Author: Rüdiger Kroh, Schlütersche Fachmedien GmbH

Advancing digitalization
The Arena of Digitalization was opened in May 2017 and so was pretty much the starting point for the current project. »Under the CEO of the Siemens Motion Control Business Unit, digitalization was brought to life and constantly expanded and modernized,« explains Eugen Edelmann, Head of Prefabrication and Special Motor Assembly at Siemens in Bad Neustadt. Torsten Franz, responsible for PLM Integration and Innovation, looks back to the early days: »The topic of digitalization in metalworking was increasingly coming to the fore at the time and we were a plant with a lot of mechanical processing, the relevant machines and experience with the NX Software Suite.« Therefore Bad Neustadt was converted into a showcase plant.

»There should be feedback from the manufacturing floor to the developers on what is needed, possibly should be changed or optimized and what is working.« So that's the back story. For the implementation, a partner on the machine tool side was sought and in this case found in the CHIRON Group. The company, headquartered in Tuttlingen, Germany, chose Siemens NX as its CAM system about five years ago. »This means that all our products are compatible and we have the same basis for mapping the entire process chain from A to Z with different modules,« says Markus Schimansky from the Technical Sales of the CHIRON Group SE. And Franz adds: »The products of the CHIRON Group fit together with ours like a jigsaw puzzle and there is interest on both sides to advance digitalization.«

Measuring the degree of utilization
During implementation, the first step was to connect all machining centers in electric motor production to the network in order to create transparency. This was very important and, by calculating the Overall Equipment Effectiveness, showed that the machines were not yet fully utilized in some cases. This is because there is often no distinction between use and availability, as Schimansky makes clear. »Since we also use the term available to describe a machining center that is waiting for blanks or being set up. I can only record and improve the degree of utilization firstly by looking at when the machine is running, but also how long it is standing and why.«

The second step was then to integrate and test various software tools piece by piece. Applications were developed jointly and by the end, there was supposed to be a continuous process chain from CAM to the simulation-tested NC program available, so that the operator only had to press the start button.

»If I have this complete process chain, the set-up time is easily only half as long,« states Schimansky. The Production Manager states the corresponding target: »We expect to increase productivity in prefabrication by 7% each year.«

Mapping the complete process chain
This specific project involved the machining of gray cast iron bearing shields and flanges for servo drives of the Simotics S-1FT7 series – these are permanent magnet synchronous motors with very compact dimensions. Franz reports: »There has been a trend there in recent years toward larger quantities. We had several machine tools in use for the product range, but they did not produce as efficiently. Therefore a double-spindle machine was the obvious choice for expanding capacity. So the concept was set and the choice fell on the CHIRON DZ 25 P five axis machining center with pallet changer and a spindle distance of 800 mm, which we decided on because we also wanted to be flexible for larger components. The fact that the spindles are adjustable in the two axes X and Z also spoke in favor of the machine. In addition, we produce aluminum components for the asynchronous main spindle drive on the twin spindle machine with a cycle time of 2.5 to 3 minutes, which we were previously purchasing from an external supplier.« During operation of the machine, which was installed in March 2021, another design feature proved to be advantageous: The separation of the loading and operating sides. Programming is done on the operator side and the large window with a view of both spindles is located in the working area. On the loading side, this allows for optimal material supply and removal so that the operator can load cleanly. This also simplifies automation, because the robot and safety fence are located in front of the loading side, while the operating side always remains freely accessible.

