With the introduction of Edgecam, ZF Passau GmbH has extended its use of 3D-enabled technology throughout its production planning. By interfacing with the company’s existing CAD system and 3D CAD models, the software is generating efficient NC tool paths.
With annual sales of around 12 billion Euros and 120 manufacturing plants in 25 countries, ZF is a significant global supplier to the world’s automotive industry. The prestigious ZF brand is synonymous with the supply of high quality drive train and chassis technology to domestic, commercial, construction and agricultural vehicle manufacturers around the world.
Part of ZF Friedrichshafen AG, ZF Passau GmbH, manufactures transmission systems and axles for agricultural and off-highway vehicles as well as forklift trucks. Factories1 and 2 at Passau produce low volumes, with just-in-time batches of 1 to about 250 units, matching the capacities of its customers. A total of 600 CNC machine tools are available for production, and due to product variation about 800 setups occur daily with changes of workpieces, tools, equipment, and NC programs. This represents a formidable logistical challenge for the local production planning unit, whose aim is to ensure efficient production.
Facing the constant pressure to compress the time between development and the start of the machining process, ZF Passau GmbH is negotiating a tightrope between the increasing variety of models and shrinking product life cycles. Supporting this fine balance starts with the Pro/Engineer 3D design tool, which is used throughout the Group. The subsequent process steps are now also becoming 3D-enabled.
The decision to use the Edgecam 3D CAM system from Planit was taken in 2007, moving the 3D technology into the production environment. Edgecam’s ability to meet ZF’s technical specification for a 3D CAM system was clear from the outset and the introduction and ongoing implementation of the software has been supported by Planit’s German distributer, Wecomp GmbH. “This contract with ZF to purchase 50 Edgecam licenses worth around 800,000 Euros represents a further milestone on our road to becoming the leading CAD/CAM systems provider for the automotive sector,” says Manfred Kukla of Wecomp’s management team.
Ultimately the plan is for all 3D programming for the CNC lathes and machining centres to be completed by 2010. The FATool resource management system, from FASys GmbH, will simultaneously be expanded for 3D tool management. The use of a 3D NC simulation program completes the process chain and will be used to ensure collision-free, production-safe NC programs.
The twin drivers for adopting 3D-enabled technology are process acceleration and improved workflow between design, production planning and NC programming. Here, the Production Service department has played a major role in the implementation and it is tasked to develop production planning to provide further improvements. Practical concepts for process optimisation are being continuously developed in close conjunction with the Production department.
Until now production planners have had to revert to the 2D drawing level, because the previous 2D CAM system could not process CAD data. Now they can directly load the Pro/Engineer CAD models with a single mouse click, using Edgecam Solid Machinist. Edgecam also offers planners additional options with which every individual processing step can be rationalised. Thanks to full associativity with the CAD model, 100 per cent error-free data transfer is possible in Edgecam. All the process related information stored by the engineer is read, interpreted for production and linked into sequences of operation.
Commenting on the implementation of Edgecam in ZF manufacturing facilities throughout Germany, Peter Robl, team manager, Production Services says: “Edgecam is the only system that delivers the process automation tools we demanded during our evaluation of 10 CAM solutions. The degree of integration and interoperability we achieve between Edgecam and our corporate CAD solution Pro/Engineer, enables us to take component designs and automatically generate and apply optimised tool paths. Another key aspect of Edgecam is its seamless compatibility with the FaSys tool database system. The productivity efficiencies we achieve with Edgecam give us a significant return on our investment.”
Common families of components can be combined by means of the macro language into standardised processing models. The processing of new parts based on similar existing components is also simplified; the existing part serving as a template that only needs modification. Today, drawings are no longer necessary in production planning.
The potential for increasing efficiency in the new programming process does not stop there. The production equipment required for processing each job is held by the NC management system FATool, and must also be available in Edgecam. Direct transfer of the entire inventory, comprising some 10,000 complete tools alone, is enabled by a direct interface.
In practice, the production planner starts the CAM system in FATool and using the input dialog, quickly retrieves the appropriate resources for the production task from the classified database of machines, jigs, fixtures, and tools. This method, which is very intuitive for the user, is continued in 3D tool management.
The 3D tool management module of FATool, introduced simultaneously with Edgecam, simplifies the preparation of programmed and simulated models of complete tools. Stored templates, known as master models, facilitate configuration of tool components by means of class lists of characteristics. With the Pro/Engineer CAD system integrated in FATool, they are automatically ‘assembled’ using defined sectioning points and passed to the CAM and NC simulation system, without the need for any knowledge of CAD on the part of the planner.
FATool, the system-integration ‘hub’ of this process chain, has been used in Passau since 2005. The program not only holds the entire production-relevant hardware and software, but also communicates bi-directionally with both site logistics (ERP/SAP) and the Axalant PDM system. Every NC data record, of which there are now more than 90,000, is saved by FATool. The same applies for DNC operation; if the operator makes a program correction at the machine, this is reported back to FATool.
The finished toolpath is translated using post processors into the machine language of the selected CNC machine. ZF Passau has been supported by specialists from Wecomp in the development and adaptation of the post-processors. At the request of the Production Service department, standardised post-processors have been created, each tailored to a group of machine tools with similar dynamic features. This allows planners the option of transferring production to a number of machines without going through the post-processing sequence again.
Transmission of NC programs and actual tool data to the CNC machines is performed by the DNC software FAPcd, which links all the existing machines to the central operational data management system. Within the production islands on the shopfloor, standard PCs take over the control function; here, operators can view the programs and transmit them to the machines.
Despite the high degree of automation within the new system environment, responsibility for the design of the production processes remains with the planners. Freed from routine work, they can focus entirely on applying process expertise. Design and production planning are now more closely linked because, as early as the design stage, models can be transmitted to CAM and NC simulation programs to test production feasibility.
Edgecam’s country manager for Germany, Nick Spurrett, says: “By aligning its corporate CAM strategy with Edgecam, ZF shows that its manufacturing philosophy of investment in automation is very much in tune with our continued development plans. With operations in both high and low labour cost economies, ZF needed to select the most appropriate CAM solution for future implementation across the whole business. For global organisations such as ZF, simply chasing low wages is not enough. Labour costs are only one element in a complex equation that defines ongoing competitiveness.”