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Suburban Building Studios slashed the
time required to produce detailed architectural models from several
weeks to one day by switching from hand modeling to a CNC router.
The CNC router, which costs only a fraction of the price of laser
cutting machines also provides far better accuracy and detailing
than could be achieved by hand. The use of CNC routing has
dramatically improved the competitive position of the company by
allowing it to produce higher quality models at a lower cost than
its competitors.
Suburban Building Studios has been in
the business of producing architectural models for about 10 years.
For most of that time, the company has used traditional manual
modeling techniques. Over the past several years, management has
grown concerned about the amount of time required by this approach.
About a year ago, the company began to investigate automated methods
of producing architectural models.
The company first considered laser
cutting machines which have been installed by a number of architects
and larger modeling firms. These machines operate from a CNC program
that is usually created by translating the CAD model creating during
the design process. They provide a very high level of accuracy and
can produce a model that is as detailed as the original CAD model.
The problem is that these machines are quite expensive. A model with
a four foot by four foot working surface, required to handle many
larger modeling jobs, costs in the area of $100,000. The least
expensive laser machines cost about $25,000 but provide only a 12
inch by 18 inch working surface. Another problem with these machines
is that they are capable of taking only very light cuts.
Then, management heard about a computer
controlled router that performs a similar function at a fraction of
the price. The 3-axis gantry router from Techno, Inc., New Hyde
Park, New York, generates an extremely accurate model based on a CAD
program and provides a 4- foot by 4-foot work surface for only about
$17,000. This is less than one-fifth the price of a laser cutter
capable of handling the same size work piece. The router is also
capable of taking much heavier cuts than a laser cutter. For
example, it can easily cut ¾ inch plywood while depth of cut for a
laser cutter is typically limited to about ¼ inch. |
The accuracy of the router is about the
same as the laser cutter and far superior to manual methods. The
Techno system has an accuracy of +.1 mm (+0.004) in 300 mm and a
repeatability of +0.01 mm (+0.0004). Techno routers have
anti-backlash ball screws for play-free motion that makes it
possible to produce accurate circles and inlays. These ball screws
also make it possible to produce extremely accurate wooden or
plastic parts. The ball screws have excellent power transmission due
to the rolling ball contact between the nut and screws. This type of
contact also ensures low friction, low wear and long life.
A typical project on which Suburban
Building Studios used the new CNC router approach is an existing
primary school in New York City which was modeled to assist in a
renovation and addition project. The existing building was built in
the neoclassical style and contained a significant amount of
detailing including windows, mullions, modulating brickwork,
capstones and door openings, which the architects wanted to include
in the model. The elevation of the building, which is 100 feet wide
by 40 feet tall, was modeled at a scale of 1/8 inch to 1 foot.
Producing a hand model of the primary school would have taken
several weeks and it would have been very difficult to achieve the
level of detail and accuracy that the architects required.
While architects typically supply CAD
models of their projects, in this case Suburban Building Studios was
asked to produce the model. The company used Mastercam CNC
programming software from CNC Software, Tolland, Connecticut, which
comes with the machine. While the machine is capable of full 3D
contouring, the Suburban Building Studios modeler felt that the
elevation was best suited to a multiple layer 2D model. He started
by creating a 2D elevation drawing of the structure. Then he copied
the drawing 11 times to different layers designed to represent depth
in the elevation. For each layer, the modeler deleted the details
that did not appear at the appropriate depth. For example, one layer
focused entirely on the window mullions while several others
emphasized the brick and stone work.
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The layers were then combined into a CNC
machining program. Each layers represented one pass of the cutting
tool with the depth of cut equal to the layer spacing on the actual
building when reduced to scale. A high level of detailing accuracy
was achieved by using a 0.02 inch diameter cutter. Depth of cut
ranged from 1/16 to 1/64 inch.
Once the program was finished, a piece
of monochromatic grey plastic board was simply loaded into the
machine and a few buttons were pushed to start it up. The modeler
was then able to walk away while the machine finished the part. The
entire process of creating the CAD model, converting to a CNC
program and machining the model took just one day. The finished
model had far more detail than could ever have been achieved in a
hand model.
Suburban Building Studios has found many
other applications for the router. It uses CNC techniques to produce
architectural competition boards that stand out because the design
is engraved right into the boards. It has created full-scale
components for design projects such as some special clips used in
the Michael Jackson kiosk at the Sony Building in New York City. It
has also built some equipment for its own use such as an
architectural easel.
In one year of operation, Suburban
Building Studios has never had any problems with the machine. This
is partly due to the strength and rigidity of the table. The Techno
machine is constructed from extruded aluminum profiles that can
support all architectural modeling materials and provides easy
clamping capability. The machine also has four ground and hardened
steel shafts and eight re-circulating bearings in each axis. This
shaft and bearing system produces very smooth play-free motion and
an extremely rigid system that produces high quality cuts.
All in all, the new router has helped
Suburban Building Studios dramatically improve its competitive
position. The company has much lower cost and higher quality
relative to modeling studios and architectural firms that build
models by hand. It is also in a strong position relative to larger
firms using laser cutting machines because the machine it used is so
much less expensive and easier to use. |