Virtual machine reduces set-up times
A special feature at Siemens is that the double-spindle machine, which is operated in three-shift operation, is set up at least every two days. »Currently we are machining about 20 different component variants on the DZ 25 P,« says digitalization expert Franz. »During set-up, the main effort is on the clamping devices and we have further reduced the time by converting from mechanical to hydraulic clamping. Otherwise, only the NC program is changed, because the required tools are all in the magazine with 2 x 60 places in the machine.« Schimansky adds with regard to the general assessment: »Here you can see that a twin spindle machine pays off even for smaller batch sizes when the preparation time for set-up is very short thanks to the virtual machine and the ProcessLine system.« So back to digitalization. Siemens uses almost all digital solutions from the CHIRON Group SmartLine software portfolio. For example, the ProtectLine system is used for process monitoring, with which collisions can be avoided on the basis of a digital twin of the machine model. »The simulation in the control system runs 0.8 s before the real machine, so that a crash is reliably prevented,« explains the sales engineer. Adaptive feed control is also installed on the Sinumerik 840D solution line control system. During the process, it changes the feed data from the real load data. Franz describes: »The NC program for the part remains the same, but the software can adjust the feed rate of the tools up or down within the specifications. For our gray iron castings, this has allowed us to reduce cycle times by 3 to 5% on average.«

A small solution with considerable effect is the retooling program. It is called up in the control system during set-up and then ensures that the machine sorts the tools for the next job, so that they are in the optimal sequence in which they are needed. »This shortens tool change times and when machining aluminum components has enabled a time saving of 4 to 5%,« says Franz.

Output has significantly increased
His final conclusion is correspondingly positive: »The DZ 25 P gives us a much greater output, 50% due to the double spindle capability alone and another 25% via the shorter machining time, because, supported by the software tools, it is much faster. Together with the possibilities from virtual simulation and programming, we were able to significantly increase productivity.«

The next machine already is ordered
It is therefore not surprising that the next CHIRON machine has already been ordered and is scheduled for delivery in early summer. Because it is not intended for such large quantities, Siemens opted for the FZ 16 W single-spindle machining center with the new Sinumerik one control system for the first time. The machine is equipped with shuttle table and two zero point clamping systems. Subsequent automation by the company's own tool manufacturing facilities is already planned. Thanks to the Run My Robot tool, the 6-axis robot is controlled via Sinumerik one, so the worker is only on one operator interface. The extent to which digital thinking has now taken root at Siemens is shown by the fact that just four weeks after the order was placed with the CHIRON Group, there was a request for the digital twin and the postprocessor. The time until delivery of the machining center will be used for process planning and the creation of programs.

More information can be found at: www.siemens.com

Author: Edgar Grundler, Publica-Press Heiden AG

The best example of this is the aforementioned weighing technology of all sizes, and this in turn is inextricably linked to the globally active company Mettler-Toledo. With 17,800 employees – including 1,300 in R&D alone and 8,500 experts in Sales, Service and Support – turnover of $3.7 billion, a broad product portfolio and finally a presence in 40 countries, the company sees itself as a leading global manufacturer and provider of precision instruments and services for use in laboratories and production facilities. The components, devices and individual system solutions are manufactured in production facilities in Europe, America and Asia.

Mettler-Toledo GmbH, Weighing and Instrument Components, plays a very important role in this and is based in Nänikon, Switzerland. This is because the MTWIC department, which belongs to the central Mechanical Manufacturing area, is responsible for production and assembly and is one of the departments located in this plant. Here, the weighing technology cells, which represent the core or the aforementioned mechanical heart of a load cell, are produced primarily from aluminum and five other different raw materials in a monoblock design. Remo Cadonau, Head of Mechanical Manufacturing at Mettler-Toledo GmbH, commented: »We manufacture up to 80,000 engine blocks per year in the milling shop and this is increasing. They are available in four variants with sizes up to 70 x 33 x 110 mm (H/W/L) and in batch sizes of 100 or max. 350 pieces. The running times for the individual workpieces are between 10 and 33 minutes, depending on the 4- or 5-axis machining selected. To deliver the growing quantities on schedule, we currently have six CNC machining centers in use, which produce the parts in staggered two-shift operation, each supervised by a specialist and a trained operator.«

