Author: Georg Schöpf, x-technik FERTIGUNGSTECHNIK

Automotive suppliers have the challenge of complying with the ever-increasing demands of the OEMs. Large batch sizes of components need to be delivered, just in time, with reproduceable, ever-higher quality. Lightweight construction is of increasing importance and, therefore, so is the manufacture of bigger, lightweight structural components made from aluminum and magnesium.

GF Casting Solutions Altenmarkt GmbH & Co. KG is a premium supplier for this kind of part. The firm was founded in Austria in 1972, under the name Alucon, and later was operated by Mössner Druckguss. It has been part of GF Corporation since 1999. For over 20 years, the firm has focused on manufacturing components for automotive production. Product and process development for high-pressure die-cast components is one of its specialties. »We are constantly facing the challenge of manufacturing bigger and bigger components. To keep the weight of the components as low as possible, you end up with die cast parts with low wall thickness, which creates its own challenges for high-pressure die-casting and manufacture,« explains Reinhold Brunnthaler, Senior Expert for Mechanical Machining at GF Casting Solutions. Over the years, the experts in high-pressure die-casting, from Styria, Austria, have expanded their knowledge and expertise for the necessary process steps. Now, they're in the position to offer the entire value chain, from simulation to high-pressure die-casting to mechanical machining and part coating, as well as checking for efficiency, and seamlessly documenting the entire process.

High level of in-house production
»Our services cover all process steps right up to ready-to-mount components, and we have all the necessary machining methods in-house. Cutting plays an important role in this. Our fleet of machines comprises almost 50 machining centers. With high-pressure die-cast machines with closing forces of up to 4,400 t, we machine nearly 14,000 t of aluminum and magnesium per year and each part requires some form of post-processing«, Brunnthaler justifies the high capacity requirements.

Customized solutions
The CHIRON DZ 25 P twin-spindle machining center, which was first put into operation in February 2020, has a development story that fits perfectly with the process development objective of the GF Casting Solutions site. Dirk Schmid, Head of technical Sales Germany, Austria, Switzerland at the CHIRON Group SE, remembers »We've been working with Georg Fischer for over ten years now. There are more than 15 machines of the CHIRON Group working at the site in Herzogenburg and in Altenmarkt. We knew that the requirements for batch sizes and the dimension of the parts were constantly increasing. Because we wanted to support customers like GF to work more efficiently, we asked GF in 2015, whether they were interested in helping us develop a highly productive, twin-spindle machining center.«

The aim was to develop a manufacturing system precisely tailored to the needs of automotive suppliers for machining structural components. »We compiled a feature list with a precise profile of requirements for a new, twin-spindle machine concept. Of course, we started from the necessary machining steps, but we also rethought the composition of the machine from scratch. A shuttle table concept for equipping the machine during operation, as well as a quick tool changer for reduced change times. We also had to keep in mind the high safety requirements,« Brunnthaler goes into detail about the design.

 Prioritizing stability and ergonomics
The main focus was on highly productive machining of complex structural components. This was one of the reasons that the CHIRON Group opted for mobile gantry design for the new development, rather than the tried-and-tested a traveling column design. »The result was an extraordinarily stable and rigid machining center which also fulfills all our wishes in terms of precision. We found out precisely which factors are relevant for cycle times and focused on those in particular. It became clear that tool changing and workpiece positioning were crucial aspects for this,« Schmid says. The turntables, mounted in parallel on the bridge of the A-axis with an 800 mm spindle distance, can be fitted on the loading space and swiveled in. Both HS motor spindles run on independent Z-guides, enabling mirror machining and compensation of possible component distortion.

Capacity for high productivity
The significant rigidity of the machine allows high dynamics and very fast axis acceleration, as well as fast rapid traverse speeds. Two separate tool magazines with space for 60 tools each, offer independent tool change on each spindle for short Chip-to-Chip times of 3.5 s. With axes of 800 x 1,100 x 800 mm (X/Y/Z), it's easy to machine large parts and the spindle torque of 200 Nm at 20,000 rpm is transferred safely to the tool via a HSK-A63 interface. The new TouchLine operating panel is based on a Siemens 840 D sl.

»The positive experiences with CHIRON machining centers allowed us to win GF Casting Solutions Altenmarkt as a development partner for the new structural component machine. The previous machines are, for the most part, also universal. The DZ 25 P is one of the newest developments from the CHIRON Group, ideal for structural components for the automotive industry. It's a true workhorse in terms of performance, productivity and reliability,« Dirk Schmid looks satisfied as he finishes his explanation. Reinhold Brunnthaler adds, »Our cooperation with the CHIRON Group was really very fruitful. We regularly refined the details together with developers until the set-up was thoroughly perfect. During the installation test phase we actually produced suspension struts for Audi and then immediately moved to three-shift operation. This helps us achieve the current rates of around 270 parts per shift; which is a huge increase in productivity compared to the old system.«

The CHIRON Group also offers a solution for larger structural components now, with the DZ 25 P in one size bigger. The new 28 Series with 1,200 mm spindle distance perfectly complements the CHIRON Group portfolio. Based on the same machine platform, the new CHIRON series are precisely designed for the various workpiece dimensions, covering the whole range of sizes and complex components for automotive and aerospace applications.

