With more than 36,000 employees and 62 locations in 25 countries, Bombardier Transportation is the world's largest manufacturer of rail transport technology. The true heart of rail technology beats in Germany where this division of the Canadian conglomerate is headquartered. The plant in Netphen produces carriage bodies and bogies for rail vehicles of all kinds - from the tram to the high-speed train.
Mind you, not only for its own trains: for example, Bombardier Transportation supplies Siemens Mobility with carriage bogies for the next generation of ICE train. Between 2500 and 3000 carriage bodies and bogies of all kinds are manufactured, painted and assembled to final completion at the Netphen plant per year. Despite the economic crisis, order volumes have risen over the last few years, to a point where the plant with its workforce of 700 is now almost at full capacity. The acquisition of new machines and tools is not all it takes to get on top of this amount of work - the company has also had to improve its productivity and to reduce the relatively long periods of downtime caused by retooling of its machines and the loading of new NC programs. This has all been accomplished through the introduction of a modern 3D-CAM system: in early 2011, Moldtech in Netphen installed the first TopSolid workplaces.
Optimization of tool setting operations
The CAM programmers used to produce their NC programs for machining bogies using a 2 1/2D programming system, something which was time-consuming as well as prone to faults. "We programmed from 2D drawings which means that we never really knew what the chassis really looked like and if we had taken proper account of how to machine all of the interference edges", explains applications specialist Michael Kringe. Furthermore, the CAM programmers were only able to specify tools approximately in advance because they had no direct access to the data in the old Access tool database. That meant additional work for the colleagues in Tool Setting who had to compile complete tools on the basis of the approximate tool list and drawings. It was often not until the NC programs were being run for the first time that tools were found to be either slightly too short or too long, at which point further retooling was required.
Alongside a 3D-CAM system the applications specialists in Netphen therefore urgently needed an integrated tool management system that would enable them to access real tool data during the CAM programming stage. However, the new solution not only had to support CAM programming work, it also had to assist with the administration of tool inventory and storage location as well as the ordering system. And it should be able to communicate with the measuring system. "We wanted to have a solution from a single source", states CAM programmer Damian Sakwerda. "Since we had already been working for a good while with a Zoller presetter, we decided to purchase a new unit and to invest in the Zoller Tool Management Solutions system."
The main advantage of Tool Management Solutions is that the company, instead of having several databases, now just has a single source for all tool data and, thanks to the integration of the presetter, real measuring values can also be recorded. That is important for a number of reasons, not least because some of the tools get reground, which means that diameters and lengths can vary slightly. The database contains all the information required for machining purposes, and all of that information is pretty much available at the touch of a button. That not only saves time, it also ensures that fewer errors are made when tools are being provided, a point about which Rüdiger Hof and Sergej Ponomarenko from the Adjustment department are in full accord.
The Zoller Tool Management Solutions system comprises a modular solution that not only administers the article characteristics and technology data of tools and components, but which also is aware of their respective storage locations. This dispenses with the time-consuming search for tools in companies, leading to enhanced availability which in turn reduces the number of tools needed in inventory. To know how many tools are going to be required and to know where they are stored is particularly important in a plant like Netphen where a vast array of different tools are employed, and where their paths may criss-cross many times: tools leave Inventory to go to Presetting, into buffer storage and magazines, then to the machines, between which they may get swapped over several times. At present there are about 2500 complete tools in circulation - 1200 of those just for the four boring/milling centers from Bimatec Soraluce, often used in multiple configurations to be on the safe side. Kringe estimates that the Zoller software should help to achieve 25 percent cost savings in tool costs, currently amounting to approx. €200,000 per annum.
CAM with integrated tool management
The scope for integrating TopSolid'Cam and Zoller Tool Management Solutions was a compelling ground for deciding in favor of the Missler software - but by no means the only reason. A total of four CAM systems made it through to final selection and they were all tested against one another on an identical workpiece. TopSolid'Cam convinced the evaluation team through its ease of use, its comprehensive range of functions for import and the preparation of 3D models from third-party systems (the bogies are modeled in Catia), the clear presentation of machining operations and, above all, the powerful simulation functions in the context of the machine environment. Another key feature was that Moldtech proved to be such a capable partner in respect of implementation, (re)training and support for the CAM solution. "Thanks to the great support from Moldtech the move to 3D was very easy for us", states Sakwerda.
Working together with Zoller, Moldtech programmed the bidirectional interface between CAM system and tool management. The CAM programmers key their desired article characteristics and properties into Page 4/5 TopSolid'Cam and gain direct access to the tool data in the Tool Management Solutions system. That simplifies their work and also improves the reliability of the NC programs. To be able to use these tools to simulate CAM programming, you do of course need to have 3D models. These are usually created from the article characteristics as bounding geometry and made available to the CAM system. However, on complex contours, they can also be generated manually and stored in the tool database. There is also scope for importing 3D models from manufacturers' catalogs in neutral formats. The list of tools used for NC programming can then be handed back to tool management where it can be used directly for generating the setting sheets, something which significantly reduces the workload associated with adjustment operations.
Moldtech not only dealt with the programming of the interface for tool management but also with incorporation of it in the plant's machinery. A particularly challenging aspect was finding a way to support the relatively complex drilling/milling units from Bimatec Soraluce, equipped with toolchanging heads (indexing turrets). Depending upon which surfaces of the chassis required machining, the tools can be fitted in a fixed head, an angle head or a pivot-action orthogonal head. Due to the fact that machining with TopSolid'Cam is programmed in a virtual machine environment, the kinematics of the indexing turrets need to be simulated reliably with their degrees of freedom, and translated accurately into machine language. The kinematically prepared machine models were provided by Moldtech together with postprocessors. Bombardier Transportation has standardized machining operations on its various sizes of drilling/milling units to such an extent that only one postprocessor is required. It took a while to adapt and optimize this postprocessor because Moldtech not only had to simulate machinespecific functions but also had to depict a few company-specific machining cycles. By way of example, the CAM programmers have for some time been using a subroutine technique that had to be made available within the new environment: "Operations such as milling, lineby-line milling or trimming can be set up just once as a subroutine that is then called up several times at different feed depths", explains Sakwerda. This delivers a number of advantages, one of which being that the NC programs can be relatively lean which makes them faster to bring on stream and work with.
Halving the positioning time
The milling and drilling work involved on a complete welding frame can take up to 22 hours, depending on complexity level. It is therefore easy to picture just how much time it costs to bring a completely new NC program on stream step by step. Kringe estimates that these positioning times for the machining of a new workpiece have been cut by 50 percent. Thanks to the powerful simulation functions in the CAM solution, programmers are able to detect possible collisions while still only working on the computer, which greatly enhances the safety and reliability of operations. Furthermore, the tool journey times to and from inventory/machine can be simulated and optimized in respect of machine operating time. The cost savings possible during the running-in stage are achieved largely as a result of fewer programming errors being detected out at the machine that require troubleshooting and remedial action. Thanks to excellent integration of CAM solution and tool management, it has also proven possible to cut the time required to tool and retool a machine because the Zoller Tool Management Solutions system knows which tools are already available on each machine. In practice, this means that it no longer takes four or five hours to implement machining of a defined workpiece on a different machine: that time is now cut to between two and three hours. "Thanks to 3D programming and integrated tool management, we have become substantially more productive in our machining operations", concludes Sakwerda with emphasis. And Rüdiger Hof from the Setting department added this comment: "Today, we can work in a much more relaxed way because, thanks to Zoller, faults have pretty stopped occurring."