Expertise and investment fuel Manthorpe’s continued success

Citation

(2009), "Expertise and investment fuel Manthorpe’s continued success", Aircraft Engineering and Aerospace Technology, Vol. 81 No. 2. https://doi.org/10.1108/aeat.2009.12781bab.001

Expertise and investment fuel Manthorpe’s continued success

Article Type: Aerospace technology From: Aircraft Engineering and Aerospace Technology: An International Journal, Volume 81, Issue 2

Precision aerospace machinists Manthorpe Engineering is to install a £1 million, three-machine production cell with 24-pallet robotic machine loading to produce a range of complex aluminium, steel and titanium bearing housings. The flexible cell, engineered as a turnkey package by DMG (UK), will provide automated production of ten types of housings in on-demand sequence for a new generation of aircraft engines due to go into production in 2011.

The system is built around two of the latest Deckel Maho DMU 70 eVo linear, five-axis machining centres and a Gildemeister CTX 520 linear multi-axis, turn-mill centre. The machines, set up and inspection stations and pallet storage will be serviced by an Erowa ERS five-axis robot with 24 pallets each 600 mm², that run on linear rails between the machines for loading and unloading against fully automated production planning and scheduling instructions.

Once installed, the cell will represent a complete “production reversal” for the company, extending it from its “niche” machining business of producing ultra-complex, high-value aerospace and power generation parts in very difficult to machine materials up to 3 m in diameter into larger quantities of smaller but still high-value components.

Indeed, the company’s investment philosophy has seen some £6 million injected over the last three years in new machine tools and equipment. It has also spent £1.25 million in a new 20,000 ft² machine shop that is some 11.5 m high and has purchased an additional six acres of adjacent land to add to its 13 acre site in Ripley, Derbyshire, UK.

The company, according to engineering sales director Chris Bowley, is now planning more diversification by taking its technical knowledge, skills and capability into expanding its power generation operations and supporting renewable energy sectors, as well as nuclear engineering. It also plans to provide the same level of service that has been built up on the back of its mushrooming aerospace expertise involving small to medium batch production of complex components.

At anytime in the machine shop, materials as diverse as aluminium and stainless steel as well as exotic alloys including Nimonics, Inconel, Waspalloy, Hastelloy and titanium can be found. Enter the production hall and the type of components machined truly reflect the whole attitude of the business and the high investment by the £30 million turnover privately owned group that employs 220 people.

The buildings are impressive, the machines are new and, the skill level very apparent as Chris outlines: “We are a service provider. We have no own product and we build the company on the back of the image of the business and what it is able to achieve hi supporting the customer base.”

He maintains: “To operate in this sector you need a workforce that is quality driven and to endear this message, everything we do has to reflect this train of thought.”

Manthorpe Engineering has progressively developed its strategy from its formation in 1978 mainly supplying Rolls-Royce in the production of rings and casings up to 3 m in diameter, and many of these components have up to 500 or so features to machine to very stringent geometric positions. Said Chris: “It’s very much a niche area for producing such large complex and expensive parts from forgings that can cost tens of thousands of pounds.” He then follows on to explain the need to meet “cost-down” demands, as another reason for such heavy investment in new technology.

As a result of the equipment installed and the development of five-sided machining strategies, often the number of operations on a component has been halved and, over periods of time, some cycle times have been able to be significantly reduced by up to 70 per cent.

Sitting prominently on the shopfloor is a five-axis Deckel Maho gantry design machining centre with vertical cross beams. This DMG (UK) of Luton supplied DMU 340 FD is worth over £1.3 million and is able to combine milling with turning operations on parts having a diameter of 3.3 m and weighing up to 7 tonnes. The machining envelope is a massive 2.8 × 3.4 × 1.6 m to which its SK50 taper spindle can be positioned at a rapid traverse rate of 60 m/min in X, 30 m/min in Y and 40 m/min in Z. The 44 kW power-spindle, specified as a 5X torqueMASTER, is capable of 10,000 rpm and develops up to 1,550 mm of torque through its NC-controlled B-axis swivelling head. Tool capacity is 120 tools and the 2.5 m pallet can be rotated at up to 120 rpm for the combination of turning cycles with multi-axis milling and drilling.

Set beside the DMU 340FD are two further DMG (UK) supplied five-axis machines, a DMU 160 FD and DMC 125 FD. The DMU 160 FD has a 1.6 × 1.25 × 1 m working envelope and 1.5 m diameter 250 rpm rotary table. This 44 kW spindle machine was primarily installed to produce 200 engine turbine casings a year, replacing a two machine process involving a vertical turning lathe and machining centre. The pallet exchange is also important for Manthorpe by reducing lost time to load and unload completed parts while machining continues.

Meanwhile, the smaller DMC 125 FD, which still has a large 1.25 × 1×1 m working envelope and 1.25 m diameter rotary table that is capable of 500 rpm is currently being operated by one of Manthorpe’s 19 apprentices in his final year. This is a typical factor that demonstrates the level of training being provided by the company to ensure future profitability.

Owing to the high complexity and to take maximum advantage of appreciating the relationship of the features for geometric position, access by tooling and fouling points for fixturing, Manthorpe has also installed a rapid prototyping machine that is fully integrated into its Unigraphics NX-5 CAD to CAM system.

Explained Chris: “While solid modelling on the screen and the machine tool controls are first class and well supported by programming and setting, you cannot better actually taking hold of a complex part and gaining the “feel”. As parts have got bigger and more complicated, details can be hidden from view and this way of working makes our initial appreciation and setting of machines so much easier,” he said.

As a run up to the installation of the new cell, DMG (UK) has also loaned Manthorpe one of its latest DMU 70 eVo linear, five-axis machines in order that programs and tooling can developed. Although Manthorpe has a “preferred” customer relationship with DMG, two other suppliers of high-quality machine tools were considered for the turnkey project. Factors such as experience of previous installations, the continuous high standard of after-sales support and the overall solution put forward helped to win the day.

The DMU 70 eVo linear machines have axis travels of 750 × 600 × 520 mm, 35 kW 18,000 rpm spindles delivering 130 Nm of torque. Acceleration in each axis is 10 m/s² to a rapid traverse rate of 80 m/min in X and 50 m/min in Y- and Z-axes using linear drive technology. The NC swivel rotary table is capable of machining angles up to 18° and will rotate at up to 40 rpm in the B-axis and 50 rpm in C.

The Gildemeister CTX 520 linear turn-mill centre with counter spindle and 12 driven tools also has linear drives giving 60 m/min rapid traverse in X, 15 in Y and 45 in Z. Spindle power is 45 kW with 750 Nm of torque and speeds up to 4,000 rpm. The Y-axis is +40 mm.

Details available from: DMG (UK) Ltd, Tel.: +44 (0)1582 570661, web site: www.gildemeister.com

Manthorpe Engineering, web site: www.manthorpe.co.uk