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      <title>Boundaries</title>
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      <div class="title_topic3" id="xps10_pagetitle">Boundaries</div>
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      <p class="para_topic">Boundaries define areas that constrain cutting moves. These areas may be defined by either a single boundary that contains the tool or by a combination of boundaries that both contain and exclude the tool. The behavior, usage, and availability of boundaries differ depending on the machining module in which they are used. All boundaries, however, have certain common characteristics regardless of their application.</p>
      <p class="para_topic">The following figure illustrates one of the most common uses of a boundary. A single part boundary in a Planar Mill operation defines the cut volume from which material is removed. The part boundary contains the tool while cutting the part, the floor defines the depth.</p>
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         <p align="center"><img align="bottom" src="graphics/bound_intrfi03.gif"></p>
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      <div class="title_figure">Part Boundary defining Cut Volume</div>
      <p class="para_topic">Check boundaries are used in addition to the specified part geometry (whether the part geometry is defined by boundaries, surface regions, bodies, faces, or curves) to define areas the tool must avoid. In the following figure, check boundaries define holding clamps in a Planar Mill operation.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/bound_intrfi25.gif"></p>
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      <div class="title_figure">Check Boundaries Defining Clamps</div>
      <p class="para_topic">Trim boundaries are used in combination with the specified part geometry to discard or trim away a portion of the cut region. In the following figure, a trim boundary trims away all parts of the cut region outside the trim boundary in a Cavity Mill operation.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/bound_intrfi24.gif"></p>
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      <div class="title_figure">Trim Boundary Restricting Cut Region</div>
      <p class="para_topic">Part and blank boundaries may be used together to define the cut volume. In the following figure, the cut volume is defined by the difference in volumes specified by a single blank boundary and multiple part boundaries.</p>
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         <p align="center"><img align="bottom" src="graphics/bound_intrfi02.gif"></p>
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      <div class="title_figure">Cut Volume Defined by Part and Blank Boundaries</div>
      <p class="para_topic">Drive boundaries are available in Fixed and Variable Surface Contouring when using the Boundary Drive Method or Radial Cut Drive Method. They are used in conjunction with part surfaces to define the cut region. In the Boundary Drive Method, Drive boundaries may exceed the size of the part surfaces, restrict a smaller area within the part surfaces, or coincide with the edges of the part surfaces as illustrated below.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/bound_intrfi23.gif"></p>
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      <div class="title_figure">Drive Boundaries</div>
      <p class="para_topic">In the Boundary Drive Method, Drive boundaries contain the tool for Surface Contouring operations in much the same way as part boundaries do for Planar and Cavity Mill operations. A drive boundary, however, may not fully contain the tool in a variable axis operation. In the following illustration, for example, the side of the tool violates the drive boundary and gouges the part while maintaining a normal tool axis orientation to the part surface. For this reason, drive boundaries should generally be used only for fixed axis operations.</p>
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         <p align="center"><img align="bottom" src="graphics/bound_intrfi22.gif"></p>
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      <div class="title_figure">Drive Boundary Violated</div>
      <p class="para_topic">In the Radial Cut Drive Method, boundaries enables you to generate drive paths perpendicular to and along the boundary as illustrated below.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/bound_intrfi21.gif"></p>
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      <div class="title_figure">Drive Boundary</div>
      <p class="para_topic">Curves, edges, and points used to create boundaries need not be planar (faces must be planar). The resulting boundaries, however, are always planar. The selected geometry projects to the Boundary Plane along a vector normal to the Boundary Plane as illustrated below.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/bound_creafi06.gif"></p>
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      <div class="title_figure">Nonplanar Edges</div>
      <p class="para_topic">Selected curves and edges need not be contiguous to form a closed boundary. In the following figure, the selected edges are not connected. After projecting to the Boundary Plane, the boundary members lengthen and shorten where necessary to form a planar closed boundary (provided Type is specified as Closed).</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/bound_intrfi19.gif"></p>
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      <div class="title_figure">Noncontiguous Edges</div>
      <p class="para_topic">The Boundary Plane may either be user defined or system defined. When system defined, the first two selected curves or the first three defined points establish the Boundary Plane. If the system cannot define a plane using the selected curves or edges, the Boundary Plane is created on the XC-YC plane.</p>
      <p class="para_topic">Automatic Plane is very useful in establishing the ZC level when selecting planar curves that are parallel to the XC-YC plane.</p>
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            <td valign="top" align="left"><img align="left" src="../graphics/note.gif" alt="Note" title="Note"></td>
            <td valign="bottom" align="left" width="100%">
               <div class="para_note">
                  <p class="para_note_body"> When selecting contoured 3d curves or edges, if a specific boundary plane is desired (such as the XC-YC plane), the user-defined boundary plane should be used. Using Automatic with 3d curves can lead to unexpected results and is not recommended.</p>
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      <p class="para_topic">In Lathe operations, boundaries do not project along a vector to define a volume. Instead, they define a planar cross-section of material to be removed.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/bound_intrfi18.gif"></p>
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      <div class="title_figure">Lathe Rough Boundaries</div>
      <p class="para_topic">Boundaries consist of members. Each member is a segment containing attributed information such as Intol/Outtol, Side Stock, and Tool Position. Individual members are easily identified by their tool position indicators.</p>
      <p class="para_topic">All boundaries have certain common characteristics which include a Start Point, Tool Position (on, tanto, contact), Direction, Material Side (inside/outside, left/right), and Type (open or closed). Each of these characteristics is described below.</p>
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