Bacher Medizintechnik, based in the town of Tuttlingen in south-western Germany, is an OEM of surgical instruments. Given the growing requirements for its processes to be validated, the company decided to invest in a CHIRON automated double-spindle machining center – in what represented a visionary step for this industry.
»As an OEM of medical instruments, we are always faced with stricter requirements for our manufacturing processes. Since the beginning of the year, the new European Medical Device Regulation (MDR) has required even greater efforts when it comes to validating and documenting our processes, particularly for removing production-related residual material from components and instruments. So that these rising costs are not generally passed on to our customers, we must not ignore any opportunity to streamline our existing processes. We believe that purchasing the double-spindle five-axis machining center from CHIRON is a key step in this direction since we can operate this machine productively around the clock and with minimal staff supervision, « says Andreas Bacher, Production Manager at Bacher.
Bacher and CHIRON first came into contact at the beginning of 2018. Provided with a specific array of components and their variants to manufacture, as well as a deadline for the complete machining of these components, CHIRON set about its work.
You can find out which ace CHIRON had its
sleeve and what the solution ultimately looked like in this in-depth article in
the WB
Werkstatt+Betrieb trade magazine (german).
For more information: www.bacher-medizintechnik.de
When Märklin, a company with a long tradition, was founded in 1859, the fledgling business – which today would be referred to as a »start-up« – focused on producing tin toys, steam engines and dolls kitchens. Shortly before the Second World War, the company changed direction, and model toys and trains became its main areas of production. After the war, Märklin decided to use diecasting to produce the models.
Author: Oliver Ehm
Published with kind permission of the company Gebr. Märklin & Cie.
»Our products are still synonymous with diecasting,« says Jochen Gaißert, Production Planner at Märklin. »It's of great importance to us because diecasting produces unrivaled tactile properties and quality. The material is relatively heavy and ideally suited to the properties of model railways.«
The expert adds that another advantage is that this material is easy to machine, process and coat, and has many excellent properties for model railways. In particular, diecasting is very heavily used in locomotive production – primarily in the structure and chassis sections. »Ninety-eight percent of all diecast parts we process in our models are produced here at our foundry in Göppingen,« Gaißert explains. »We buy in the remaining parts, such as the drives, since their size means that we can't manufacture them ourselves.« Based in the town of Göppingen in south-western Germany, Märklin brings together all of the manufacturing technologies required to build a model railway. These include tool and mold making, diecasting, injection molding, turning, gear manufacturing, electroplating (nickel-plating), coloration, punching at a small facility, assembly and quality assurance. Göppingen also supplies the subsidiary plant in Hungary with parts, which are then colored and assembled on site, Gaißert adds.
A 36-year
partnership
In 1984, Märklin acquired its first CHIRON CNC machine
– an FZ 16. For the long-established company, this was also its first step
towards complete machining in the chassis area of the locomotives. At the time,
Märklin's employees in Göppingen still produced the drives themselves, with the
processes of chassis and gear machining forming a key production area. Märklin
approached CHIRON in the early 1980s because, Gaißert explains, the
Tuttlingen-based machine manufacturer was the only supplier which adapted multi-spindle
heads and achieved process times which went beyond what the conventional
machinery could achieve with respect to cost-effectiveness. »From an economic
point of view, we'd never have gone in that direction otherwise,« Gaißert
believes. »The CHIRON machines still stand out today thanks to their very short
downtimes and, at our company, we're always performing a lot of tool
changeovers and machining operations.« While Märklin also considers other
manufacturers from time to time, Gaißert states that the downtimes and machine
design are exactly what Märklin needs for its applications.
