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      <title>Trochoidal Overview</title>
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      <div class="title_topic4" id="xps10_pagetitle">Trochoidal Overview</div>
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               <p class="para_td">Overview</p>
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               <p class="para_td"> <a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/trochoidal_ht.html');return(false);">How To</a></p>
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               <p class="para_td"><a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/trochoidal-list_op.html');return(false);">Options</a></p>
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               <p class="para_td"><a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/trocoidal-warn-rt.html');return(false);">Related Topics</a></p>
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      </table><br><p class="para_topic"><b class="uiTerm">Trochoidal</b> is a pattern that cuts using loops to control tool embedding. Use this feature when you need to limit excess stepover to prevent the tool from breaking when it is fully embedded in the cut, and to avoid cutting excess material. &nbsp;You almost always get embedded regions between islands and parts during the engage, in acute internal corners, and in narrow areas. Trochoidal cut eliminates these regions. The cutter machines the material in small looping motions. &nbsp;That is, the cutter spins as it moves in a looping cut pattern. &nbsp;
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      <p class="para_topic"><b class="uiTerm">Outward</b> <b class="uiTerm">Trochoidal</b> is the preferred pattern, and efficiently combines a circular loop and smooth follow movement.
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      <p class="para_topic"><img align="bottom" src="graphics/outward_trochoidal_cut.gif" border="0"></p>
      <p class="para_topic">The example below illustrates <b class="uiTerm">Outward</b> <b class="uiTerm">Trochoidal</b>. &nbsp;Notice the looping cut pattern. &nbsp;Compare this with the conventional method of cutting where the cutter moves forward in a straight path and is surrounded by material on all sides. &nbsp;
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      <div class="title_figure">Trochoidal Cut Pattern</div>
      <div class="title_division">Outward Trochoidal</div>
      <p class="para_division"><b class="uiTerm">Trochoidal</b>, with the cut direction set to <b class="uiTerm">Outward</b>, is the pattern of choice for high speed roughing. This pattern includes trochoidal milling, corner rounding and the additional treatment of corner and embedded areas to ensure a specified stepover. It is a combination of the <b class="uiTerm">Follow Part</b> and <b class="uiTerm">Inward</b> <b class="uiTerm">Trochoidal</b> cut patterns, and is available for Cavity Milling, Planar Milling and Face Milling operations.
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      <p class="para_division"><b class="uiTerm">Outward Trochoidal</b>:
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            <p class="para_item">Prevents tools from slotting or exceeding the specified stepover limit by introducing a trochoidal path.</p>
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            <p class="para_item">Rounds off sharp corners for smooth turns.</p>
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            <p class="para_item">Generally starts away from part walls and progresses towards the part walls.</p>
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            <p class="para_item">Introduces trochoidal cuts only when necessary.</p>
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            <p class="para_item">Provides a variable trochoidal width for machining slots and sharp corners. You specify a minimum width, and the actual trochoidal width is reduced in steps, as required, to avoid gouging. </p>
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                  <td valign="top" align="left"><img align="left" src="../graphics/note.gif" alt="Note" title="Note"></td>
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                        <p class="para_note_body">Note: The <b class="uiTerm">Min Trochoidal Width</b> value must be greater than 0.
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            <p class="para_item"><img align="bottom" src="graphics/out_troch-slot.gif" border="0"></p>
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      <p class="para_division">In a typical pocketing routine, the tool is fully embedded when it first enters a closed cavity or a channel. The tool is also loaded more than intended at the corners. Peaks in the metal removal rate cause early tool failure. This forces machinists to reduce machining parameters and results in lost productivity.</p>
      <p class="para_division">Constant metal removal rate is a very important criterion for high efficiency machining. An optimized trochoidal path ensures the intended metal removal rate is maintained throughout the tool path.</p>
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