Indispensable shift workers - fmb-machinery.de

Indispensable shift workers
Carl Zeiss Jena GmbH automates four CHIRON machining centers with FMB robots
A successful baptism
of fire: permanently
installed Unirobots
load four Chiron
machining centers in
three-shift working at
Carl Zeiss in Jena.
The workpieces are
filigree, closely
toleranced and must
be inserted in and
removed from the
special jigs with
absolute precision.
The rationalization
effect is so
substantial that
further applications
of this kind are being
planned. (All pictures
by: FMB/Hennecke)
For welding, riveting, bonding, painting, assembling, palletizing... robots are
used throughout the world in a hundred thousand different ways as a proven
means for individual rationalization purposes. As if costs only have to be
reduced in this area. And so it is surprising to many that the tireless laborers
play a rather subordinate role in the automation of machine tools. Or rather
played, because the FMB Maschinenbaugesellschaft in Faulbach now offers the
Unirobot, a universally adaptable automation solution based on a six-axis
articulated-arm robot. The first four applications brilliantly passed their baptism
of fire at Carl Zeiss in Jena some time ago. Four Chiron machining centers
(modified for the precision machining of highly filigree, closely toleranced lens
housing components) have been loaded and unloaded there fully automatically
for more than a year - in 3 shifts on 355 days a year.
The market for digital projectors is booming, something which naturally pleases Dietmar
Bauer, head of mechanical systems/surfaces in the production service center at Carl
Zeiss in Jena, because "optical engines from our company are the 1st choice, especially
for manufacturers of high-grade PC projectors". One thing is clear: especially in
globalized market segments, top products secure the future of the local production site,
and therefore jobs. Of course, technical refinements and the highest manufacturing
quality are useful, but have not been the sole factor in international competition for a
long time. Bauer: "We are the company supplier of mechanical component parts and job
lots for the mechanical/optical devices of Carl Zeiss Jena GmbH, but we have also been in
competition with external companies for a long time. We have to prove our qualification
once more at every product change."

Especially in the case of high volumes - this means
quantities of more than 100,000 per annum (for the
time being) of the mechanical lens components
currently being manufactured - Asian competitors are
exerting powerful pressure. The battle is mainly over
price. Any manufacturer who is qualified to
manufacture these lens components, which are
extremely demanding with regard to production
technology - i.e. they can offer quality, quantity, a
competitive price and deliver to schedule - has good
prospects for steadily growing volumes.
However, cost-effective production capacities with
high throughput had to be developed first of all to
secure the in-house production of lens sleeves and
lens adjustment rings. This about two years ago and
was "not at all easy" as Christina Schmoginski, who is
responsible for technology projects at Carl Zeiss in
Jena, discovered. She explains: "The components
don't look very spectacular, but they are anything but
easy to manufacture in series. Production necessitates
various turning and milling operations and, with a
cutting proportion of up to 97%, the workpieces are
very thin-walled at the end and thus extremely
difficult to clamp." Precise clamping is very important,
however. The tolerances for concentricity and groove
widths must be within a tolerance range of around 10
µm, so that the finished objectives focus smoothly and
without play under all operating conditions. Accuracies
within the IT 6 range are required for the large
number of tolerances on fit. Schmoginski continues:
"We examined a great variety of production methods
and production facilities but even start-to-finish
machining on our existing turning/milling centers did
not provide acceptable results."
Finally, it became clear that manufacturing from a
block could only be done in two stages, i.e. first
turning and then milling. Five indexes (G 200 and G
300) were decided on for the turning jobs. Four Chiron
machining centers (FZ 08 and FZ 12 W) equipped with
a precision rotary table as well as special clamping
facilities were chosen for the milling tasks. Although
this infrastructure meant that the Thuringia-based
company now had the production technology under
control, the unit costs were still too high, especially for
milling. Karl-Heinz Vlay, head of production scheduling
and engineering services, explains: "We have cycle
times for the milling of up to five minutes per
workpiece. Consequently, there is a great deal of
downtime for operators, even with multiple machine
assignment. In addition, there is the fact that we want
to utilize the capacities to the full with three shifts." If
vacation and sickness periods are included, the
smooth use of the four machining centers would have
required at least five to six employees. The human
performance curve, fitness for work and working
morale also do not always orient themselves towards
Dietmar Bauer, head of
mechanical
systems/surfaces, Carl
Zeiss Jena GmbH,
production service center:
"... we have also been in
competition with external
companies for a long
time. We have to prove
our qualification at every
product change."..."
Karl-Heinz Vlay, head of
production scheduling and
engineering services, Carl
Zeiss Jena GmbH,
production service
center:"...there is a great
deal of downtime even
with multiple machine
assignment. In addition,
there is the fact that we
want to make full use of
the capacities with three
shifts..."