Target: 6,000 spindle hours p.a.
For the production of the cubic parts, for 10 years Mettler-Toledo GmbH has relied on the compact CNC machining centers from the CHIRON Group SE in Tuttlingen, Germany, among others; of these, there is one FZ 12 type for 4-axis machining and three FZ 15 types for 5-axis machining, all of which are equipped with a shuttle table. So naturally, in light of the necessary capacity expansion and the desire for an even higher degree of automation as well as the replacement of an existing machining center, when the evaluation for a fully automatic production system came up, Remo Cadonau and colleagues also inquired with their proven machine partner, the CHIRON Group. Dardan Muslija, CNC Specialist Manufacturing Technology & Maintenance at Mettler-Toledo, and as such responsible for project control and programming up to the handover of the production-ready process technology to the milling shop, explained: »While we were already able to significantly reduce set-up and loading times with the CHIRON machining centers with shuttle table equipment, we are now striving for further performance increases with an even higher degree of automation. The declared aim is to achieve 21 to 23 hours per working day and thus around 6,000 hours of spindle running time per year. In addition, automation also makes sense for us in that, on the one hand, we further increase self-sufficiency and, on the other hand, relieve the trained operators and, last but not least, the process specialists.« In close cooperation with Simon Heim, Technical Consulting/Sales at the CHIRON Group SE for Swiss customers, an individual manufacturing system was configured. This is essentially based on the proven FZ 15 W five axis machining center with workpiece shuttle table, but is however the latest version with extended features, and above all is supplemented by the robot-assisted VariocellUno magazine and loading system for fully automatic workpiece handling.

Next step: Full automation!
Accordingly, the new, fully automated production system for Mettler-Toledo consists of an FZ 15 W five axis vertical CNC machining center with workpiece shuttle table, which has travel distances of X=730, Y=400 and Z=360 mm and operates at spindle speeds of up to 15,000 rpm and a max. torque 140 Nm. Equipped with the well-known very fast automatic tool changer (change time 0.9 s or chip-to-chip time 2.4 s), the optionally extended tool magazine with 64 places, the integrated workpiece changing device (change time approx. 3.5 s) with 2-axis swiveling device (swivel axis as A axis and NC rotary table as C axis) and feed drives for rapid traverse speeds of 75 m/min in the X, Y and Z axes, all the prerequisites for highly dynamic complete machining are already met in the basic version. Other features include: Siemens 840D solution line CNC control system, automatic temperature compensation, Cycle 800 software module including kinematics data for machining tilted surfaces, automatic zero point calculation, reinforced coolant system, Lasercontrol Single F1000 tool breakage control system and probe for measurements in the machine.

The VariocellUno universal, robot-assisted loading and unloading system is installed for fully automatic workpiece handling. Equipped with a 6-axis robot and a pallet stacking system for pallets measuring 600 x 400 mm, up to 24 pallets can be loaded with (sawn) blanks or finished workpieces can be returned to storage during machining, depending on the workpiece dimensions. Since the magazine and loading system is designed as an independent unit and is only docked to the machining center mechanically and in terms of control technology, access to the work/loading area for manual loading and for changeover/service work remains unrestricted.

Output in new dimensions
Now that the new fully automated manufacturing system from the CHIRON Group has been in production operation at Mettler-Toledo GmbH for several months, Remo Cadonau takes stock: »Depending on the dimension, we can accommodate between twelve and eighteen blanks or workpieces per pallet and store between six and eight pallets in the magazine. Based on the respective processing times, we achieve a very high degree of autonomy, so that we are already coming very close to the required running times of 21 to 23 hours per day and the envisaged 6,000 hours per year with staggered two-shift operation. Based on the performance of the machine and the magazine/loading system, and depending on the machining intensity of the individual workpieces, where we have to work with up to 25 different tools, we see the possibility of being able to produce around 25,000 parts per year with this production system alone. Once the process is up and running, all that remains is to manually insert the sawn blanks into the VariocellUno and remove completely machined components at the end. While we were already able to significantly increase output using the CHIRON machining centers with shuttle tables, we are advancing into completely different dimensions with the help of the new production system. The long-standing partnership with the CHIRON Group paid off again, especially since we know the machines and their performance very well and could and can build on a wealth of experience.«

