Winning combo for high-performance aerospace projects

Tripartite collaboration between project enabler/integrator, machine tool supplier and toolholding specialist is continually pushing the boundaries of high-performance machining and increasingly reducing machining lead times and production costs for a major aerospace company.

The ongoing work between the project lead – the University of Sheffield Advanced Manufacturing Research Centre (AMRC) – and machine tool specialist Starrag UK, plus the tooling expertise of Nikken Kosakusho on a variety of aluminium and titanium aerostructure workpieces is cutting piece part costs through the creation of improved machining routines.

“Although not directly targeted by the projects, in some cases reductions in cycle times are one rewarding by-product of the work – in some cases of more than 50% compared with ‘conventional’ machining processes,” says Starrag UK’s director for sales and applications, Lee Scott.

Tom McCready, engineering and operations manager at the AMRC’s Machining Group, adds: “By setting new benchmarks in the way in which we use the full capabilities of the machine and tooling packages, we are consistently gaining new ground in the way parts are being machined. And because some of these projects involve ‘live’ production workpieces, the gains achieved at being more effective and efficient in machining are already being transferred into the manufacturing processes.”

The AMRC houses an array of state-of-the-art manufacturing equipment to enable partner companies and project sponsors to develop and trial new technologies and processes. It works closely with customers and project sponsors to select the ideal machines and manufacturing technologies required to fulfil each project’s individual demands.

Initiated by the AMRC’s Machining Group with two of its Tier 2 partners – Starrag UK and tooling integrator, Nikken – Starrag’s Heckert X40 horizontal machining centre has been moved a few hundred yards from its initial AMRC Factory of the Future base on Sheffield’s Advanced Manufacturing Park to Nikken’s Innovation Centre, Europe. Engineers from the AMRC team are continually working with Nikken and Starrag to utilise the impressive capabilities of the five-axis machine and its tooling packages.

The Heckert X40’s high-performance features include impressive rigidity and damping, based on established and renowned build principles, complemented by rapid traverse rates of 80 m/min and a 20,000 revs/min spindle that offers torque values up to 350 Nm.

Among Nikken’s world-class toolholding solutions is the Slim Chuck, a high-accuracy collet chuck that boasts minimal runout – three microns at four times diameter – leading to higher component precision and improved tool life. Also, its maximum gripping torque of more than double that of traditional ER alternatives not only complements the Heckert X40’s rigidity/stability to permit more aggressive machining parameters but also improves process security and therefore leads to reduced scrap.

The workpieces – of titanium and aluminium – all fit within the machining envelope of 700 mm by 750 mm by 750 mm (X, Y and Z axes).

Adds Mr McCready: “With all three partners collaborating closely, we have so far collectively achieved some incredibly successful results by pushing the limits of the machine and the tooling for increased metal removal, without jeopardising quality, on these workpieces.

“Importantly, we closely monitor and record the resulting performance data in real time relative to NC code line via digital enabling/connectivity through a Siemens Edge device – the machine incorporates Starrag’s human-machine interface (HMI) for easier, intuitive programming and operation – including factors like machining forces and spindle temperatures.

“We interpret this data and, if necessary, adjust the processes to suit and ultimately arrive at an improved NC code to achieve consistently repeatable process improvements by setting new machining benchmarks.”

Starrag’s Lee Scott, comments: “This is another example of the success of Starrag’s long-term relationship with AMRC and Nikken, and in this case it highlights how an affordable machine – one that combines all the best attributes of its predecessors but in a compact footprint and at a cost-effective price – can produce real time savings and cost benefits on a variety of workpieces for companies of every size.”

Nikken’s deputy managing director, Nathan Ray, adds: “Time and again these projects are providing lessons in the rewards of marrying a high-performance machine with world-class tooling, with the set-up being operated by forward-thinking engineers to fulfil the true potential of ‘no compromise’ machining.”

Since 2003 Starrag has progressively installed eight machines at the AMRC and at sister centre, the Nuclear AMRC, as part of its AMRC membership.