UK precision machinist overcomes Chinese let down

When a Chinese machinist failed to deliver the level of quality required for special bar taps made from 316 stainless steel, it was a recommendation from another customer that brought R E Enfield to the rescue to produce a batch of 16,500 tap assemblies each comprising eight parts.

Says managing director, Derek Enfield: "You cannot afford to let customers down today. Reliability is the key to survival in the subcontract game and you have just got to invest in the right capital equipment to service the customer and this was a perfect example that has secured us future business."

Mr Enfield is 73, but firmly believes business is about service and unlike many company owners at his time of life, has not even contemplated the thought of exit strategies into retirement. He is intimately involved in his company’s continued success and investment plans and says: "You need to invest in the type of equipment that will perform the task with that ‘little bit to spare’ and then use the in-house skills to deliver the quality, as promised, and at a reasonable price that is acceptable to both parties."

The failure to be reliable was a reason Mr Enfield changed his machine tool supplier to C Dugard of Hove three years ago when he installed his first Dugard Eagle 1500 Maximill vertical machining centre. The machine was purchased to produce parts for the medical, bar code reader, calibration equipment and electronic machinery sectors and was far from being a retaliatory or impulsive buy, having been let down by the previous supplier of several machines to his workshop. He looked at all the main contenders in the machining centre community, commenting that he could not believe the arrogance of some suppliers and the lack of willingness to look at the wider overall package or really believe in his long term plans.

Here C Dugard were keen to work with us he says – they clearly understood our needs and the aftersales has been as good as their word. With the Dugard Eagle subsequently proving its worth and reinforcing the decision to change suppliers, further installations followed: an Eagle 32 sliding headstock mill/turn centre with subspindle in 2005, an Eagle 660 vertical machining centre in 2006, an Eagle 850 vertical machining centre in 2007, with another machine about to be ordered.

Indeed, such is the company’s success that R E Enfield is also about to be recorded by a Bank of Ireland film team to appear on its new website as an example of how having the right investment strategy pays dividends.

The company has not always been involved in subcontract machining; its history spans prototyping, special purpose machining, roll manufacture, light fabrication and dynamic balancing. Until 2004 it made over 3,000 machines for use in film processing and still produces components for machine assembly elsewhere. It also fabricates and assembles parts to meet medical contracts. Around 20 per cent of production is exported to America, Italy and Germany although a progressively weakening dollar is beginning to concern Mr Enfield’s wife Susan who manages the commercial side of the business.

Mr Enfield’s investment in plant and equipment has followed the trend towards smaller quantities requiring higher flexibility to produce batch sizes of mainly between 100 and 200 parts. The complexity of parts produced also varies between the very simple to the highly complex, involving multi-feature components with tight tolerances and surface finishes, and cycle times that tend to vary from between three minutes and 70 minutes. Following his customer service philosophy, the machine shop tends to run on a single shift but when needs dictate, his foreman and operators will work out their own rota and run 24 hours. "We are that type of company," he maintains.

Each Dugard Eagle is also fitted with the optional Siemens control system about which Mr Enfield is full of praise, the ease of programming of its ShopMILL software he says: "Is extremely user friendly." The parts produced, mainly from aluminium on the machining centres, contain a whole host of features with multiple drillings and tappings, breakthrough holes, milled slots, and a considerable amount of pocketing. Many of these components must also be blemish free, often being anodised and individually wrapped for despatch.

A move to install CADCAM in a separate office is currently on the cards for the more complex parts in order to help improve machine utilisation. However, editing will still be performed at each machine and here, by following Dugard’s advice, he has a good level of control software standardisation which he considers to be very important.

On the Dugard Eagle vertical machining centres, multiple vices are in constant use and, harping back to its special purpose days, location plates tend to be produced to enable several parts to be machined at the same loading. This method of working extends floor-to-floor times before the need to stop for reloading. Renishaw probing has also been incorporated to aid the datuming of tooling.

The seven-axis 22 tool sliding headstock Dugard Eagle 32 was installed to machine a special stainless steel spindle for a brewing customer and this is produced in ‘one-hit’ using the main and subspindle. The cycle involves turning, contouring, the milling of several flats via the Y-axis crossfeed, cross hole drilling and precise machining of seal diameters and blended radii. This part was described by Mr Enfield as having very tight tolerances and surface finishes that would normally be ground but here the Eagle 32 is able to prove how precise and repeatable it is.

Indeed, said Mr Enfield: "I really must praise this machine for providing such consistency in a very difficult material. The only drawbacks are the problems associated with the 316 stainless steel where our operator has to keep a very wary eye on the swarf."

Materials generally machined for his 15 very active customers, tend to be mainly aluminium, brass, plastics and 316 and 303 stainless steel. For one particular sector, the food industry, R E Enfield supplies special calibration test sticks that are produced in 340 different sizes from 0.2 mm diameter which Mr Enfield admits he has a job to see, let alone machine. Each test stick has to be marked using a CNC engraving machine and this he describes as a prime example of the diversification of work in which his company has become involved.

The security of our company has been built upon achieving what we promise," he insists. And follows on to predict: "We are expecting more business to return from China, it is only a matter of time before buyers realise there is far more involved in a supply relationship than a low, bottom line price."

http://www.dugard.com