production schedules, so an automation solution had
to be found. The next problem.
Dietmar Bauer: "We inquired at various vendors. All of
them backed out, at the latest when the subject of the
particular requirements for the clamping of the
workpieces came up. Nobody wanted to guarantee
that the requisite positioning accuracies could be
reliably met. Furthermore, the linear systems offered
were highly inflexible and are also very expensive. The
suppliers of robots are probably working to full
capacity with other automation tasks. At least, nobody
wanted to take a risk with an application with a
machining center."
Shortly before frustration could set in, assistance
came in the shape of André Ochmann, a sales and
marketing partner of the FMB
Maschinenbaugesellschaft, who is active in east
Germany. His proposed solution: the new FMB
Unirobot.
To put it succinctly: the FMB solution based on a sixaxis
articulated-arm robot was also more or less a
prototype at that time. References: zero!
Nevertheless, FMB was given the opportunity and took
full advantage of it. Ochmann not only guaranteed the
people responsible for investment that the required
positioning accuracy for the position-orientated
insertion of the four different workpieces into the
respective special jigs of the machining center would
be achieved, he was also able to put forward this
argument as a confidence-building measure: "FMB has
approximately 15,000 loading magazines in the field.
As a result, we have comprehensive know-how in the
field of mechanical interfaces and the control and
software engineering adaptation of automation
systems and machine control systems." Confidence at
FMB was so high that the Faulbach-based company
agreed to take back the system free of charge if it
failed. Another sound argument for the Unirobot for
Dietmar Bauer was that FMB approached the project
from top to bottom with a commitment which "had
previously not been shown by other suppliers. The
support over the entire project was exemplary.
Nikolaus Dobrov, the responsible design engineer, was
even available to us on the spot for three days during
commissioning." This is nothing unusual for Dobrov,
however: "It only means extra work and annoyance if
we leave a construction site behind us. There are
always teething troubles with such projects. That's
why it's normal at FMB to have somebody there during
the running-in phase who knows the details.
Furthermore, we also made intensive use of the three
days for training and practice." Whereby, according to
Dobrov, the handling and above all the programming
of the FMB Unirobot "can be learned very quickly. The
robots are programmed using the teach-in method.
Christina Schmoginski,
technology projects, Carl
Zeiss Jena GmbH,
production service center:
"... they are anything but
easy to manufacture in
series... even our existing
turning/milling centers did
not provide acceptable
results."
Nikolaus Dobrov, design
department, FMB
Maschinenbaugesellschaft,
Faulbach: "Teething
troubles are perfectly
normal with such
projects. That's why it
makes good sense to
have somebody there..."

