Product category:
Horizontal machining centres (HMC)
News Release from: StarragHeckert UK | Subject: StarragHeckert ZT 1000 machining centre
Edited by the Manufacturingtalk Editorial
Team on 16 December 2004
Machining 'exotics' - research cuts time
cycles
Dedicated to push out the boundaries of all aspects of machining difficult and exotic materials, A UK university is already showing how machining times can be reduced.
Dedicated to push out the boundaries of all aspects of machining difficult and exotic materials used in aerospace, airframe structures, turbine, power generation, medical, F1 and certain areas of the automotive sector, using a GBP 1.1 million StarragHeckert ZT 1000 head changing horizontal machining centre, the University of Sheffield's new Advanced Manufacturing Research Centre (AMRC) is now setting out its capability at its new facility With the equipment and support services that have been installed, it will enable the AMRC to define how far production process technology can economically advance in metal cutting
This article was originally published on Manufacturingtalk on 9 Dec 2002 at 8.00am (UK)
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According to Dr Rab Scott, project manager: "It has taken us five years to bring this global research centre together but as a result, we have benefited from the care in establishing the right equipment and facilities with key collaborating partners.
This will enable UK manufacturing to have a better understanding of metal cutting, be more effective and hence competitive, particularly in the aerospace but also in related sectors of industry." Dr Scott follows on to say: "With the equipment we have installed and support of strategic partners we are able to push out the boundaries of machining processes that industry cannot or would never be prepared to chase.
Although it is not the objective, we can even break things to determine the limits of acceptance." He cites the machining of a pair of wing flap ribs in 10 hours rather than the normal 36.
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The AMRC is targeting to reduce the time further to six hours with a 50 per cent reduction in the number of cutting tools used.
When it is considered there are 50 flaps on each wing of the aircraft, the cost savings begin to repay the research effort, even without the spin-off of any transfer of technology.
To help in machining investigation, modelling by simulation of metal cutting, investigation of thermal changes, chip formation, residual stresses, tool wear, effects of coolant will run concurrently with actual metal cutting processes bringing what Dr Scott describes as: "Changing the physical into a virtual world of research without actually having to make and test everything." As part of the initial investment of GBP 20 million generated from industrial contributions and DTI support, this high technology hub has just installed a GBP 1.1 million, 37 tonne StarragHeckert ZT 1000 head changing horizontal machining centre.
Funding of generic projects of interest to all partners are drawn from central coffers with AMRC taking ownership of the intellectual rites that the centre can use to generate revenue in the future.
However, specific projects will be partner funded and projects involving several partners co-funded and already there are currently some 40 projects underway.
Behind the concept of AMRC is the quest by the world's aerospace companies to cut weight and develop higher performing, more economical aircraft by maximising the benefits gained from using high performance materials.
The downsides are that materials such as titanium and heat resistant super alloys and modern composites are very difficult to machine so the trade-off between material advantage against cost to produce, has never before been such a key issue.
The problem is not to simply cut faster or develop new tooling solutions to run at optimised metal removal rates.
Processes have to be realisable, reliable and most important, repeatable.
As ever, the daunting factors to be taken into the equation are cost-effectiveness plus any detrimental effect any high performance production process has on the part, the structure of the material, internal stresses and ultimate fatigue have to be considered.
The AMRC is next to Sheffield Airport on a 40 hectare Advanced Manufacturing Park owned by UK Coal.
Previously an open cast mining area, the park was concepted to create some 4,500 jobs by 2007 from a cluster of high technology companies.
The growing list of collaborating companies is described by Dr Scott as: "A critical resource of expertise and having considerable practical experience." He also describes it as demonstrating the serious nature of the projects and potential high returns that could be accrued for manufacturing.
These currently include CADCAM software for 3D model creation, analysis and up to five-axis machine programming.
StarragHeckert of Switzerland, one of the world leaders in multi-axis machining of difficult materials is also sharing its R and D engineering and technical knowledge and sending graduate engineers to the UK to be closely involved with project work.
Sandvik and Technicut have supplied highly critical advanced tooling and are working with StarragHeckert on high speed machining strategies for blisks as well as hard metal cutting techniques.
These projects are not only backed by Boeing but aerospace specialists and suppliers in the UK such as Messier-Dowty, Callender Aeroport, Hamble Structures and Reliance Gear Company.
In addition, a specialist Microscopy laboratory with key equipment supplied by a non-destructive testing specialist is also supported with access to the University of Sheffield?s advanced on- site facilities such as electron microscopes.
The StarragHeckert ZT 1000 is the largest acquisition and a prime example of how the AMRC has identified the importance of equipment to provide the criteria for not only eliminating as many variables as possible before its research starts, but providing the capability from using advanced machine tool technology to ensure credible results.
The twin-pallet machine will accept parts weighing up to six tonnes, has two exchangeable heads, weighing one tonne each, which sit on their own pallet for automatic exchange.
One head is a gear driven 37kW spindle giving 6,000 rev/min but able to develop a massive 940Nm of torque enabling deep aggressive roughing and the other, a 24,000 rev/min, 40kW spindle with 43Nm of torque for high speed machining sequences.
According to Dr Scott, much of the research and development will be focusing on the optimisation of cutting conditions for a certain material without degrading the quality of the part or the material.
He described how the machine, component and material all have natural frequencies which lead to different levels of vibration under cutting conditions.
One of the targets of AMRC is to optimise the process then take any vibration created beyond the current limiting frequencies by dampening out the dominant vibration elements, similar to driving though a wheel balance problem at certain speeds in a car.
Once achieved, and this is where the comment about breaking things is relevant, it enables the rates of metal removal to be enhanced considerably.
Dr Scott talked of increasing the cutting rates for titanium by an unbelievable factor of 10.
"We are already reducing cutting times by a third," he said, "But of critical importance is that we do not set up stress, potential defects within the internal structure of the material that influences behavioural fatigue.
And this is where our material testing capability runs hand in glove with machining optimisation." Longterm benefits however, are not just faster removal of metal.
To simplify aerospace assembly for instance and stock control, larger monolithic parts with bigger surfaces and thinner wall sections will need to be machined effectively, hence the size, capability and precision of the StarragHeckert ZT 1000.
And, turning this on its head, Dr Scott maintains: "Research will also significantly influence the future design of components and even the machine tools and production concepts that are needed to make them.
You will never make the omelette without first breaking a few eggs and that is what we are going to be doing with the security of being away from the production environment.".
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