CHIRON SPEED AND ACCURACY SAYS IT ALL FOR BOWD PRECISION ENGINEERS
Bowd Precision Engineers in St Ives, Cambs, has supplied the cellular communications industry with precision high quality components for almost 30 years. The last four years has seen an explosion in this market and, for Bowd, the key to meeting that demand has been its investment in Chiron vertical machining centres.
Supplied by Chiron Werke UK, the 10 VMCs are operated around the clock to give the company “a significant competitive edge” in terms of both delivery and cost, and they have enabled the company to grow to 40 plus employees and to achieve a turnover in excess of £2 million – a substantial increase over the £1.4 million achieved last year.
While founded to produce turned parts for the medical industry, prismatic machining is the biggest activity at Bowd today - though turning still represents an important part of the business, serving particularly hydraulic component OEMs.
This followed the early identification of a potential market for milled components in the then fledgling cellular communications industry. And as that industry has grown so has Bowd, with partner Dick Pauley being primarily responsible for developing the milling sub-contract side of the business.
It started in a small single-shop unit then moved into a larger unit on St Ives’ East Street, and has since expanded with the addition of two further units on the same site. The addition of the third unit, at the end of 1999, effectively increased the workshop area by an additional 25 per cent.
Because Bowd became involved early with the cellular communications market, it has developed an unrivalled depth of expertise in machining the complex parts required and, as a result, has established an enviable reputation at home and abroad. It now has customers in Scandinavia as well as in the main centres of mobile communications manufacture in the UK. At the same time, its hydraulic components turning business has also extended beyond these shores with customers in Germany and the Czech Republic.
Machining of parts for cellular communication products calls for accuracy and flexibility due to their precision and complexity. It was in search of such a specification that influenced Bowd to purchase its first two Chiron FZ12W machining centres in 1996. Since then further Chirons have been added and now the St Ives company has a total of ten; eight FZ12W Magnums and two of the smaller FZ08Ws.
Featuring X, Y and Z axes travels of 550 mm by 300 mm by 425 mm, the Chiron FZ12W Magnum boasts a fast tool change time - 0.9 sec with chip-to-chip achieved within 2.4 sec - and spindle speeds up to 20,000 revs/min from the 45 kW motor. There is an option for a turbo spindle rated at an amazing 60,000 revs/min. The machine is capable of milling at 250 cm3/min, drilling 36 mm diameter and M24 tapping.
The Chiron FZ08W has X, Y and Z axes travels of 300 mm by 250 mm by 250 mm, and features a 0.5 sec tool change with chip-to-chip in 1.5 secs. Spindle speed is up to 27,000 revs/min (optional) and the machine is capable of drilling 16 mm diameter, tapping to M12, rigid tapping at 6,000 revs/min and milling to 200 mm3/min.
Partner Denise Brown, who has been involved with the company virtually since it started, says: “The Chirons suit our type of work very well. They are fast (traverse rates are up to 60 m/min), accurate and very compact (a 1 m by 2.4 m footprint for the FZ08W), which is important to us given the limited space at our disposal. They are also extremely versatile and we use them to machine widely varying batch sizes as small as 20 or even lower, or as large as our customers need.
“Lead times can be short, sometimes with as little as a week’s notice, so the Chirons’ ease of set-up combined with our in-house programming capabilities are important.”
The Chiron features admired by Bowd include the very short tool change times - which at 1.5 secs chip-to-chip on the FZ08W is the industry leader - and the indexing table that maximises machine utilisation. The four latest purchases also feature multi-jig fixtures to further improve productivity. And to extract the maximum benefit from the machines, Bowd works them 24 hours per day, seven days per week to maintain its “significant competitive advantage” in terms of both cost and delivery.
The vast majority of the work on the Chiron machines is machining components for the cellular communications industry, including waveguide parts for cell base stations as well as “small bits and pieces” that go into mobile hand sets.
The waveguide components are often complex with a wide variety of machined features – milled profiles and flats, intricate recesses and multiple holes. These are readily machined on the Chirons aided by their accuracy, fine control and 12-station tool magazines. Also, maximum use is made of the machines’ up to 20,000 revs/min spindle speed when machining aluminium.
Chief Inspector, Steve Crouch says: “We often machine parts to tolerances of 25 microns but can go tighter if required. Also, waveguide parts are demanding in finish and flatness - particularly on some of the internal faces that are vital to transmission of the microwaves - and the Chirons are well capable of meeting these stringent specifications. We also rely on the geometry of the machines for accurate face-to-face referencing during multiple setting.”
Programming is all done in-house and to ensure the Chirons are kept in continual production, one programmer plus an assistant is occupied during both the day and night shifts. All the CNC machines have DNC links and the host is networked to Bowd’s CAD/CAM system, which is used for programming the complex waveguide components.
Bowd also recognises the importance of maintenance to keep its machines operating, and of the cost of that maintenance. For this reason, it has taken out five-year warranties on its four latest purchases and has annual preventative maintenance contracts on the others.
Comments Denise Brown: “Having the extended warranties not only ensures the machines are kept working (Chiron Werke UK operates a maximum four-hour response time), it also means we know exactly what are our maintenance outgoings. Chiron Werke UK is a very caring supplier and always responds promptly to any call-out request we make”.