A cell capable of robotic loading of unmachined material from an Erowa 10-pallet pool to a DMG MORI machining centre, followed by automatic return of finished components, was BTL Precision's first investment specifically targeting subcontract work in the aerospace industry. Ideal for lights-out machining, the 5-axis cell was installed in March 2013 at the company's factory in Bishops Stortford.

The ISO 9001:2008-registered firm is in the process of gaining AS9100 approval for aerospace quality management and will be implementing SC21, which promotes best practice in supply chains serving the aerospace and defence industries. The latter is an established sector for BTL, accounting for around half of turnover.

Managing director and joint owner, Julian Bedford, advises that the company is already carrying out second-tier aerospace work. For example, an ongoing contract awarded mid 2013 involves the manufacture of a family of non-flight-critical, aluminium housings for a business jet. Production of 120 of each of six parts is initially required and to meet cost and quality targets, the job is done in the DMG MORI machining cell.

The 400 x 400 x 375 mm capacity machine, a DMU 40 eVo, is the subcontractor's third vertical-spindle, 5-axis machining centre from this supplier, the others being two DMU 50 eVo machines of slightly larger capacity.

An even bigger DMG MORI 3-axis DMC 1035 V ecoline with a one-metre bed is also installed, which replaced two smaller 3-axis machining centres. It produces a range of platework for a packaging equipment OEM for two to three months of the year and for the remainder of the time it often produces multiple parts clamped in modular fixtures on the table.

The first DMG MORI machine to be installed at Bishops Stortford, a 5-axis DMU 50 eVo, was acquired in 2009. At the time BTL had on the shop floor six 3-axis vertical machining centres, one fitted with a fourth axis and two with twin pallet changers.

Mr Bedford said, "As soon as the 5-axis machine arrived, our productivity dramatically improved and it was immediately apparent that this was the future for us.

"Almost all of our work requires operations on multiple faces and our 5-axis plant is used mainly for three plus two axis machining. It allows parts to be reorientated in-cycle, saving machine stoppages and component relocation.

"Six or seven ops on a 3-axis machining centre are typically compressed into two hits on a 5-axis machine and cycle times are down 30 per cent on average, shortening lead-times."

Accuracy is improved by not having to reposition workpieces repeatedly in expensive fixtures. One early job put on the machine involved holding 20 microns tolerance on gearbox bore alignment, which was much easier to do on a 5-axis machine.

The year after the DMU 50 eVo was installed, Mr Bedford and his partner, technical director Andy Moodie, attended a defence spending review seminar in London where it was emphasised that, to drive efficiency, the UK government was intent on engaging with smaller firms as well as the traditional supplier base of larger companies.

However, the speakers also made clear that production plant of the right quality had to be in place to win the work, as well as the requisite management, traceability and quality procedures. Messrs Bedford and Moodie also realised that the same prerequisites applied to gaining aerospace business, which was one of their target markets in view of the sector's long-term growth prospects.

With the lessons learnt, they started an investment programme that has seen the installation of two further machining centres from DMG MORI, which is now the preferred supplier of all prismatic metalcutting equipment to BTL. Similar brand loyalty is shown to CAM system company, Open Mind, whose hyperMILL software was purchased earlier this year, as well as to cutting tool company, Walter, and material supplier, Thames Stockholders.

Mr Bedford is keen for these associations to be seen by all parties as 'partnerships' and has even had the suppliers' logos stitched onto the machine operators' shirt sleeves.

Consistent with automatic pallet loading and long periods of unattended running, the DMU 40 eVo has 60 tools instead of the 30-position magazines on the other 5-axis machining centre. It is also equipped with high pressure, through-spindle coolant delivery to assist when cutting stainless steels and tough alloys.

The first two jobs put on the machine were both EN100 parts for the defence industry, required in batches of 100- and 200-off. Nine pallets were devoted to producing one of the components in a 50- minute cycle, while a single pallet was sufficient capacity for the second part, as the cycle time was 15 minutes.

Mr Bedford sees the ability to produce a mix of different parts as an important benefit of the 5-axis cell. It allows BTL to produce small as well as large batches economically, 24/7, and enables a rush job to be set up on one or more pallets if the need arises.

He concluded, "We are excited by introducing automation to our shop floor, as it is one of the ways British manufacturing can compete with overseas firms, particularly in Eastern Europe and the Far East.

"It is our hope that the aerospace side of our business will grow quickly and expect it to account for 50 per cent of our turnover in a few years' time."