Any CNC programmer with standard skills can quickly
master this and easily create the desired control
programs." In short: the robots and machining centers
very quickly reached agreement on productive
teamwork at Carl Zeiss in Jena.
Since the turn of the year 2000/2001, the four Chiron
machining centers have been producing four different
workpieces in three shifts. And after meanwhile more
than a year of continuous operation, the Unirobots are
considered to have passed their baptism of fire with
flying colors. Praise from Dietmar Bauer: "We used the
installations to full capacity around the clock for 355
days in the first year. There were also some
standstills, of course, but they were mostly down to
the machining centers. The robots and the palletizers
work very reliably. The entire automation rarely
causes problems."
Something which naturally also has the consequence
of contributing to a speedy amortization of the total of
around 300,000 euros paid to FMB. Dietmar Bauer has
no doubt that the investment will quickly pay for itself:
"The capacity of the adapted workpiece magazines is
large enough for a complete shift. We therefore
produce to a large extent without personnel and at a
consistently high quality." When compared with the
labor costs for a correspondingly productive team of
machine loaders and unloaders, a return on
investment within a year is totally realistic. Although
Dietmar Bauer does not provide any precise figures in
this regard, his next statement speaks volumes: "If we
hadn't taken this step, we wouldn't have had the
orders in-house any more!"
And the pressure on production service providers - no
matter whether they are part of the concern or
freelance - will probably increase even more in future.
The Asians are not needed for this. For example, the
enlargement of the EU to the east has been politically
decided on and will be a fact in a few years. It will
probably be one to two decades before the economic,
fiscal, social and environmentally relevant basic
conditions between the western and eastern EU put
the possibilities for the estimate of job order costs on
an equal footing. This is probably also the reason, but
not the only one, why André Ochmann firmly believes
that FMB customers will not only successfully reduce
their costs with bar loaders in future, but also that
"the FMB robot automation will open up new potentials
for increased efficiency for a great many metalworking
companies."
André Ochmann, dealer in
machine accessories and
automation technology,
Nißma: "...comprehensive
know-how in the field of
mechanical interfaces and
control and software
engineering adaptation..."

The concept of the FMB Unirobots is as promising
as it sounds. The FMB robots can be permanently
installed on a single machine - as at Carl Zeiss
Jena GmbH - or the Unirobots can also be
connected and used as a mobile automation unit
for demand-oriented use, e.g. on CNC lathes,
with a few movements of the hand. The costs for
interface and door opening mechanism are oneoff
investments and will soon pay dividends, as
they say. The prices for the Unirobot start at
approx. 42,000 euros. Optional auxiliary
equipment, such as task-optimized pallet
systems and workpiece grippers, is also
available. The grippers are available in two- or
three-jaw execution. The utilization of a variety
of base plates ensures optimum gripper
arrangement at all times. The gripper is changed
with a few movements of the hand and FMB also
supplies tailored executions for special
requirements. In order that the Unirobot can
quickly move from machine to machine without
complications and to ensure fast access to the
working area of the machine tool when required,
the work safety cage with an integrated
automatic door opening system can be relatively
easily traversed, even with restricted space
conditions. The footprint measures 1,100 mm
square, the height is 1,800 mm and the
complete solution weighs about 350 kg. FMB has
implemented a reasonably priced and easy-toconvert
standard interface for the mechanical
and electrical coupling of robot and CNC
machine. The operator's panel of the Unirobot is
detachable and with a weight of 1 kg is
extremely manageable. The program parameters
and program sequence are visualized by means
of a high-quality TFT color display.
Guaranteed precision in series: The
tolerances for concentricity and
groove widths of the mechanical lens
components must be below 10 µm,
IT 6 is required for the large number
of tolerances on fit. Measurement
directly after milling guarantees
short paths and a quick reaction in
the case of any deviations.
Ochmann continues: "I am confident that we can open up further interesting fields of
application very quickly with our robot handling system. We are processing several
orders at the moment, and there are a large number of definite projects in progress. For
example, we are automating a grinding machine for a new customer at the moment."
Consequently, the only restriction is the given technical data of the FMB Unirobot. This
specifies a working range of 515 mm and maximum workpiece weights of 2 x 2.5 kg.
Naturally, there are still alternatives if required, because although the robot is important,
it is replaceable in principle. What is fundamental is that such applications always
function reliably and the supplier first and foremost has a good knowledge of interfaces
for hardware and software and of mechanical engineering. Ochmann says: "In this
connection, FMB has know-how at its disposal which has been developed over a period of
time."

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All inclusive: While the Chiron
machining center, which is
equipped with a changeover table,
cuts chips, the FMB Unirobot loads
and unloads and deburrs the
filigree lens adjustment rings
outside the machine time. The
silent attendants also clean the
special clamping jigs before each
new load (not shown here).
Perfection in automation: FMB
magazines with rolling holding
cassettes adapted for the supply of
workpieces and storage of the lens
rings. The stock of workpieces and
the storage capacity for the
finished parts are sufficient for one
shift.