All the colors of the rainbow at Top Speed  

Toolmaking in the Champions League 

With two new large portal milling machines, Sinumerik has now made its debut in the manufacturing operations at Concad GmbH. The result: significant competitive advantages thanks to services, technologies and smart IT connectivity via edge computing. Operation, process reliability and dimensional accuracy are impressive – and a great deal of time is saved by the simply excellent quality of the surfaces which reflect all the colors of the rainbow even without remachining.      

Ready for some superlatives? 

20-tonne blanks that cost six-figure sums and are 17 tonnes lighter after 800 hours of machining, but produce dies that are then dimensionally accurate to the limits of what is technically feasible. And whose surfaces then reflect all the colors of the rainbow. This is the domain of Concad GmbH or, to be more precise, its "Toolmaking" division in Walldürn, Germany. There is no room for mistakes when manufacturing such workpieces. What's more, every minute saved is valuable because the market is hotly contested. 

To be competitive here, you need the necessary expertise, thermally stable production conditions, and the right machines with the right drive and control technology. The CNC plays a decisive role here, firstly in supporting the production technologies, but also because Concad's experienced application engineers specify the program sequences generated during job preparation in technological terms – interactively and directly at the machine. The CNC's ease of operation is an important efficiency factor here.  

In search of the right machine 

Two new machines were required to modernize and expand Concad's production: one machine for heavy-duty machining of the free-form surfaces and milling of the regular geometry, and a second, lighter machine for finishing the surfaces. With a milling test part that seemed to be easy, but had some mean and tricky aspects to it, the Concad team went on a benchmark tour of the European machine tool industry. The surprising result: the "old lady" in the plant, an 18-year-old Droop+Rein high-gantry machine, produced just as good surfaces as the modern machines – in terms of machining time, it even ranked mid-range. 

A test part that fits the bill! 

Droop+Rein is now part of Starrag AG. Starrag helped Concad mill the test part on state-of-the-art Droop+Rein FOGS machines. These machines were equipped with Sinumerik. The result was impressive due to the minimal machining times and excellent surface quality. Given the dimensions of the machine and the masses being moved, "it's like a truck racing around a track at the speed of a Formula 1 car," says Klaus Schwab of Concad's management team.

 

Now, in any case, there are two new Droop+Rein machines in a new, fully air-conditioned hall: a FOGS HD 50 150 R75 C and a FOGS Neo 50 80 N40 C.

Smart control options for increased productivity

Both machines are equipped with CNCs from the Sinumerik 840D sl series, and the very user-friendly smartOperate control is already benefiting from components from the latest Sinumerik One CNC series. Motion control is based on Sinumerik smartMotion technology with the Top Surface and Top Speed options. The machines are connected via Sinumerik Edge to the IT system in an efficient and intelligent way without burdening the CNC. 

The control system – new for Concad – proves to be a door opener to new market segments

New machines, high-end products, and even a new control system – no wonder the workshop team was a bit apprehensive. But their concerns were quickly forgotten after the first workpiece. "We milled the first motor hood right away, and it went completely through at the first attempt. The machines and the control system were spot on," recalls Klaus Schwab, and the workshop team was impressed by the operation right from the start.

"Sinumerik is a thoroughbred toolmaking control system and additionally offers a whole range of integrated features and expansion options – it's brilliant!" 
Klaus Schwab, Concad Wallduern, member of the management   

"We'd already realized that a straight toolmaking control system was no longer sufficient. A CNC has to be able to handle much more and, for example, provide functions that are required for mechanical engineering," notes Klaus Schwab. "Sinumerik is a thoroughbred toolmaking control system and also offers a whole range of integrated features and expansion options – it's brilliant!" 

 

For example, Concad recently received an order for a space project thanks to the CNC's expanded IT capabilities. In such cases, a substantial amount of data must be collected during production for downstream evaluation. With a different control system, it would have been difficult or even impossible to bid for the project, according to Klaus Schwab.

Top Surface, Top Speed: the high-end machines benefit from the "milling package"  

The machines demonstrate what the Sinumerik "Milling" technology package can do – especially if it has been optimized with mechanical expertise, as in this case. It reduces machining time while maintaining maximum surface quality. The "Top Surface" option achieves a surface quality that is second to none. The margin defined by the local workpiece tolerance is used to smooth the position setpoints in a way that visibly improves the surface quality. The "Top Speed" option then optimizes the speed profile of the machining operation in such a way that resonant frequencies of the machine are not excited. This speeds up machining without compromising surface quality.

Surface shining in the colors of the rainbow

The rigidity of the drives and machine components of the new Sinumerik-controlled machines in combination with the on-site and climatic safeguarding of the static dimensional accuracy - these are solid foundations for further optimization of production quality. For example, the dynamic influences were mechatronically minimized, while systematic use was made of the functionality of the Sinumerik control system with its Sinamics drives. Before finishing operations, the complete machine is also volumetrically measured using VCS-A5+ and VCSrotary, and the respective tool heads and tool lengths are adapted with milling head calibration cycles. Overall, this raises the machining accuracy of these large machines to the level of measuring machines. 

 

The result is that the huge workpieces are dimensionally accurate to a µm, and their surfaces reflect and shine in all the colors of the rainbow.

Milling in the Champions League 

Thanks to their modernization efforts, Concad now has the machines it needs to meet the increasing demands on press tools in the future, and for the production of even the most demanding workpieces for mechanical engineering and other high-end applications. Particularly in the case of press tools for the automotive industry, they are continuously "in search of the μ" as regards surface quality and dimensional accuracy. At Concad, troubleshooting is now limited by measurability. The foundation of the machines, which is set several meters deep, the air conditioning of the hall, the temperature management within the machines – all of this helps in the interaction between control, machine and application to keep the process as close to the optimum and as stable as possible. All these different aspects mean Concad can continue milling in the Champions League and produce workpieces with rainbow-colored glossy surfaces, accurate to the µm, and at top speed with high performance.

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