Oxfordshire-based SRD Engineering Ltd, a leading high-quality precision engineering specialist, recently invested in three new Doosan machining centres supplied by Mills CNC, the exclusive distributor of Doosan machine tools in the UK and Ireland.

The machines, two DNM 4500 three-axis vertical machining centres supplied with Nikken fourth-axis units, and a DVF 5000 simultaneous five-axis machining centre, were installed at the company’s facility in June.

Since their arrival the new machining centres have been machining a range of high-precision, and often complex, components in small-to-medium batches, for customers operating in a range of sectors including F1 and motorsport, automotive, electronics, medical devices, power generation and aerospace sectors. Materials range from inconel, titanium, stainless, steels, aluminium, plastics and nylon.

Typical components are characterised by their tight tolerances — often 8-10µm on ‘tied up’ features — and exacting surface requirements (Ra 0.8um or better). Part cycle times vary considerably, from a few min to over 9hr.

The parts machined by SRD Engineering are also required, in many instances, in double-quick time with very short lead times especially where the F1 and motorsport sectors are concerned. This helps explain why the company operates 24hr five-days-a-week, and why it is committed to investing in technologies that are designed to improve productivity and efficiency levels.

Mark Bonham, a director of SRD Engineering, who runs the business with his brother Paul, said: “We operate in demanding and competitive sectors where quality, lead time fulfilment and cost competitiveness are the Holy Grail. If you are weak in any of these areas, you’ll be found out quickly and won’t last long.”

SRD Engineering was established in 1989 by Mr Bonham’s father Steve, and two other business partners. As is the case with many new start-up businesses the company had humble beginnings operating, in the first instance, from small and cramped rented premises in Bicester using second-hand machine tools.

Mr Bonham said: “It was actually a cowshed, but it served its purpose and got the fledgling company off the ground.”

Despite the modest beginnings the company thrived built on the principles of delivering high-quality and competitively priced machined components to customers ‘on time, every time’. Despite some bumps along the way, that included the 2008/9 recession and the Covid-19 pandemic, SRD Engineering’s fortunes have been on an upward trajectory.

Over the last 32 years the company has changed dramatically and grown rapidly. It has expanded its operations considerably and has relocated twice, firstly in 1995 when it moved to a 2,500ft² facility, and the second in 2014, when it moved to its current location, a larger, more modern and well-apportioned 18,000ft² facility.

The company now employs 85 people and has around 40 CNC machine tools at its disposal many of them Doosan machines supplied by Mills CNC.

A constant and recurring theme throughout the company’s 32-year history, is its commitment to continuous improvement and the regular and strategic investments it continues to make in its people, its plant and equipment, and its processes and systems.

Mr Bonham explained: “To ensure that you are meeting, and hopefully exceeding, customers’ expectations you need to monitor and benchmark your business performance and address any weaknesses or concerns before they can impact on your ability to meet customers’ quality, lead time and cost down requirements.

“We have systems in place to ensure that this is a priority and our latest continuous improvement programme — Project 24 — a company-wide initiative, implemented in 2019, focused on restructuring, redeployment, training and investment. It provided the catalyst and rationale for the recent three Doosan machine tool investment.”

Project 24 helped identify a ‘weakness’ in SRD Engineering’s milling section - specifically with three older vertical machining centres which, owing to their age and through constant use, were becoming more unreliable, required consistent and costly maintenance intervention and, if left unchecked, would create production bottlenecks.

The company decided to replace them with more advanced machine tools. A majority of the 13 Doosan Lynx and Puma lathes at the company’s facility have sub-spindles, Y-axes and driven tools and its Doosan DNM machining centres have integrated fourth-axis units.

Mr Bonham said: “We are always looking to increase our machining capabilities and not just our capacity. Multi-tasking and multi-axis machine tools help increase our productivity and operational efficiencies. Being able to machine components in one hit and reduce part cycle times enable us to better meet customer deadlines.

“Furthermore, reducing the number of job set ups required to complete a job and avoiding the need to transfer jobs from one machine to another ensures that part accuracies and repeatability’s are not compromised.”

The company’s commitment to investing in multi-tasking machines is matched by its commitment to Doosan machine tools and to Mills CNC.

Mr Bonham added: “Doosan lathes and machining centres are good machines and, from a price and performance perspective, are difficult to beat. The fact that over 50% of the CNC machines we have in our facility are Doosan machines is testament to their consistently high performance and reliability.

“We are similarly impressed with Mills CNC. The company is proactive — knows our business inside out — and has, what we consider to be, ‘industry-leading’ and ‘best-in-class’ after-sales service and support.”

The outbreak of the pandemic in March 2020, as was the case with many UK manufacturing companies, had a significant impact on SRD Engineering with orders being postponed — some being cancelled altogether. However, the company, through its strong and ‘preferred supplier’ relationships with several F1 teams was able to weather the storm by being actively involved in machining high-precision ventilator parts.

The Government’s Coronavirus Business Interruption Loan Scheme (CBILS), introduced in response to the pandemic, also helped SRD Engineering.

Mr Bonham said: “Covid-19 had affected our ability to roll-out our Project 24 continuous improvement programme - but the introduction of the Government’s Coronavirus Business Interruption Loan Scheme (CBILS) combined with the upturn in business activity and its positive impact on confidence, enabled us to get our investment plans ‘back on track’.

“We approached Mills CNC with our requirements. We had previously invested in Doosan DNM machining centres with fourth-axis units some years earlier and, owing to the machines’ reliability and performance, decided to replace two of our older milling machines with two new DNM 4500 machining centres.”

The new DNM 4500s are equipped with the latest Fanuc 0iMP control, 12,000rev/min directly coupled spindles, integrated thermal compensation, LM roller guideways, 30 tool position quick-change ATCs, Filtermist extraction systems and to increase the productivity of the machines both were supplied with Nikken CNC202 rotary tables.

Mark continued: “We are keen advocates of five-axis machine tools and of five-axis machining and the way that both can dramatically improve company productivity and performance.

“In discussing our future milling requirements and production strategies with Mills CNC’s sales and application engineers, we decided that the third machine we would acquire would be a high-performance, simultaneous five-axis machining centre that would be capable of processing a range of parts.”

The machine identified was the best-selling Doosan DVF 5000 — a compact, simultaneous five-axis machining centre equipped with a 12,000rev/min direct-drive spindle, 60-tool position ATC, linear guides, an efficient swarf conveyor system, Filtermist extraction and the advanced Fanuc 31iB5 control.

Mr Bonham concluded: “We negotiated a great deal with Mills and part-exchanged our three older machines for the three new ones. Although SRD Engineering is a very different company to the one that was established 32 years ago — not everything has changed.

“We still operate on the same quality, lead time fulfilment and cost-down principles that we did when first established and our commitment to continuous improvement, as evidenced by our recent investment in three new Doosan machining centres, remains a priority.”