Download the White paper Composites in Machine Structures
Mention composite materials to most engineers and they’ll probably think of advanced aerospace structures or parts for Formula One cars. Yet, these versatile materials are gradually finding their way into all manner of industrial applications. Not least, into areas where more traditional materials, such as steel and aluminium, have traditionally been the materials of choice.
Until now, the use of composite materials outside of the light weighting applications, such as mentioned above, has generally been limited to specialised machine and automation systems. This is partly due to their cost, as composites can be more expensive than steel or aluminium. More frequently however it’s because design and manufacturing engineers have yet to grasp the real advantages that composite materials bring when designing or constructing a much wider range of machine systems.
Physical and mechanical advantages
Composite beam structures used in automation or materials handling systems, for example, offer significant physical and mechanical advantages over their steel or aluminium counterparts. Composite structures are lighter, stiffer and can be constructed to offer superior levels of damping, enabling machine systems to be operated at far higher speeds and with much greater accuracy and repeatability.
Machine tool manufacturers are under pressure to improve capacity, quality and throughput. They are now finding that carbon fibre reinforced composite components can be engineered to deliver twice the stiffness of steel at a quarter of its mass, while providing vibration damping properties are twenty times better than steel and, significantly, zero thermal expansion in any given axis.
When comparing the costs of steel or aluminium with composite parts, it is important to embrace the wider picture.
Firstly, modern composite manufacturing techniques produce accurate components with little requirement for post processing operations. This significantly narrows the cost gap by reducing the time taken for a part to be prepared for installation on a machine.
Secondly, reducing the weight of large moving components allows designers to select smaller bearings, motors and other motion components. Once a machine goes into service, the reduction in energy costs provided by this weight reduction can pay back any additional material costs well within the lifetime of a machine.
Eagle doubles laser cutter accuracy
The benefits of composite structures can be demonstrated by a recent project carried out by us for the fibre laser machine manufacturer, Eagle. They sought to reduce weight and deflection in a 3.1m long Y-axis transverse beam used in one of its laser cutter models. The existing steel part was replaced with a thin-walled foam core reinforced composite design, which enabled the weight of the beam to be reduced by as much as 44%, while increasing its stiffness.
Eagle was able to take advantage of these improvements to double the peak acceleration of the beam from 3g to 6g which, in turn, reduced the time required to cut a sheet of material by up to 30%. Furthermore, the extra stiffness and improved damping characteristics of the part resulted in accuracy improvements of up to 50%.
To find out how CompoTech can help you with your next project, contact us now.