Words and text: Helmut Damm, Workshop + Operation

There is a plethora of technology in the ›Hinterland‹, as the region between Wetzlar and Kassel (in central Germany) is known. Hundreds of small and medium enterprises are located in the area, forming a sort of metalworking cluster. Right in the heart of this activity, in Steffenberg, is Aleit GmbH, developing, constructing and manufacturing outstanding fixed and rotating precision tools for milling and turning. If you haven't heard of them, that's probably because Aleit is a behind-the-scenes company. Their customers include a growing number of leading (and very well-known) international tool manufacturers and traders, rather than end customers. The 40-person company has all the expertise in construction and manufacturing to produce smart, almost-revolutionary tool concepts, but it doesn't have the capacity for a global sales force targeting end customers. This makes Aleit a kind of
»Hidden Hidden Champion« in the Hinterland.

Ideas alone are not enough – it's all in the execution
The business, which began operation in 1961, has always focused on the extraordinary and the ambitious. Holger Aleit, son of company founder Gerhard Aleit and father of today's CEO Björn Aleit says, »Right from the start, we weren't looking to manufacture standard products; we were looking to work in the most-demanding field possible in terms of technicality. Our customers still recognize this today, because we not only develop creative tool solutions, we offer a comprehensive, fully documented process, from the moment we receive an order right up to the delivery of an operational tool – including details such as customer-specific labeling and packaging. That's another of our USPs. It's not enough to simply have a fantastic idea for a better tool. You need the expertise to really technically manufacture this idea and execute it in an economical way. Innovations drive our business, so we cooperate closely with the Fraunhofer Institute and other similar institutes. This means we always have our finger on the pulse. In terms of manufacturing, for milling our variants we work with batch sizes between 1 and 200 and we currently rely on complete-machining with automated machining centers and milling-turning machines from the CHIRON Group.«

CEO Björn Aleit trained as a milling/cutting machine operator on milling technology and then was educated in Mechanical Engineering. He worked in various roles in his family company and took over the Executive Board at the end of 2017. He knows the company history inside out, and they have been focusing on precision tools since 1985. Three ›House specials‹ define the business today and their investment decisions.

Base frames for milling tools with inserts
Björn Aleit: »We started by specifically designing and manufacturing the optimum tool bodies, first and foremost the insert seats, around indexable inserts that customers provided us with. The requirements for these steadily increased. Tools, for example, for optical industries with axial running and concentricity of ≤ 5 µm are de rigueur.«

Modular tool interfaces
As time went on, the Aleit team began to wonder why they only focused on the cutting side of the tool and didn't also consider the back-end, taking on and innovating for the interface to the spindle, along with the highly complex interior. Today, in Steffenberg, the team works on all the known interfaces in the market: SK, HSK, PSC (Capto), TS (KM), ABS, VDI, etc.

CHIRON FZ 16 S five axis machining center: The quick-to-retool, flexible robot automation with inventory drawers (right) ensures high levels of productivity.

With the removable blades with interior cooling from above and below (left) and the clamping-turning holder with coolant-lubricant supply via the shaft to the blade (right), problem-solver Aleit had landed two hole-in-ones.

Parting and grooving tools with internal coolant supply and holder
For a long time, Aleit manufactured square shaft holders for turning in the form of clamping-turning holders and blade-mounts with various interfaces. It was always a fly in the ointment for the experts, that the interference contours impeded the feed of the coolant to the key area. Björn Aleit says, »The problem can't be solved with the standard cooling in the VDI tool holder. But the coolant is on the holder to use. So, we developed a sophisticated drill system, which enables the coolant-lubricant to be guided through the blade from above and below with up to 80 bar pressure until it reaches the open side of the blade, even for modular systems. The effects on service life and chip breaking are significant.« Aleit submitted this idea for a patent, changing the international market as the idea was adopted by many big tool suppliers as their standard approach.

