Leading precision subcontractor, Colt Precision, has invested in a Doosan DNM 6700 vertical machining centre from Mills CNC to help it diversify away from its reliance on the medical market. PES finds out more.
Tewkesbury-based Colt Precision’s new investment – a Doosan DNM 6700 with the latest Fanuc 0iMP control, was delivered and installed at the company’s 7,000ft² facility in Tewkesbury in May 2021, and was also supplied with a Nikken 5AX 201FA (5-axis) rotary tilting table to help increase its capabilities and wide application potential.
Since being installed the DNM 6700 has been used to machine a range of high-precision and, often highly complex parts for the medical device, defence, aerospace and general engineering sectors.
These parts, made from a diverse range of materials including stainless steels, steel, aluminium, titanium and plastics are machined, in relatively small volumes (including prototypes and one-offs) to exacting tolerances and surface finishes.
Although the machine was delivered to Colt in mid-May 2021, the purchasing process began some months earlier and was influenced by several factors. These included: the strategic decision to become less reliant on the medical devices sector; a commitment to continuous improvement; and the effects of the pandemic.
“When we acquired Colt Precision in 2014 our objective was to create a world-class manufacturing company,” owner and co-director, Simon Tarrant begins. “We made the decision, owing to our background and previous experience, to focus on the medical devices sector and did everything we could to grow the business, build a strong reputation in the market for precision and perfection, and cultivate a growing and loyal customer base.”
To help with its objectives the company achieved ISO 9001 and ISO 13485 certification (a QMS specifically designed for medical device manufacture) and embarked on a strategic investment programme that over the past seven years has seen it significantly improve its manufacturing capacity and capabilities.
“In 2016 and 2018 we strengthened our CNC milling operations by investing in two multi-axis machining centres,” Mr Tarrant continues. “The ability to machine parts in one hit has helped us reduce part cycle times, improve lead-times and become more competitive.”
Since 2014 the company has also invested in wire EDM and laser marking technologies, created an in-house passivation plant, improved its inspection facilities and, in 2019, it acquired its first Doosan machine tool – a Lynx 2100LSYB lathe with integrated Y-axis and driven tooling capabilities.
Widening the net
Following an internal audit undertaken in 2018 which specifically focused on company sales, the company made a conscious decision to gradually reduce its dependence on the medical devices sector.
It was clear that, with 80% of business directly, or indirectly, linked to this one sector any future reduction in demand would leave the business vulnerable. The outbreak of the pandemic proved that the company’s decision to diversify was a prudent one.
“Before the COVID-19 outbreak we had already successfully begun to diversify our operations and had won significant and repeat machining orders from aerospace and defence customers,” Mr Tarrant recalls. “The quality procedures and processes we had in place (a prerequisite of operating in the medical devices sector) combined with our commitment to best-practice and improvement proved essential in our ability to reposition the company and achieve a more balanced business.”
However, the pandemic did have a significant impact on the company’s business with many of its remaining medical device customers cancelling and postponing orders.
“Hospitals cancelled implant operations indefinitely and demand collapsed virtually overnight,” Mr Tarrant explains. “We made the strategic decision not to wait for the medical market to improve and instead got on the front foot to promote, digitally and through word of mouth , our expertise and range of services to existing customers and new prospects.”
Companies from a diverse range of industries and sectors requiring access to high-quality, reliable and competitively priced machining services responded to the company’s marketing and promotion so by Summer 2020 it had weathered the storm and was fast on its way to diversifying its customer base.
“Not that long ago 80% of our turnover was derived from the medical sector. It’s now more like 40%.” Mr Tarrant notes.
To consolidate and grow its position in other industries, a review of the company’s existing CNC technologies was undertaken in January 2021. To help the company move into different industries and sectors it was decided that its milling capabilities needed to be revamped and strengthened and a shortlist of potential machine tool suppliers was created.
“We have invested in a number of CNC machine tools over the years and had a good understanding of the market and what we required.”
In terms of specification, of critical importance to Colt Precision were the size and capacity of the working table, the power and speed of the spindle, the rigidity of the machine, including the spindle/tooling interface, the CNC control, the integration of a fifth-axis unit, swarf and chip management, in-process tool/workpiece measurement and proven aftersales service and support.
The Doosan DNM 6700 is a large-capacity vertical machine with 1,300mm x 670mm x 625mm XYZ axis travels, and a 1,500mm x 670mm worktable. The machine features a direct-drive 18.5kW/12,000rpm spindle with the Big Plus dual face and taper configuration, a 30-position ATC, roller LM guideways, integrated thermal compensation and the Fanuc 0iMP control with the latest iHMI.
The machine was specified with a Nikken fifth axis rotary tilting table, enabling it to be used for 3+2, 4+1 and simultaneous 5-axis machining, a Renishaw OMP60 and OTS tool and workpiece probe package for in-process inspection and measurement, and a MH500 swarf conveyor for high-efficiency chip evacuation.
“The DNM 6700 is a large, powerful machine. It is also extremely rigid, accurate and reliable,” Mr Tarrant says. “All of these attributes make it ideal for machining a wide range of parts from an equally diverse range of materials.”
The DNM 6700 is an all-round performer suited for heavy-duty machining operations, fine-finishing and long, extended machining runs.
“Mills CNC has a good reputation in the market for its aftersales service and support,” Mr Tarrant adds. “This was one of the major reasons why we had invested in our first Doosan machine – the Lynx 2100LSYB – back in 2019. When we placed the machine order it was delivered in double-quick time and since its installation hasn’t missed a beat.”
Colt Precision's desire to achieve a more balanced business portfolio has paid dividends. The company has recently experienced its most successful trading month ever in its 42-year history.
“It’s all a testament to the success of our diversification and investment strategies working in harmony,” Mr Tarrant concludes.