'Specification-to-cost ratio' was the key factor used by a subcontractor to select a larger travelling column machining centre with a view to expanding its markets.

With customers that include Rolls-Royce, Westland Helicopters, Ford, McLaren and MAN B and W, Tridan Engineering of Clacton, UK, has a compelling pedigree in sub-contract precision machining. Tridan has been added to a list of only 20 approved European suppliers to MBDA in Stevenage, a global leader in the provision of missile systems to the defence industry. There are two reasons behind the growing success of this GBP 3 million turnover, 53-employee company: its belief in project management, embracing all aspects of supply including design, manufacture, assembly, treatments and delivery in line with customer requirements; and its planned programme of investment in high technology machine tools.

The latest addition to Tridan's already impressive machining capacity is a 20 tonne, 18kW Cincinnati Lamb FTV-840/3700 four-axis traveling column machining centre.

Tridan's previous capacity was 2m, so it is hoped the 3.7m provided by the FTV-840 will assist the company in its quest to open up an entirely new market.

'That is the prime reason why we bought a machine as large as the FTV-840,' stated technical sales manager Gerry Humphrey.

Selection was not straightforward however.

Tridan traveled the country looking at machines manufactured by Spanish, German and Dutch machine tool builders.

Tridan had never purchased a Cincinnati Lamb machine before but decided that the package offered by the Birmingham, UK-based company exceeded that on offer elsewhere.

'Its specification-to-cost ratio essentially won the order,' said Humphrey.

'For a large machine we were particularly impressed with how quickly it could position itself.

Also, its 12,500 rev/min spindle means it can match the capability of much smaller machining centres, so not only can we machine large components, we can also divide the bed and multi-load small parts or pendulum load different operations.

The travelling column of the FTV-840 contains all axis movements to allow in-cycle loading and so reduce load/unload times to maximise spindle utilisation.' Although only installed in March, the FTV-840 is already proving its worth.

The first job that Tridan loaded on to its new acquisition was a non-ferrous casting measuring approximately 600mm3 and it was subsequently machined 30% quicker than the company could previously achieve.

Tridan also has plenty of enthusiasm for the Cincinnati Lamb support team, describing the installation, commissioning and training process as a: 'Very pleasant experience, especially considering the size of the machine.' So straightforward has the learning curve been that Tridan is already running the FTV-840 over a double shift, equating to 20 hours a day.

At the time of visit, the machine was being pendulum loaded with aluminium castings that are part of blood analysis machines destined for the medical industry.

The parts come off complete in a cycle time of approximately 45 minutes.

Typical batch sizes are in the realm of 75-100 off.

Best of all is the news that enquiries are already starting to arrive from customers looking to make use of the machine's 3.7m bed.

One lead looks particularly strong: the customer is currently purchasing parts from Germany and is seeking a UK alternative.

'Another feature of the FTV that has impressed us is its rigidity,' continued Humphrey.

'The fixed table/moving column design is a very rigid concept and has made a real impact on the quality of our surface finish and ability to consistently hold tight tolerances.

We can also swing jobs up to 800mm between centres, which all in all makes for a very flexible machine.' The fixed table on the FTV-840 accommodates heavy loads with no detrimental effect on accuracy and eliminates table droop and roll to provide greater capacity for multiple set-ups or components measuring up to 815mm by 3700mm.

Customer drawings are usually received electronically as DXF or IGES files before toolpaths are created using an offline CADCAM package.

The finished program is checked using independent verification software before being sent via DNC link to the FTV-840.

The manufacturing schedule at Tridan is linked to a fully networked production control and management system so that the ISO 9001:2000 accredited company can fulfill customer delivery requirements.

Tridan is fully committed to offering a complete engineering outsource partnership.

'One of the reasons we are succeeding in what is a highly competitive marketplace is because we invest in the latest technology machine tools,' concluded Humphrey.