CREATING THE SECOND COMPONENT PART: THE T JUNCTION
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Now, an intersection composed of two pipe sections will be created in a separate
file and the surfaces will be trimmed. Then this file will be imported to the
original model to create the entire piece.
Creating one of the pipe sections
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Choose Files
New , thus starting
work in a new file.
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Choose Geometry
Create
Point
and enter points (0, 9) and (0, 11). Press ESC to conclude the
creation of points.
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From the Copy window, select Points and Rotation . Enter
an angle of 180 degrees and from the Do extrude menu, select Lines
. The axis of rotation is the x axis. Enter two points defining the axis, one
in First Point and the other in Second Point , for example, (0,
0, 0) and (100, 0, 0) (Figure 22).
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Click Select and select the two points just created.
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Repeat the process, this time entering an angle of –180 degrees, thus creating
the profile of the pipe section with a second rotation of 180 degrees. The
rotation could have been carried out in only one rotation of 360 degrees.
However, in the present example, each circumference must be defined between two
points (Figure 23).
Figure 22. The
result of the first180-degree rotation
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Figure 23. The
combined result of the first rotation and the second rotation of 180 degrees,
thus obtaining the profile of the pipe section.
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From the Copy window, choose Lines and Translation . In First
Point and Second Point , enter the points defining the
translation vector. Since the pipe section must measure 40 length units, the
vector is defined by points (0, 0, 0) and (-40, 0, 0).
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From the Do extrude menu, choose the Surfaces option.
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Click Select to select the lines that define the cross-section of the
pipe. Press ESC to conclude the selection process.
Figure 24.
Creating a pipe by extruding circumferences
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Creating the other pipe section
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Choose Geometry
Create
Point
and enter points (-20, 9) and (-20, 11). Press ESC to conclude the
creation of points.
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From the Copy window, select Points and Rotation . Enter
an angle of 180 degrees and from the Do extrude menu, select Lines
. Since the rotation can be done on the xy plane, choose Two Dimensions
. The center of rotation is the coordinates (-20, 0, 0).
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Click Select and select the two points just created. Repeat the process,
this time entering an angle of -180 degrees.
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From the Copy window, select Lines and Translation . In First
Point and Second Point enter the points defining the translation
vector. Since this pipe section must also measure 40 length units, the vector
is defined by points (0, 0, 0) and (0, 0, 40).
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From the Do extrude menu, select the Surfaces option.
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Click Select to select the lines that define the cross-section of the
second pipe. Press ESC to conclude the selection.
Figure 25. A
rendering of the two intersecting pipes
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Creating the lines of intersection
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Choose Geometry
Edit
Intersection
Surface-surface
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Select the outer surfaces of each pipe, thus forming the intersection of the
two surfaces selected.
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Repeat the process to obtain the four lines of intersection.
Figure 26.
Creating lines of intersection between the surfaces
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Deleting surfaces and lines
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Choose Geometry
Delete
Surfaces
and select the small surfaces inside the first pipe. Press ESC to
conclude the process of selection.
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Choose Geometry
Delete
Lines
. Select the lines defining the end of the second pipe (foreground) that are
still inside the first pipe (background). The result is shown in Figure 27.
Figure 27. Final
configuration after deleting surfaces and lines
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The model now has three outlets. The two farthest from the origin of
coordinates must be closed. The third will be connected to the rest of the
piece when the T junction is imported.
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Choose Geometry
Create
NURBS
Surface
By contour and then
select the lines defining the outlet in the foreground of Figure 28. Press ESC
(see Figure 28).
Figure 28.
Creating a NURBS surface to close the outlet in the foreground
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Repeat the process for the other outlet to be closed.
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From the Files menu, select Save to save the file. Enter a name
for the file and click Save .