Complete machining and automation
In 2007, the firm first made contact with STAMA, which was already a 100% subsidiary of the CHIRON Group SE. Their research for efficient and precise complete machining led them to STAMA and they purchased a milling-turning center MT 726 2C with twin traveling columns. Gerhard Schweicker, Area Sales Manager for the CHIRON Group explains »The MT 726 2C had the USP back then, that there were two, five-axis travel column units on one base frame with integrated turning functionality based on a turning spindle. The new generation is on a mineral cast base frame with a mobile gantry design. This allows both short bars and chuck parts to be loaded from above, and then clamped, transferred and machined flexibly by the spindle. The transfer from OP10 to OP20 is always highly precise. For turning spindle there is one full milling spindle and up to 64 tools ready to use, enabling a totally new kind of heavy-duty machining in comparison to the classic counter-spindle turning machine with a maximum of 12 tools on the revolver. It doesn't get more flexible than that.«

Thereafter, the firm also purchased a MT 734 from STAMA. Regarding long-term, largely trouble-free shift operation of the machines, Björn Aleit talks about his »reliable marathon runners which are slowly getting older, but have been a fantastic investment.«

Investment in lifetime flexibility
The next time Aleit needed to invest was in connection with the complete machining of PSC tools with their various shaft interfaces. The original manufacturers had previously failed to manufacture the complex internal contours including eccentric geometry from one cast. For this task, Aleit selected an F Z16 S five axis which is sold in a package with an individually tailored robot-automation cell. The extremely stable machine concept with a swivel bridge mounted on both sides, was impressive from the start. To this day, the intelligent and, above all, highly flexible and quick-to-change automation unit makes the big difference to productivity.

Milling-turning complete machining
Aleit chose the current series of milling-turning centers with mobile gantry design from STAMA, with the highest level of configuration. Roland Ranisch, Sales partner at the CHIRON Group says, »In the end, it was about the universal combination of round profiles, right-angled profiles and chuck parts which need completely automated machining using millturn. The two-sided clamping takes place with automated, correctly positioned internal transfer and five-axis, interpolated processes, so that the components leave the machine partially finished. Many products then go through the hardening process, which is followed by a complex grinding process on an ultra-modern CNC cylindrical grinding machine in a climate-controlled room. The six-sided machining based on multitasking ensures that machining can take place on the front and back without a loss in quality.«

It's possible to work with bars up to a diameter of 102 mm, while chuck parts can have a diameter up to 300 mm. The supply and discharge belts can move individual parts weighing up to 25 kg to and from the workpiece gripper, which is located between the two working chambers and manages the transfer from the main spindle to the counter spindle for chuck parts. The machine has an autonomous tool inventory of 64 tools per working chamber and an additional, up-to-240 tools in the auxiliary magazine which is connected via shuttle.

In response the heat transfer or the mutual influence of the machine chambers while working, regarding vibrations – machine operator and foreman Daniel Scheiter has a clear statement, »It promises a lot, but in this case, it lives up to our expectations. I never experience either problem in my daily work.«

Customer-focused even in the future
Aleit is, of course, ISO 9001 certified and is therefore very well-positioned today. It now has its own product range that fills an entire catalog. It is also noteworthy, that the firm completely tests all finished parts including documentation on a Leitz climate-controlled and decoupled 3D coordinate-measuring device pmm 654, with a measurement uncertainty of only 0.6 µm, the option for burnishing, the various types of beam (with corundum, glass balls or stainless steel balls), cylindrical grinding and laser marking.

But Aleit always has its eye on the future, because the challenges are only getting more demanding. Digitalization is a hot topic. As well as DNC-operation, after an ERP-update, Aleit will look to fully utilize the possibilities of the digital systems in the CHIRON Group SmartLine portfolio. They are surely on the right track with the idea of sensor-protected, intelligent tools for a digital fingerprint across the entire process. With this in mind, a continuing, trusting collaboration between Aleit and the CHIRON Group is guaranteed.

For more information: www.aleit.de

Many different components but only small batch sizes: Motorcycle accessories manufacturer SW-MOTECH was hunting for a suitable machining center to cope with the challenge of using automation to manufacture 400 reoccurring parts in batch sizes of 30 to 200 pieces. »After we'd ascertained that all well-known machining center manufacturers could mill well, it was the way the CHIRON Group took such great care to understand our problems that finally made the difference,« says Kai Jockel, Managing Director of SW-MOTECH GmbH & Co. KG and responsible for production there. Together, they found a solution with the FZ 15 S five axis machining center and designed a concept for the robots and clamping technology which was appropriate to the variety of parts. The system has now been running flawlessly in three-shift operation for a year. These are the most important points of the application, but there's plenty more interesting things about the project and customer.

First and foremost, SW-MOTECH has interesting beginnings, with its origin on a ferry ride between Italy and north Africa. In 1994, mechanical engineer Jürgen Swora developed a tail tank for his Honda Africa Twin for a motorcycle ride to Libya that he was taking with his friend Jörg Diehl. The bikers met on the ferry crossing to north Africa, where there were not only lots of riders, but also a motorcycle dealer who was interested in the tail tank.

