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Introducing the Objet 3D Printing System
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DOC-06800 Rev. A
Source Files
Objet 3D printing systems produce three dimensional models designed
with most 3D CAD tools and with other job specific 3D applications. Objet
systems accept:
•
STL Files
•
SLC Files
Objet systems feature the capability of producing both types of model files
simultaneously.
STL Files
STL is short for Standard Triangulation Language . This language views any
object as a collection of surfaces, and describes each surface of the object as
a collection of triangles.
For example, a square can be described as two triangles; a cube (six
squares) as 12 triangles. Curved surfaces need more triangles to describe
them. The higher the tolerance (for smooth surfaces), the more triangles are
needed. The result is that high quality object descriptions mean very heavy
files.
Most CAD software can export STL files. The Objet system utilizes these
files for building models (rapid prototyping), and also for directly making
molds for mass producing items.
STL files can be ASCII (text) files or binary files. The content of the ASCII
file begins with “solid” and ends with “end solid” (both lower case).
Between these keywords is a list of the triangles that describes the faces of
the solid model. Each triangle defines a single normal vector directed away
from the solid’s surface, followed by its X Y Z coordinates. These are
expressed as Cartesian coordinates and are floating point values. The
coordinates of all triangles should be positive and should fall within the
volume of the model.
SLC Files SLC is short for Stereo Lithography Contour . SLC files describe two
dimensional contours of the three dimensional models. These contour lines
are polylines.
SLC files are ASCII (text) files that save models as a series of slices. This
means that models based on SLC files cannot be orientated; only their scale
(size) and position on the build tray can be controlled. For this reason, the
model’s orientation must be suitable for production before it is saved as an
SLC file. Because of the nature of SLC files, the appearance of models in
Objet Studio may be different than the solid object images displayed from
STL files.
D R A F T
16 June 2013