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      <title>Zig With Contour</title>
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      <div class="title_topic3" id="xps10_pagetitle">Zig With Contour</div>
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      <p class="para_topic">Zig With Contour creates a Zig cut pattern that follows the contours of the cut region between consecutive Zig passes. It rigorously maintains a Climb or Conventional cut. The tool path is defined as either Climb or Conventional based on the first Zig pass along the edge of the cut region.</p>
      <p class="para_topic">The following figure illustrates the basic sequence of Zig With Contour tool movements for a Climb cut.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/pcmill_figurespl43.gif"></p>
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      <div class="title_figure">Zig With Contour - Climb</div>
      <p class="para_topic">Each of the above tool movements are listed in sequence and described below.</p>
      <ol type="1" start="1">
         <li>
            <p class="para_item">Initial Engage avoids engaging directly into a pocket corner or along wall.</p>
         </li>
         <li>
            <p class="para_item">Initial Stepover</p>
         </li>
         <li>
            <p class="para_item">Initial cutting pass cuts in the opposite direction of the remaining Zig passes. This pass defines the operation as Climb or Conventional.</p>
         </li>
         <li>
            <p class="para_item">Stepover</p>
         </li>
         <li>
            <p class="para_item">First zig pass</p>
         </li>
         <li>
            <p class="para_item">Retract</p>
         </li>
         <li>
            <p class="para_item">Traversal</p>
         </li>
         <li>
            <p class="para_item">Engage</p>
         </li>
         <li>
            <p class="para_item">Stepover</p>
         </li>
         <li>
            <p class="para_item">Second Zig Pass</p>
         </li>
         <li>
            <p class="para_item">Stepover</p>
         </li>
      </ol>
      <p class="para_topic">The sequence of tool movements 6 through 11 continue to repeat.</p>
      <p class="para_topic">Zig With Contour cuts in a series of &quot;loops&quot; as illustrated below. The first loop has four sides, while all subsequent loops have only three sides.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/pcmill_figurespl42.gif"></p>
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      <div class="title_figure">Zig With Contour Loops</div>
      <p class="para_topic">The tool engages at the end of the bottom of the first loop. In the above example, this position is at the bottom right corner of the first loop. By doing this, the tool engages into the material to be removed and avoids engaging directly into the corner of a cavity or along a wall, producing a cleaner cut. The system defines the bottom side of each loop by the general direction in which the tool moves across the part as it progresses from one loop to the next. The tool progresses in a general direction from top to bottom of each loop.</p>
      <p class="para_topic">Once the first loop has been completed, the tool traverses to the beginning of the second loop. Because the bottom of the first loop corresponds to the top of the second loop, the second loop has only three remaining sides left to cut. The system therefore engages the second loop (in the above example) at the beginning of the left side. This pattern continues to repeat for subsequent loops.</p>
      <p class="para_topic">By understanding how Zig With Contour cuts in a series of loops, it becomes apparent why the first pass cuts in the opposite direction of the remaining Zig passes. The first pass is at the top of the loop while the subsequent passes are at the bottom of the loops.</p>
      <p class="para_topic">Stepovers are cutting moves and follow the cut region contours as illustrated below. Zig passes also follow cut region contours provided the contours do not cause the passes to intersect.</p>
      <p class="para_topic">Because all moves are cutting, the system does not recognize this cut type as having stepovers when you assign feed rates. The assigned cut feed rate therefore affects all cutting moves including stepovers.</p>
      <p class="para_topic">In cases where Zig passes cannot follow cut region contours because of intersecting passes, the system generates a sequence of shorter passes and traverses between subregions as illustrated below.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/pcmill_figurespl41.gif"></p>
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      <div class="title_figure">Zig With Contour - Climb</div>
      <p class="para_topic">Wall Cleanup should be turned on when using the Follow Periphery, Zig, and Zig-Zag cut patterns. This assures that excess material will not be left along the wall of the part, which could leave too much material for the tool at the next cut level.</p>
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