuminated digital display of control signal input and output pressure. The aperture is sealed with the second component being a clear polycarbonate window incorporating a simple clip-in fitting, used in conjunction with a shaped rubber gasket. Positive sealing to IP65 (or higher standard), was necessary to provide adequate protection for the controller electronics against the potentially damaging ingress of moisture or dust.

Will Feehally, Project Leader for Norgren quoted, “As well as achieving the cost savings required, we have eliminated difficulties associated with casting the precise shapes we required for the metal cover. In addition it would have been necessary to glue and seal a rubber cover over the display aperture, an operation that was not conducive to simplified manufacture. However, the technical team from O F Bell provided useful consultation input on the design and manufacture of the metal replacement components. Their advice in the early stages of the project, combined with their flexibility to accommodate even 11th hour modifications has been instrumental in achieving a good result. We were pushing the boundaries on some of the initial design concepts and the O F Bell company successfully steered us to the point where we were able to develop a product which technically could not be achieved in metal. Savings of 50% were achieved on the component cost, coupled with efficiency improvements in the assembly process. Combined, this has ensured that the tooling costs for the mouldings provided will be recovered in less than 12 months.”