CITIZEN HELPS CROWN QUADRUPLE PROFITS IN 12 MONTHS

Within just 12 months of diversifying his highly successful prismatic machining company into one providing a small mill/turned parts capability as well, managing director Mick Purton has transformed Crown Precision Engineering.

Now this Milton Keynes based subcontractor is not only doubling turnover, more important it is quadrupling profits and is seeing a host of new customers in the USA, Mexico and throughout most of Europe all through investing in two Citizen M32 CNC sliding head autos from NC Engineering of Watford. And, such are the levels of productivity now being achieved that even more work is being won on the back of being able to reduce machining hourly rates by almost a quarter.

Like many time-served apprentices working for someone else, a sense of 'I could do better' led Mick Purton to set up his own business. Thus was born Crown Precision Engineering.

Early days led him to concentrate on the mould and die sector, producing mould tools for the plastics and rubber industries. However, towards the end of the 1990s he was looking at a business where work in the UK was increasingly disappearing offshore which left him with some hard thinking to do. He explains: "We knew we had to source work from new sectors and the only way we could do this was to modernise. Despite the tough economic climate, we replaced our 12 manual mills with six CNC vertical machining centres over the course of two years."

This adventurous move was not only timely but also important as it paid dividends with the company securing contracts from the aerospace, electronics and general commercial sectors. These new customers then began offering Crown Precision the chance to quote for turning work which Mick Purton either produced in-house or passed on to outside companies. "We really felt we were beginning to miss the boat regarding CNC turning," he says and follows on to outline: "Giving contracts to another company is fine but of course it significantly reduces profit ratios and margins and you are not really in total control of the projects, so we decided it was time to change."

To get the diversification operation rolling, Crown hired the services of its first ever sales engineer, to source work and feed the business. Within just six months, the company bought its first Citizen M32, 13-axis CNC sliding head lathe from NC Engineering.

Mick Purton explains: "Our new salesman had plenty of Citizen experience so I guess they were always going to be the favourite. But we did our homework and had a good look at other machines. We found Citizen were very strong amongst the small turned parts sector, their performance rating was very good and there were no apparent historical problems with either machine, quality or performance. Importantly, NC Engineering was able to provide us with the support we so obviously required."

The purchase of the M32 was on the back of an export contract to supply large quantities of precision washers. Required at rates of 25,000 a month, and predicted to last for the next four years, this contract was the decider for Crown to make the plunge. "The revenue this contract would generate meant we could buy the M32 and draw back some of the work we were subcontracting," explains Mick Purton. "It was also an ideal job to start our CNC turning learning curve. Although tolerances were not over tight at + 0.05 mm, the surface finish requirements were highly critical, this was why we needed the high surface speed capability of the M32. While the part is relatively simple, once set, the machine just runs and runs. As the labour content is minimal this makes it very competitive."

No sooner had Crown installed its first Citizen M32 when the company won more CNC turning work, this time from the autosport industry producing a specialised collar, as well as a contract for a family of parts for a tier one system and component supplier to the aerospace industry. So at the recent MACH 2004 exhibition at the NEC, Mick Purton placed his second order for a 13-axis M32, this time including the Cool Blaster programmable 2,000 psi high pressure coolant unit with vapour extractor.

Mick Purton explains his decision to add Cool Blaster, was to improve performance when machining, in particular, the aerospace parts made from S143, a corrosion resistant alloy steel comprising chromium, nickel, copper and molybdenum. "S143 doesn't chip at all well and causes real headaches with 'bird's nests' of swarf," he maintains.

Also key to Crown's requirements was that the 13-axis M32 machine features main and subspindles able to produce parts using three tools at the same time. This ensured that many of the complex parts it was now making were produced in a single cycle enabling the company to further improve its competitiveness, lead times and ensure high levels of consistency.

For instance, while an outside diameter is turned with a gang tool, it is possible to machine internal features from the turret. For front and back machining, the Citizen M32's 10-station turret has power-driven tools in every position and with multiple tool holders and half-indexing capabilities, enables the turret to hold up to 80 tools. As a result tools can be left 'as set' in the machine which significantly speeds changeovers and the turret can also fulfil functions other than cutting, such as part handling and automatic in-process gauging of tools as well as critical component features, if required.

The two Citizen machines now process eight different components for Crown, plus the family of 16 aerospace parts. All these parts leave the M32s ready for dispatch which also includes some very tricky features such as 45 (Degree) angle holes.

One of the aerospace parts produced in relatively small batches is a collar that supports a race of ball bearings. The manufacturing process begins by using a U-drill to hog out the bore, for finish machining. The outside diameter is then rough turned before the holes required to support the ball bearings are spotted around the circumference of the part.

The bore is then completed before a ballnose cutter is used to finish the circumferential holes to a precise depth of + 0.02 mm in order to 'seat' the bearings. The outside diameter is then finished before the part is picked-off and back-end operations performed which include further boring, threading, milling and drilling.

"Since the installation of the Citizen machines we have become really adept at programming and have managed to reduce the cycle time for this part from an initial 15 mins to just 9 mins." Reflecting he says: "Machining time using manual methods would have taken at least 50 mins. This shows how beneficial the Citizen machines are to our business."

And, he makes a big point over reliability. Both machines have chalked up an uptime of 100 per cent since installation. This is leading him to expand on the current working method and produce the original washer unmanned overnight. "We are planning to go this way for all of our components very shortly which will further improve our competitiveness," he maintains.

Mick Purton is also seriously targeting other new markets such as telecommunications and medical in order to initiate further growth and the business plan incorporates moving from the present leased premises to its own facility within two years. By then, the target is to have six sliding head machines installed.

By his own admission Mick Purton says 2000-2003 were the hardest years he has ever known in the industry, but investment has meant Crown is in a relatively comfortable position. "We have expanded our horizons by investing, built our reputation and the reward is that we are extremely busy." He concludes: "Sitting at the centre of this success are the two Citizen M32 sliding head lathes - truly in my eyes, these are jewels in the crown!"