Bosch Rexroth’s ‘Big Bang’ automation strategy, launched back in February last year, wasn’t just presented as a new way of working but as a way for machine builders to reduce cost, risk and project time. One recent example of a machine builder gaining considerably from adopting this tightly integrated approach to automation was a project recently undertaken for a customer in Ireland.
This manufacturer wanted to automate a disc polishing process that involved the hand loading of product onto caddies for cleaning and polishing, and then unloading them using a non-contacting tool. Unfortunately, the process suffered quality problems attributable to manual product handling issues. Manual handling also resulted in damage to the polishing pads on the machine, leading to spoiled products and subsequent downtime.
The issue with the changing of the pads on the polishing machines was identified as human error and highlighted a need for greater accuracy in their placing to ensure efficient machine operation. The decision was taken to automate the entire process, including the placing of the polishing pads.
At the tendering stage, the machine builder proposed a system comprising a robot, a servo drive and a conveyor. During an earlier demonstration, Rexroth helped the machine builder to satisfy the end user that the positioning accuracy of the servo drive was sufficient for their application – a simple expedient that helped them win the contract.
The machine builder’s brief included an upgrade to the existing polishing machines so they could be loaded, unloaded and cleaned automatically. This upgrade involved a Cat 3 safety system configuration and included a number of production trials, minor modifications and robot teaching procedures.
From the outset, Rexroth’s ‘Big Bang’ concept delivered a number of advantages for the machine builder. Essentially, the use of common mechanical standards across many of the company’s technologies and ease of product interoperability across these technologies, greatly simplified the systems integration process.
The upgrade
The upgrade involved integration of several compatible Rexroth platforms, including an EcoDrive servo system with DeviceNet connectivity, a VarioFlow conveyor and EcoSafe safety guarding. This fully automated system transfers caddies of product via the VarioFlow conveyor and delivers them to the robot where they are then picked and placed into the polishing machine. When polishing is completed, the robot retrieves the products, moves them through the cleaning process and finally places them back on the caddies. The conveyor then delivers them to a point where they can be unloaded to go forward to the next stage.
As well as being pleased with the technical sophistication and robustness of the equipment, the customer’s project team was also very happy with the service and support that Rexroth was able to offer. According to the engineering manager, any time his team wanted information or support from Rexroth it was always forthcoming. “We have also had an operation and maintenance training course to make our staff fully aware of the functionality of the equipment and give them the knowledge to alter it,” he says.
Reducing the training burden
As with many elements of using a single supplier, there are economies of scale concerning training provision. On a typical machine, if a manufacturer is running a three shift system, there can be as many as 21 different training sessions to manage as the multiple vendors conduct training on the design, operation and maintenance of their particular part of the machine. With a single supplier this is reduced to three training sessions, one for each shift, and as in this case the operation and maintenance course was tailored to cover only the components and systems used on the machine, providing further time and cost savings.
Placing value on the ‘engineer-to-engineer’ rather than the ‘salesman-to-engineer’ interaction is part of Rexroth’s ‘Big Bang’ marketing philosophy. This, along with the company’s global presence and support structure, makes the transition from drawing board to completion in the field (wherever in the world that may be) as smooth as possible.
The machine builder on this particular project is apparently now convinced of the wisdom of going down the single supplier route. The managing director not only pays tribute to the support and assistance that Rexroth gave his company, but now confirms his intention to include Rexroth’s products as part of future tenders for servo control projects. “We are currently looking to include the full range of Rexroth automation equipment as part of what we offer,” he says.
Moving from a traditional multi-supplier to a single supplier policy is more likely to involve a cultural shift in attitudes, rather than a change of engineering practice on the part of the machine builder. With the manufacturing sector under enormous pressure, upfront design and build cost is important. But when savings can be made over the whole life of a project – including running costs - simply by the intelligent interlinking of compatible technologies from a single supplier, machine builders can demonstrate a more competitive and attractive approach to their customers’ needs.