A dedicated manufacturing cell, comprising four automated high speed grinding machines is playing a crucial role in helping Dawson Shanahan – a specialist cold forming and precision engineering company, improve the accuracy of finished parts and levels of productivity for components supplied to customers in the medical, automotive and electronics industries.

Developed in conjunction with Earlsdon Technology (E-Tech), the grinding machines use specialised tooling to achieve surface finishes with tolerances that the company believes are more accurate than anything previously available on high speed systems of this type.

Dawson Shanahan is one of a small number of independent engineering companies to specialise in both cold forming and precision engineering using a wide range of conventional machine tools. The company has production centres in Potters Bar and Welshpool and designs, produces and supplies finished components to customers throughout industry and around the world, with almost 80% of its sales being exported.

The E-Tech grinding machines include groove, slot and centreless grinders and have been installed as part of an ongoing development programme to increase manufacturing capacity, especially for precision parts that are often based on high performance steels or other exotic engineering materials. Jeff Kiernan, commercial director at Dawson Shanahan, explains: “We’ve seen a considerable increase in demand in recent years from customers looking for component parts produced to ever tighter tolerances – often to within a few microns – for both small batches and large volume production runs. As a result we needed to expand our machining facilities, especially our grinding cells, to increase productivity while enhancing levels of quality and repeatability still further.”

Dawson Shanahan has worked closely with E-Tech to develop the new slot, groove and centreless grinding machines. Wherever possible, these use common features to simplify operation and maintenance – for example twin grinding spindles with dressable and demountable Cubic Boron Nitride (CBN) vitrified grinding wheels, plus automatic part feed and orientation systems, using standard bowl feeders and pneumatic air conveyors.

Key to the successful operation of the machines has been the development of special purpose CBN grinding wheels carried out by both companies in conjunction with the grinding wheel manufacturer, Asahi Diamond Industrial. The 400mm diameter wheels typically operate at speeds of 4,000rpm and are automatically balanced, to eliminate vibration, and dressed during operation, with the latter using in-situ diamond dressing wheels to maintain exact outer edge profiles and a long operating life.

Machine control is via standard Siemens touchscreen PLCs, using bespoke programming, which also provides the facility for detailed diagnostics, with data being downloaded for review as part of Dawson Shanahan’s quality system.

Dawson Shanahan
www.dawson-shanahan.co.uk