»For many years,
it's been obvious that we're very likely keep going with CHIRON machines. We
also benefit from the partnership when a new machine series comes out – particularly
when the FZ 08 was released and the company representing CHIRON at the time let
us observe the machine at another business before it came on the market,« Gaißert
sums up. »We then bought a machining center shortly after it was launched.« The
managers at Märklin think highly of CHIRON's proactive dedication. »Together
with CHIRON, we've adapted our interfaces and equipment as part of a major
project. CHIRON was very heavily involved. They even adapted the machine design
especially for us,« Gaißert remembers. »What's more, the machines are very
reliable, stable and operate with high precision.« There are also pragmatic
reasons for Märklin's decision to continue purchasing CHIRON machines.
»There
are great advantages to homogeneous machinery. The variety in control systems
is manageable, the supply of spare parts is excellent and our employees are
included in this approach. They know how CHIRON operates and if there's ever a
real issue, their servicing and programming support is outstanding,« Gaißert underlines.
»For a competitor to come close to us, they'd need to offer significant
advantages.« Märklin tries to avoid having an unchecked variety of machines
from different manufacturers. This is because, in terms of organization, it
would be difficult to manage heterogeneous manufacturing machinery. Under
certain circumstances, you would need to use different tool systems or
measuring technology and this would, in turn, drive up costs. Gaißert adds that
Märklin also once internally considered the merits of STAMA, another brand in
the CHIRON Group, before deciding against it.
This was because, when compared with STAMA's wheel change concept, CHIRON's pivot holder and chain tool change concept offered advantages with respect to interfering contours. Märklin last purchased a machine in 2014. The machining centers have a service life of around 20 years when operated for two shifts, five days a week.
Modernized production
In the meantime, Märklin's main area of production has
changed again. The Göppingen-based company currently has a total of six
machining centers – three FZ 08 models, two FZ 08 models and one FZ 12 model –
primarily for producing the structural and locomotive housing. The business now
uses industrial motors for its drives. While these are bought in from
elsewhere, they significantly improve the level of detail in the structure and
locomotive housing sections. The experts at Märklin say that this results in
the constant challenge of finding a middle way between what is possible from a
casting perspective or what is only possible with a great deal of effort, and
what can subsequently be achieved more cost-effectively using a machining
center.
»We're now using a fourth generation of machines from CHIRON.
Everything is going very well and our partnership is working perfectly,«
Gaißert explains. He particularly emphasizes the quality of support provided
for process time generation and feasibility studies, adding that test machining
operations are also possible. »Two years ago, we were at CHIRON's premises
because we wanted to try something new – we milled a semi-finished product into
an undercarriage. We first programmed it here and made various attempts, but we
weren't fully satisfied with the outcome,« remembers Sven Dannenmann, Head of
Diecasting and Cast Iron Machining at Märklin. »We then approached CHIRON and
they redesigned the program and produced samples.« Gaißert adds, »At the time,
this production set-up was uncharted territory for us. While we did have a
five-axis machine, we only used it for positioning because we needed to make
holes at suitable angles. For this project, we wanted to mill a solid block
into an undercarriage for the small Z track gage, which was something we'd
never tried before.« Dannenmann continues, »If we are working on a new product
in-house during the design phase and our experienced on-site specialists are
reaching their limits in terms of technical manufacturing, we contact CHIRON
and know that we'll be supported by a skilled partner.«
Bernd Hechler, Technical Consultancy/Sales at CHIRON, states »Development is 100% in Märklin's hands; CHIRON is only brought in if it there are applications where our specialists need support.« As one of the greatest challenges for Märklin is making its products as realistic as possible, the departments involved in development and production are included in order to recognize and resolve any problems at an early stage.
Depending on the part interdependencies, Märklin produces between 80 and 200 housings and attachments a day. The runtimes for each part can vary considerably, depending on the parts' complexity due to their features and details. »Sometimes a part like this can take up to four minutes,« Gaißert explains. »But there are also simple workpieces which can be made in 30 seconds.«
Plans for automation
However,
Märklin has experienced difficulties when it comes to automating its production
facilities. This is primarily because the company machines a wide range parts
and therefore the process of automating the machinery is very complex. »There's
already automation in the form of a brush robot, which machines many – but not
all – of the housings,« says Dannemann, Head of Diecasting and Cast Iron
Machining at Märklin. But ideas are being considered for gradually automating
production. With the assistance of CHIRON, the experts at Märklin are looking
for ways to advance automation in order to further increase the profitability
of its business operations.
