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      <title>Temporary vs. Permanant</title>
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      <div class="title_topic3" id="xps10_pagetitle">Temporary vs. Permanant</div>
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      <p class="para_topic">A boundary may be either temporary or permanent. Permanent boundaries are created outside the machining modules using the Toolbox&gt;Boundary option or within the machining modules using the Create Permanent Boundary option in the Edit Boundary dialog box. Once created, permanent boundaries continually display on the screen like any other permanent geometric entity (line, arc, etc.) and can be used in any machining module requiring the use of boundaries.</p>
      <p class="para_topic">Temporary boundaries are created within the machining modules from options available within a main dialog box as illustrated below. They are displayed as temporary entities and will disappear whenever the screen is refreshed. Temporary boundaries can be redisplayed at any time using the boundary Display option.</p>
      <p class="para_topic">The advantage of creating permanent boundaries is that they are created just once and can be reused in many operations. Permanent boundaries prevent you from having to select the same geometry again and again. This makes them especially useful for defining boundaries from complex surface edges as illustrated below.</p>
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         <p align="center"><img align="bottom" src="graphics/bound_intrfi06.gif"></p>
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      <div class="title_figure">Complex Edges</div>
      <p class="para_topic">Permanent boundaries, however, are nonassociative to the parent geometry and can only be created by selecting curves and edges. Once created, they cannot be edited.</p>
      <p class="para_topic">Temporary boundaries have many advantages. They can be created from curves, edges, existing permanent boundaries, planar faces, and points. They are associative to the parent geometry, can be edited, and can be customized with Intol/Outtol values, Stocks, and Cut Feedrates. In addition, temporary boundaries can easily be used to create permanent boundaries.</p>
      <p class="para_topic">The temporary boundary in the following figure was created by selecting a single planar face. A permanent boundary could then be created by simply selecting the option Create Permanent Boundary. Creating this boundary initially as a permanent boundary would prove difficult because you would be required to select all of the edges of the face individually.</p>
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         <p align="center"><img align="bottom" src="graphics/bound_intrfi05.gif"></p>
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      <div class="title_figure">Single Planar Face</div>
      <p class="para_topic">When you select a permanent boundary to define geometry in an operation, the system creates a copy in the form of a temporary boundary. This copy can then be edited just like any other temporary boundary.</p>
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