Case Study: Vision breaks every basic design rule for plastic injection moulding

When high-end audio equipment specialists Rega, looked to move production of their acrylic turntable dust covers back to the UK, they specifically sought out a manufacturer with joint expertise in plastic injection moulding and tool making. In their experience quality issues often resolved quicker when core capabilities are integrated under one roof.

Rega are known for their minimalistic amplifiers, speakers, cartridges and turntables.Their philosophy to strip out ‘the unnecessary’ is a design trademark, stating ‘Mass absorbs energy, and lost energy equals lost music’.

When they first produced their dust cover 40 years ago it consisted of a clear acrylic flat top and four sides glued by hand.This proved sustainable until orders tripled and Rega placed the production with a Danish moulder.Ironically, because of the simplistic design, moulding the dust cover has historically been problematic.To hide blemishes the cover was moulded in tinted acrylic.After ten years and three tools, Rega decided to relocate production, coinciding with the need for a new tool. They sought a UK manufacturing partner who would produce the dust covers to their exacting standards.To quote Ky Gandy, Rega’s Supplier Coordinator, “Our dust cover vision breaks every basic design rule for plastic injection moulding.It has no draught, a major issue in de-moulding. It has sharp corners and edges, when rounded ones are obligatory. It is also made in clear material, demanding a faultless sheen with no tolerance for imperfection.”

Meanwhile, working with the existing tool was a struggle not least because of the design constraints, but Rutland Plastics discovered that two processes in the making of the tool had been skipped: a). the tool comprises a number of plates and these had not been positively located and b). the tool had not been hardened and tempered.Further compounding the quality issues - the type of tool steel used lacked a high carbon rate.To improve the quality, the steel was polished to a fine high gloss finish and this allowed for an interim supply until the completion of the new tool.

Leveraging technical resources across all departments, Rutland Plastics came up with a solution and proposed replacing acrylic with a polystyrene material that would match the look and quality that Rega wanted whilst delivering cost savings.To improve manufacture the design team instigated a number of subtle design revisions to the dust cover and the revisions were validated using 3D prints, “Rutland Plastics’ ability to show the redesign vision in a clear tangible format was a huge bonus for us agreeing to the adaptations”, confirmed Ky Gandy.

Summarising the project for Rega, Phil Freeman Company Coordinator commented, “Rutland Plastics persevered where many would have thrown the towel in. The net result is a wonderful product and I am proud of what we have achieved.It is a special moulding requiring the specialist know-how and application.We are engineers, we look for equally skilled supply partners”.

Rutland Plastics have always operated a tool room offering a comprehensive suite of tooling services from design through to routine maintenance and refurbishment.Recently the tool room has expanded and is now housed in a new bespoke 504 sq. metre facility.

Meet our team at Manufacturing & Engineering North East, stand D7, to discuss your requirements and see a diverse array of parts we injection mould.

Not attending the exhibition? call us direct on: 01572 723 476 or visit www.rutlandplastics.co.uk