Looking ahead
Ability to exploit investment in Citizen M32 CNC sliding head lathes creates opportunities for future growth at Rowan Precision.
Having had the foresight to invest in its production capability for small turn-mill part production by introducing an assembly service, Rowan Precision has created a new raft of opportunities for its precision machining operations. This is especially significant in providing components for the bespoke lighting, medical, electronic, aerospace and defence sectors.
Indeed, lighting components machined on the company’s Citizen M32 CNC sliding head lathes then finish assembled with bought-in items such as lenses, cables and pressings at the Witton (Birmingham) machine shop have recently been installed on Roman Abramovichs' latest addition to his personal fleet of five luxury yachts. Martin Barker, joint MD of Rowan Precision elaborates: 'The ability to accurately machine components, source bought-out items and produce finish assemblies is enabling the company to evolve from being a turned parts supplier to one that is an important extension to the businesses of our customers. Importantly to them has been our design for manufacture input, the availability of the flexibility of our machines for prototype and sample components, and our CAD facility that provides finished drawings once development parts are acceptable.'
He is very keen to attribute the fast setting and high levels of flexibility of the Citizen M32 as a true machining centre, of which three of the four machines were installed during 2008: 'They not only provide us with very consistent production on both batch and longer production runs, but can also be used for component development and effectively producing just a few sample parts for customers.'
Rowan Precision’s expertise has grown from its ability to machine a spectrum of exotic and very difficult materials such as palladium, iridium, titanium, platinum, gold, nickel, sliver, high alloy and stainless steels, plus aluminium, copper, bronze, plastics and even Tufnol. Barker, who recounts an unusual experience and advantage of the Citizen design: 'With a library record of materials such as these it is clear why we were influenced to install Citizen machines due to their total flexibility to perfect machining cycles. Quite often we have to reclaim swarf because we have to provide full traceability and material records. Here, the ergonomics of the Citizen M32 means they are easy to clean for recovery of precious metals when the job is completed.'
He also points to the changing world of production where long running contracts of some 80,000 parts a year have dropped to 250 and 500 batches that are now required almost by return. In these instances, the speed of setting and prove-out, aided by the number of standard tools that can be carried on each machine means that utilisation is very high. In his view, the machines are certainly proving to be customer-friendly for his operation. As a matter of course, two of the four Citizen M32s have standard tool sets and while off-line programming is available on the shopfloor, the setters generally prefer to program at the machine control while jobs are running.
Barker and joint MD Chris Kent started the company in 1984 with just a desk and 'phone apiece to provide a component sourcing, inspection and delivery service to customers in the Midlands. So successful was the service that it spurred the decision to go into production that led to the purchase of six cam autos. Again success followed, and the company outgrew its premises in just three years. This forced a move to the current site, a new build to Rowan’s requirements on Poplars Industrial Estate where it took over two units of around 10,000 ft2. A third bay was then added and the cam machines were gradually phased out in favour of CNC sliding head technology. In 2003, as a reaction to steadily increasing levels of component complexity, shrinking batch sizes and shorter deliveries, the first Citizen M32 was installed.
Says Barker: 'This machine was a culture change to the business not only due to the way it performed, but also because of the overall package from NC Engineering (now Citizen Machinery UK) of service support and help when needed on applications. Such were the levels of consistency in production that quality issues faded away and we were suddenly much more competitive and the added flexibility was giving us far greater opportunities with customers.'
Between 2006 and 2008 the company had grown by up to 15% a year and it now employs 14 people. Over £1 million was spent last year on the three additional M32-V Citizens plus two Kestrel and Hawk non-contact measuring machines capable of automating SPC data output. A crib-style vending machine was also installed creating a tremendous reduction in downtime in support of the turn-milling operations and providing the capability to meet 'cost-down' targets and enable accurate forward planning and bringing tool buying under control.
Core shift working is between 6am and 6pm which is followed with the Citizens being run under limited manned operations through the night when the bars are replenished in the magazines and over checking performed on any key dimensions. He says that over the 12 months he has found that 'the Citizens are so stable and production almost a routine because offset correction is rarely used, so consistency through a batch is very high which customers like. We have also found it helps when we assemble components.’ He also explains how work is a very mixed bag of complexity and difficulty to machine materials with cycle times varying between 1min and 15mins depending on number of features. Stricter tolerances tend to be between 15 and 20microns and typical surface finishes of 0.8microns CLA are easily maintained.'
The three latest 13-axis Citizen M32 installations are each fitted with Citizen Machinery’s CoolBlaster III 2,000 high pressure coolant system described by him as a valuable asset especially on some difficult materials where positive swarf control is always maintained and overall machining becomes predictable along with tool life. The Citizen M32-V has the added flexibility of two Y-axis crossfeeds to the 10 station turret and gang tool slide which enables up to three tools to be engaged simultaneously in a component. The machine is able to carry up to 72 tools using special holders, has a 7.5kW, 8,000revs/min main and 3.7kW, 7,000revs/min subspindle.
Barker describes a 316 stainless steel medical industry component that is currently running in a single operational cycle time of 13mins. The part is just 7mm diameter by 24mm long requiring a considerable amount of the OD to be milled away. It is initially spot drilled and drilled through at 4.8mm diameter with a 2mm wide longitudinal keyway milled in the OD that breaks into the bore. There is a further spot and cross-drilled hole 2mm diameter and another long keyway form, 1.65mm wide, that has to be milled into the OD.
Transferred to the subspindle, a very complex milled profile using a 2.5mm dia endmill removes a quadrant of the OD over two-thirds of its length before the spindle is indexed 180o and the operation is repeated on the adjacent quadrant to match and line up with the first profile. When completed, almost three-quarters of material is removed completely from the wall of the component at one end and half the material in the centre.
Now, with a highly productive production operation in place, the two directors are looking to Europe for expansion aided by the current value of sterling. The website is already multi-lingual for French, German and Italian customers, and an agent has just been appointed in Germany. Martin Barker concludes: 'We are now reaping the benefit of our investments because we are in a very strong position to take maximum advantage of any opportunities that arise in the market.'