More Information: www.mt.com

Author: Helmut Damm, Carl Hanser Verlag GmbH & Co. KG

Between 2011 and 2021 alone, the turnover of the Rosenberger Group more than tripled and it has now definitively surpassed the billion benchmark. The pandemic-affected years of 2019 – 2020 only left a small intermediate plateau in the revenue curve – the impact of which is already fading. The business areas of the Group outperform each other in terms of their future potential:

• The »Communication & Data Center« deals with mobile communications and data transmission, while the »Automotive« division manufactures connectivity systems for infotainment, e-mobility and driver assistance systems;

• »Medical & Industries« addresses the medical, IoT, autonomous robots and smart home markets;

• »Test & Measurement« supplies delicate precision components for testing and measurement technology;

• and finally, »CNC Machining Technology« manufactures complex mechanical (large-scale) components on a contract basis.

Miniaturization drives requirements to new heights
The high vertical integration of value creation – which extends from the initial idea through to series production – means that all the necessary technologies can be mastered and driven forward by the company itself. It provides a substantial advantage in markets where acting as a development partner is fundamental for the subsequent business with products and services. Each year, around 430 employees in the Fridolfing-based individual part production technology division (»Technologie Einzelteilfertigung«, shortened to »TE«) manufacture around one billion individual parts on approximately 230 production machines – mainly from non-ferrous metals such as brass and copper, but also from aluminum, plastics and, to a lesser extent, steel.

The »Test & Measurement« business unit ensures high capacity utilization of the machines with the precision connectors required in this field. One challenge for manufacturing in this regard is the trend toward miniaturization. The higher the frequencies, the more intricate the testing hardware needs to be – beginning with the connectors. This is compounded by rapid growth, which demands an increasingly higher throughput. And in order to remain at the market benchmark in terms of value for money, short cycle times are also relevant. Christian Schmid, Head of Department TE3, explains the situation as follows: »We have different lines and departments where we manufacture everything from sample parts to small and large series. However, the milling area in TE3 is standalone and must therefore also cover the complete connector portfolio. As a result of the aforementioned trends, we have been under technological pressure since 2019 – especially in the five axis area, where we have been operating with off-the-shelf imported machines until now. When we were then assigned the prototype construction – equipped with two outdated milling machines – the purchase of two five axis machines was proposed as a way of replacing the obsolete prototype construction machines and increasing throughput at a higher level of accuracy.«

Concentrated expertise for a flagship project
Helmut Mühlberger, in his responsibility as Group Manager for Control Production Systems TE3, entrusted the high-value procurement project to experienced specialists: Thomas Fellner and Franz Schuhbäck (Production Process Improvers for Control Production Systems TE3) were assigned project management; Andreas Schiechel (Group Manager for TE3) and Florian Stummer from Work Scheduling rounded off the project team.

Christian Schmid has the following summary for the project, which lasted almost two years: »Our goal was to have contemporary processes on precision machines that can keep pace with developments on a continuous basis. Therefore, the decision was made in favor of two identical CHIRON machining centers of the FZ 12 S five axis type.« Beginning with the initial contact with the Tuttlingen-based machine builder in April 2019, the entire process – from the project planning that took place in May 2020 through to the scheduled delivery of the machines in November 2021 and February 2022 – was conducted successfully despite the pandemic-related restrictions. Numerous discussions and carefully researched specifications provided the basis for this success.