Gaißert says that Märklin produces a relatively high number of new products every year – like the current »TEE Edelweiss«, a four-carriage train with all of its attachments made from diecast metal. »Model train collectors expect new innovations at regular intervals. They must all pass through production in a timely manner and on schedule,« states Gaißert. »This entails a great deal of effort in preparation, as the partner parts must interact perfectly and we machine a large number of high-precision items.«
On top of this, the company also produces classic locomotives. »We've still got a lot of molds from the 1950s and 1960s which we continue to use in production today,« Dannemann notes. »These locomotives are known as replicas.« When Märklin releases a new locomotive model, it often also offers the old version at the same time so that collectors have the option of purchasing both. »While the interiors are fitted with brand new technology, the design is the same as the old model's and has all of its characteristics – such as fewer details and attachments,« Gaißert explains. »But that's exactly what makes them so charming and appealing to customers and prospective buyers.« However, just because these models do not have a modern design, this does not mean that they are easier to machine. In fact, they are usually more time-consuming because their mold and tools are technically inferior to modern designs and, therefore, a great deal more manual work is required.
In the medium term, Märklin plans to replace its four-axis FZ 08 W with a five-axis machine. This modernization will increase cost-effectiveness because complete machining will lower the costs for equipment and set-up and also reduce the potential for errors. »Our experience with the five-axis FZ 12 has shown us that this is the right way to go,« says Gaißert. »It would mean that we'd no longer be working with a conventional workpiece changer but instead undertaking complete machining with the five-axis machine. This would also increase flexibility in production.« Each new model brings one-time costs for molds, equipment and tools and you therefore need to find where you can make savings in the process. For smaller batch sizes, complete machining is clearly superior to the workpiece changer setting. Should Märklin ultimately decide to invest in this replacement machine, the machining center will almost certainly be purchased from CHIRON once again.
For more information: www.märklin.de
In KettenWulf's milling shop, different chain plates made from high-tensile, fine-grained steel must be machined in batches of 50 to 1,500 parts. This may not be the preferred number of units for STAMA machines, but STAMA's machining centers appeal because of their speed – in both cutting and assembly.
In addition to speed, there are many other factors that make all the difference for Alexander Opitz, a special machine construction foreman: »The most important criteria for us are dynamics, rigidity, and good service. These requirements were the deciding factors in our latest investment in the MC 338 – reinforced by our positive experience with earlier machines in terms of lifetime and service.«
Groß war die Freude am Fachbereich Maschinenwesen der Fachhochschule (FH) Kiel, als Mitte März zehn Tonnen schwerer Zuwachs in Form der CHIRON FZ 12 MT high speed plus anrollte...
Author: FH Kiel, Joachim Kläschen
Image Description: (From left to right) Professors Rainer Geisler, Alexander Mattes,
Henning Strauß and Daniel Böhnke show how pleased they are with the
ready-to-operate CHIRON machining center.
In mid-March, there was great joy at the arrival of the ten-tonne CHIRON FZ 12 MT high speed plus at the mechanical engineering department of Kiel University of Applied Sciences (FH Kiel). CMS, the retrofitting specialist in the CHIRON Group, had immaculately refurbished the machine and returned it in a virtually new condition. In an ideal world, the team from the Institute for CIM Technology Transfer (CIMTT) headed by Prof. Dr.-Ing. Alexander Mattes would have put the milling-turning machining center into operating straight away. However, their ambitious plans were thwarted by the pandemic. Due to the coronavirus crisis, CHIRON employees were unable to travel to the Kiel University of Applied Sciences to calibrate the new addition.
