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      <title>Use control points</title>
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      <div class="title_topic3" id="xps10_pagetitle">Use control points</div>
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               <p class="para_td"><a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/plunge_mill_ov.html');return(false);">Overview</a></p>
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               <p class="para_td"><a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/plunge_list_op.html');return(false);">Options</a> 
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      </table><br><div class="title_division">Pre-Drill Points</div>
      <p class="para_division">There are two ways to use pre-drill points. You can manually specify a pre-drill point, or you can have the system generate pre-drill points for you. To automatically generate pre-drill points:</p>
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            <p class="para_item">Create and generate the plunge milling operation. </p>
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            <p class="para_item">Create and generate a drilling operation.</p>
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            <p class="para_item">Reorder the drilling operation to put it before the milling operation. </p>
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      <p class="para_division">To manually specify pre-drill engage points, click <b class="uiTerm">Points</b> and <b class="uiTerm">Edit</b> in the <b class="uiTerm">Pre-Drill Engage Points</b> section of the <b class="uiTerm">Control Geometry</b> dialog box. You may then specify the depth of the hole and specify the points.
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      <p class="para_division">When you specify a pre-drill point, the system assumes that the hole is big enough for a non-center-cutting tool to plunge. The first plunge is then made at the pre-drill point, and the following plunges proceed towards the pattern start point.</p>
      <p class="para_division">Drill points are used for all closed cavities. For open cavities, if the pattern start point is closer to the open area than the drill point, the drill point is ignored.</p>
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      <div class="title_figure">Pre-drill point (A)</div>
      <p class="para_division">Closed cavities usually require a pre-drill point for non-center cutting tools.</p>
      <p class="para_division">If NX can't start to cut a closed cavity without violating the maximum cut width, it will still cut the cavity, but will also output a pre-drill point and a warning message. Use the pre-drill location, or specify another point, to add a drilling operation before the plunge milling operation. .</p>
      <div class="title_division">Start Points</div>
      <p class="para_division">Pattern start points are the same as in cavity milling. When drill point locations and pattern start point locations conflict, the same rules are followed as for cavity milling.</p>
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