Suppliers design system solutions

End users demand more from their suppliers these days, both in terms of quality but also in terms in capability. That includes leaning on them for the design and procurement of entire systems. It has become the norm, particularly in specialist areas. With firms keen to concentrate on core competencies, much of the system level engineering design work is outsourced and is now the responsibility of the supplier. But, that has meant suppliers have almost universally had to bolster their own in-house design expertise to keep up with the trend and deliver customers solutions to their problems. HepcoMotion, a linear motion technology specialist based in Devon both designs and manufactures its products. Since its inception in 1969, the company has slowly evolved from being simply a component supplier of linear motion mechanisms, to offering customers full and complete solutions. "We have seen a massive shift," says Ray Hall, managing director of HepcoMotion. "When we were a fairly young company we were selling dozens of components to hundreds of companies that had design expertise in house and they wanted to build all these machines and systems themselves. But now we are predominantly supplying complete systems." The company supplies a broad range of industries for a host of varying and often fairly niche applications. As a result, it has had to engineer its products that, although standard, provide a great deal of flexibility in terms of performance and can be built in a modular fashion. As a result, its standard products meet around 95% of the projects the company undertakes. Technical director at the company Peter Fanshawe has overseen much of the product design and says: "We have tried to design a general purpose product and inevitably have been guided by the track record of applications we have seen over the years." The experience the company has built up has seen it broaden its product range making it more than likely able to solve most problems. "If you look at the sealed belt drive," says Fanshawe. "It is something built on experience with previous similar products. It comes from the driven linear system but it addresses slightly different areas, applications in cleanroom environment. And other newer products have been optimised for load capacity and stiffness which have been deemed to be very important." The trend has also been driven by the need to optimise the design process. The 'one stop shop' approach of getting experts in a specific area, be it linear motion, sensors or bearings, has proved to be much more economic than employing generalist engineers that will throw their hands to anything. Getting experts is not only quicker and usually proves to be a much more optimal solution, but also is a means of minimising risk. The use of modular components that can be assembled in varying ways has allowed the company to take on some pretty interesting projects. The Hamilton Kerr Institute, a department of the Fitzwilliam Museum at the University of Cambridge, recently came to the company as they needed a system to digitally scan art portraits. The department were going to use a ultra high resolution camera to capture the paintings in visible spectra, infra-red and UV to both store the pictures digitally and hopefully reveal fascinating never before features from the original masterpiece. Stuart Hill, an application engineer at HepcoMotion, says: "In conjunction with our drives partner Smart Drives, we provided a turnkey system that consisted of two horizontal drive units, two vertical drive units and on top that they would mount their camera. This was all mounted on a framework which also has another one of our ancillary products, ZIMM, a screw system. This basically allows the whole frame to tilt as some pictures couldn't be stood upright and they needed to be scanned perpendicular to the surface." Hampshire based LG Motion also designs and manufactures its own linear motion systems and regularly takes a consultative approach with its customers. Gary Livingstone, managing director of LG Motion says: "A lot of the big firms have got rid of their engineering departments and therefore need somebody to solve these problems. This allows companies to concentrate on the things they are good at, and we will concentrate on what we are best at. And ultimately, that should mean the project gets recognised far quicker. "We make use of modular standard products, the clever bit is the know how of putting it all together." The two biggest drivers for the company are cost and delivery time. The company has strong ties with the scientific and research community and, it has recently completed some work Diamond Light Source, the UK's national synchrotron science facility. It designed and supplied a large custom built X-Z detector positioning system and the design specification called for the ability to load the positioning rig with multiple detectors up to 280kg mass with a volume of around 1m3 over a 1.55m horizontal and 0.85m vertical travel range to allow increased flexibility and research throughput. At acceptance testing, the system was actually loaded with 420 kg and positioning repeatability for both axes was measured to better than 10µm. Design process Certain applications will dictate which technology to use. For example, a lead screw isn't the most efficient drive method but it is ideal for fine low speed, smooth manual adjustments, and has very smooth motion at low speeds. It is also very good for vertical applications as the load will not drop if the power is removed. However, ballscrews should not be used for improving throughput. "When it comes to a particular environment, there is no one solution," says Livingstone. "There are many variables that need to be considered. It is knowing what you need the system to do and taking many factors in to your system solution." Firstly, engineers must understand in relatively simple terms what they are trying to do. What is the payload, the stroke length, the required acceleration forces, the offset loads, the duty cycle, how many hours per day it will run, the required life of the system, the space envelope of the system and critically what is the environment it will operate within? There are lots of techniques which come down to cost, application and available space. "Some of the slides can run without lubrication so that makes them ideal for cleanroom environments," says Livingstone. "But, you can also get low particle emission rails and carriages and ballscrews as well. Sometimes you can positively pressurise a system if you have a way to cover it and keep dust from getting in. Many companies will also supply linear rails that have a special coating which can make them capable of operating in a wet, dusty or dirty environment, useable outside." The complete nature of these variables and usual lack of experience from in house engineering teams means that it is advisable to call on the experts which deal with these problems on a daily basis. This then insures an optimal design, minimal risk and often can be provided from a single source. It is worth noting this will likely result in higher purchasing cost than buying the components, but delivery time and through life costs are normally more favourable.