Fast, precise, universal and future-proof
Over the course of the assembly, the essential requirements quickly became clear. As Thomas Fellner puts it: »The wide variety of connectors for test applications contribute significantly to the utilization of our milling capacities. Their complex external and internal geometries require a variety of tools. This brought short chip-to-chip times into focus. At 2.6 s, the FZ 12 S five axis offered the greatest potential in this regard among a comparison of competitors. Intricate connectors also have tighter tolerances. For function-critical dimensions, this is often ±5 µm with regard to shape and positional tolerance, which requires an extremely high level of positional accuracy from the machines. To this end, the CHIRON Group offered us the sample machining of two selected components in Tuttlingen, Germany, which allowed us to make a direct comparison to the previous processes. Both were mastered with flying colors and additionally resulted in significant main time reductions of 30 percent or more. This – along with the other good impressions we obtained from Tuttlingen – dispelled any reservations on our part. It's worth reminding that we'd had no experience with the CHIRON Group prior to that point.«

Franz Schuhbäck adds the following: »Since we also have components with OP 10 and OP 20, which previously had to run through two separate machines, the possibility of complete machining was important to us for reasons of productivity and precision. To this end, the FZ 12 S five axis machines have a secondary clamping surface in addition to the face plate. Furthermore, the analysis of our parts spectrum has revealed average batch sizes between 500 and 1,000 and this is the case for variant-rich repetitive parts with run times in the minutes range. The machines should therefore also be able to be converted quickly. The accessibility and the overall concept of the FZ 12 S five axis machines have noticeably reduced our expenses in this regard. For the not infrequent case that a sample part becomes a series part, rational NC program handling was also important to us, i.e. ensuring a short path to the first good part. Thanks to all the features – from the modern Siemens 840D sl type control system and the fast processors through to the user interface – there's nothing left to be desired in this respect.«

Andreas Schiechel gives the following summary with regard to the perspective component of the selection criteria: »We were looking for a partner with potential in terms of its technology spectrum and product portfolio. A single-spindle machine may be sufficient for us today, but tomorrow, we might need a two-spindle version with a shuttle table. Or alternatively, we may require an off-the-shelf mill-turn solution or a milling machine with a larger design. The CHIRON Group offers this spectrum and thus satisfies the Rosenberger philosophy of seeking partners with whom we can collaborate over the long term, ideally for as long as possible. One of the most important considerations was that the machines also had to meet the requirements for different expansion stages of automation, up to autonomous 24/7 operation. This is something we're currently working on and we're automating one of the machines independently via robot-supported automation with blank handling. The machines offer unlimited prerequisites for this step, also thanks to available additional equipment such as a loader interface and automatic doors, tool breakage detection and a spindle measuring probe, as well as leakage monitoring of the coolant system.«

Exemplary customer orientation
In the interest of short set-up times, Rosenberger docks the clamping devices – which are primarily produced by the company's own fixture construction division – onto a zero-point clamping system that is used throughout the production process. The workpiece change of the saw sections is then carried out manually by the operating personnel for non-automated machines. In order to fully utilize the machine's traverse paths, the CHIRON Group has integrated the zero-point clamping system for Rosenberger directly into the C-axis, essentially doing away with a face plate. This reduces the installation height by 50 mm and also increases the changeover accuracy thanks to a lower number of interfaces. Andreas Schiechel provides further explanation: »Even with such individual requirements, the difference from manufacturers who offer off-the-shelf machines becomes apparent. The price is higher, of course, but a look at the design of the CHIRON machining centers nonetheless proves that we are talking about two different worlds here.«  In general, the project work in partnership with the CHIRON Group has left positive impressions on Rosenberger.

Many questions regarding how to optimize the process and what would constitute the ideal machine had to be clarified and these were answered promptly and patiently. For instance, the experts at Rosenberger had initially come up with a different machine variant based on their own research. The concept in question was a mill-turn center with a bar feeder. Through consultation with Thomas Kehmeier, the responsible sales engineer at the CHIRON Group, as well as Peter Kluibenschädl from the nearby Austrian sales region, overdimensioning was identified as one issue with this solution; other points were also raised regarding the usefulness of certain equipment features. According to Franz Schuhbäck: »Their unobtrusive, competent and cooperative manner made for pleasant working and left an earnest impression on us. This cooperation additionally extends to aftersales, as well. By enabling remote maintenance, we are able to obtain assistance with short response times and little effort. We are still in the process of transferring additional components to the two FZ 12 S five axis machines. If we have any questions, we can get support from Tuttlingen at any time.«