The switch from producing components in separate set-ups on two-axis lathes, milling machines and machining centres to achieving one-hit production on a pair of fixed-head turn-mill centres has enabled Precise Component Manufacture Ltd (PCML) to be considerably more competitive in the production of complex multi-feature parts.
The turn-mill centres — Miyano BNA-42 DHYs supplied by Bushey-based Citizen Machinery UK Ltd
(www.citizenmachinery.co.uk) — are also allowing PCML to be flexible in terms of its machine operators, as it no longer needs to apply the ‘one machine, one operator’ way of working; they have also reduced overall lead times, with cycle time reductions of some 20% compared with two-spindle single-turret machines.
Furthermore, the Miyanos are playing a key role in PCML’s award-winning Procure-Smart service, which sees some 60% of customers able to reduce stock holding while being guaranteed part availability ‘on demand’. PCML director Kevin Miller says: “Our customers are forever demanding more-complex machined components to be held to ever-tighter tolerances. These are both prismatic parts and shaft-type workpieces that require a sequence of turning, milling and drilling operations, so moving from a combination of CNC turning- and machining-centre work towards single-set-up operations on our first Miyano was an essential progression.
“With the money spent on each Miyano, we could have bought two standard CNC two-axis lathes and a compact machining centre, but if we had gone down that route, we would have needed three operators and our overheads would have been higher. Today, each Miyano only needs what is, in effect, ‘half’ an operator, because once the machine is set up and running, the operator can be confident that it will consistently carry out its tasks.”
Partnership working
Even when machining components just 5mm long and 5mm in diameter, the Miyanos allow PCML to cost-effectively meet the demand for the supply of increasingly complex components — often in batches as small as 20. These are supplied to customers in industry sectors that include the life sciences, ink-jet printing, medical, semiconductor, analytic equipment and high-technology welding. The company also has customers that are involved in laser-based manufacturing.
“We have established working partnerships with the R&D teams of many customers, allowing us to collaborate with them on developing both components and future products,” says Mr Miller. “Our manufacturing expertise also includes rapid prototyping and assembly, and it often results in us machining very-high-specification workpieces — usually in quite low volumes.
“While we have steadily invested in five-axis machining centres for increasingly complex prismatic work, our new Miyanos have allowed us to really ‘up the ante’ in terms of our multi-feature, predominantly turned parts from bar up to 42mm in diameter. Even on the small-batch work that characterises our business, the overlapped and simultaneous machining cycles provided by the machines’ twin spindles and twin turrets allow us to be ultra-effective in the supply of a wide range of parts in varying material types.”
The Miyano BNA-42 DHY is a compact, fixed-head turning centre that combines a 42mm bar capacity with a secondary spindle, a Y-axis main turret and an independent sub-turret. Citizen says it is the flexibility offered by being able to apply 16 tools (eight driven) on the main turret, with 35mm of Y-axis cross-feed — along with the availability of the six-station sub-turret adjacent to the main spindle for back working — that allows high levels of productivity to be achieved. The main and secondary spindles are rated at 7.5 and 5.5kW respectively, and both have a maximum speed of 5,000rev/min. The main turret’s eight driven positions are powered by a 2.8kW 5,000rev/min motor; the station-
to-station index time is 0.2sec.
First UK installation
Mr Miller bought the first Miyano after seeing a video of the machine at Citizen Machinery UK’s headquarters. “We were the first UK company to install a BNA-42 DHY, and its immediate success prompted the installation of a second, similar machine within a few months.
“Introducing seven-axis turn-mill technology did not faze us. Using software developed in-house, we simply tweaked the existing machining programs for our two-axis turning and milling, then used the same standard tooling to produce in a single set-up a whole range of components that we previously turned and then transferred to a machining centre for further operations.”
PCML was started in 2000 with three full-time employees, one part-time worker and four manual machines. Today, the ISO 9001:2000 accredited operation has a multi-million-pound turnover, 56 employees (including five apprentices) and more than 30 machine tools.
In conclusion, Mr Miller says: “Everything we invest in is designed to maximise cost reductions, minimise lead times and reinforce the partnership approach we have with our customers. Our programme of continual improvement is driven by the need to be ultra-competitive on small-batch complex machining. UK companies can not compete with the labour rates overseas, so we have to combine our high skill levels with best-in-class machining technology to stay one step ahead.”