CPT International 4/2019

3-D-PRINTING
lerate the curing process of the binder.
After that taskthe building platform is
lowered by another layer of 300 µm
and the process starts over and is repeated
until the mold is fully constructed.
“Binder jetting is the only proven and
economical process for the automated
production of sand-casting molds,” explains
Hülsmann. After printing, an
employee extracts the finished molds
and removes excess silica sand with
compressed air or a brush. Instead of
giving the printed molds to foundries,
which would again consume time, Lütgemeier
GmbH casts not only lightweight
alloys such as aluminium but
also highly heat-resistant steels themselves
in-house. In addition, the automotive
specialist can also carry out the
complete post-processing of the components
directly. Several 5-axis milling
machines as well as lathes and several
measuring devices are available. Lütgemeier
GmbH is thus able to produce
Up to quality assurance
Lütgemeier
can map all essential
steps of the value
chain in-house.
optimized components without lengthening
the supply chain by making
intermediate stops.
The efficiency of this process optimization
can be seen in a practical
example. Brabus has specialized in the
refinement of Mercedes Benz automobiles
for over 40 years. Among others,
Brabus created the Brabus G900 based
on the Mercedes AMG G 65. The built-in
V12 twin turbo engine delivers an incredible
900 hp and accelerates the car to
100 km/h in just 3.9 seconds. That is
supercar performance in an off-road
vehicle. This is possible through the
optimisation of the engine’s performance.
Tailor madeturbochargers with
enlarged compressor housings from Lütgemeier
contribute to this enormous
increase in performance.
60% time saving in the
production of complex sandcasting
molds
Hülsmann is convinced of the investment
in the 3-D printing system. After
all, the time saved is significant.
“Thanks to the printing system and the
comprehensive “in-house” post-processing
including quality assurance measures,
we can achieve a time saving of up
to 60 percent when manufacturing
complex and qualitatively high-grade
sand-casting molds”, says Hülsmann.
Automation provides both increased
flexibility and productivity and, ultimately,
high levels of customer satisfaction,
with components available more
quickly and better than ever before
„The finished cast parts are available
faster and we can invest more time in
the post-processing and optimization of
individual components, depending on
the customer‘s requirements. Or simply
deliver faster,“ continues Hülsmann.
An advantage that has gone down
well with Brabus: “It is extremely time
and cost intensive to increase the performance
of an engine. The goal is to
optimize the engine to maximum performance
in a limited motor compartment.
This is why 3-D printing is the
perfect solution. Through the layer-bylayer
construction, we can design geometries
and components which could
not be produced using conventional
methods,” says Jörn Gander, Director of
Technology and Development at Brabus.
„The collaboration with Lütgemeier
is characterized above all by the
fast delivery of quality-assured and
optimized components. We save on
post-processing and can install the
parts immediately. This is decisive for
our development as well as assembly
and gives us an advantage over our
competitors“.
An additional benefit: The costs of
producing sand-casting molds are
reduced. “For complex components up
to a certain batch size, 3-D printing is
always more favourable compared to
conventional approaches due to the
lack of tooling costs,” says Matthias
Steinbusch, Sales Manager at voxeljet.
“The smaller the batch size, the greater
the cost benefit of using the voxeljet
technology”. This also plays into the
hands of Brabus. The G900 model is
only available 10 times in this world. A
batch size in which 3-D printing guarantees
maximum efficiency in production.
The compressor housing from Lütgemeier for the Brabus G900.
300 dpi resolution: 3-D printing
enables filigree geometries
Phenolic Direct Binding also enables
new design possibilities. „The freedom
of design is far less restricted than with
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