Everything started with the invention of a tail tank
From there, grew a business idea which led to the founding of SW-MOTECH in 1999. The third member on board was Kai Jockel, who remembers the time well, »We started back then on a farm, in an old barn, with a drill and a welding device. Today, we have a headquarters in Rauschenberg, in Hesse, Germany, 180 employees, a second production location in Czechia and sales branches in Spain, France and now in the USA too.«

Right from the start, the company focused on the production of premium motorcycle accessories produced in-house. Our recipe for success was products that no-one else was offering,« the managing director explains. Thus, in 2000, the first removable luggage rack in the world, based on the Quick-Lock bayonet locking system, became their USP. This was followed, five years later, by the patented Quick-Lock mechanism tank ring for mounting a tank bag with just one click. »This pioneering product made sure even the OEM motorcycle manufacturers knew who we were, when before we had only supplied traders.«

The workload required a third machining center
And with that came new requirements for production. While at the beginning, the majority of orders were welded components, now increasing numbers of milled components were needed. And so, the first three-axis machining center found its home at SW-MOTECH. »With VCP 800 from Mikron, we very slowly started getting into milling, only to then discover, quite quickly, that the machine was at full capacity,« Jockel remembers. Then came the second three-axis milling machine and, when that too was running around the clock, the company went to the EMO 2019, in Hanover, in search of another machining center. The slogan »Tool change in 1.5 s« drew Jockel to the CHIRON Group stand at the exhibition.

»Although the speed, in this respect, is not remotely relevant to us,« the Head of Production says with a grin. »The part numbers in the motorcycle industry don't really compare to the automotive industry. 30 parts is a typical batch size for us, and we also wanted to mill prototypes or mechanisms on the new machine. However, we still wanted automated manufacture of a wide range of parts.«

The clamping concept played a decisive role
That's why the clamping concept, for the around 400 different components, played such a decisive role. »We needed to find the balance between the level of investment for the machine and for the mechanisms, because the workpiece side couldn't cost any more,« Roland Ranisch, CHIRON Group Sales Partner, describes the initial situation. »So, using a variety of mechanisms for each part, about half of which would only be used once a year, wasn't an option.«

Together, they developed a robot and clamping concept, which also required compromises on the part of SW-MOTECH. The unmachined parts, or blanks, for certain component groups were thus standardized, so that the same mechanism could be used more often. »Because it's quicker to mill off 5 mm excess material from a blank, for example, than to re-mount,« Ranisch explains. For Jockel, the be all and end all was to remain with the vice as the final clamping element. »This meant we only had to invest once in the base device with zero-point clamping system and only need to adjust the second clamp at the top with the vice.«

Rack with six device positions and a station for eight double-grippers
The final solution now comprises a Fanuc robot, a paternoster rack with drawers for the blank part pallets, a rack with six device positions and a gripper station for eight double grippers.

The pallets are 600 mm × 400 mm and have space for up to 52 parts. »The store is designed for a runtime of eight hours, with 24 pallets and, thanks to the six device positions, six different components can be machined per shift without operators needing to manually interfere. The average machining time is three to four minutes,« Ranisch describes normal operation. Bastian Feußner, who is responsible for machining, describes the process of changing products, »The robot takes the device out of the machining center, changes it for a new one and then takes the gripper with the correct clamps. The pallet with the new blanks is prepared from the paternoster rack and the robot places the part in the machine. The following step, thanks to the double-gripper, is when the robot takes the finished component and places the blank part in. The production order always specifies whether the necessary devices and gripper are in the racks. A complete switch over takes around five to six minutes.«

The number of clamping positions needed to be reduced
Choosing the machine itself was relatively simple, and they decided on the FZ 15 S five axis machining center because it was best suited to the range of components. There was, of course, a reason that it had to be five-axis this time. Managing Director Jockel explains, »We often needed up to four clamping positions for our three-axis machines. Five-axis machining allowed us to not just reduce the number of clamping positions, but also gave us more options for more expressive design parts on the motorcycle.«

The acceptance parts were milled in the required quality
The CHIRON 15 Series machining centers are fundamentally standard machines, but the options catalog includes around 300 positions for individualization. »For SW-MOTECH, because of the customer-specific design on the workpiece-side it was, again, a turnkey project, including acceptance and production monitoring,« says Ranisch. A forged part for a frame and an aluminum profile were milled to the required surface quality and precision, and after three weeks of support from a Chiron application engineer, SW-MOTECH was able to operate the system without aid.

Now, that really is the whole story and all that's left is to sum up. Here, the experts Kai Jockel and Bastian Feußner thoroughly agree, »The system makes what it's meant to make and has run without a hitch since installation. And that's just how we like it.«

For more information: https://www.SW-MOTECH.info/en/