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      <title>Trim Relief</title>
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      <div class="title_topic4" id="xps10_pagetitle">Trim Relief</div>
      <hr noshade="true">
      <div class="title_division">Description</div>
      <p class="para_division">A DFM feature on both sides of a flange breakline. It is a notch located where the flange break line, and the trim line intersect.</p>
      <div class="title_division">Purpose</div>
      <p class="para_division">To ensure that an adequate notch at the end points of a flange breakline is present and constructed correctly to reduce the possibility of metal splitting during the flanging operation. Consider the picture below. The flange in the picture has one correct trim relief, and the other is incorrect. The incorrect trim relief does not have the correct offset distance, and the trim radii are too small.</p>
      <p align="center"><img align="bottom" src="graphics/dfm_trim_relief_iso.gif"></p>
      <div class="title_division">Computational Method</div>
      <div class="title_division">Checking Start Angle (computed first)</div>
      <p class="para_division">The angle the trimming curve makes with breakline must be greater than Minimum Start Angle value(? ). See the picture below.</p>
      <p align="center"><img align="bottom" src="graphics/dfm_trim_relief_angle.gif"></p>
      <div class="title_division">Measuring Offset Distance (computed second)</div>
      <p class="para_division">The offset distance is measured in the plane normal to the trimming direction. First the tangent from the breakline tangent is projected into the trimming view. Secondly, the trimming curve is projected into the trimming view, and a matching tangent is looked for along this curve. The distance between these two matching tangents is the trim relief offset distance. This is illustrated in the picture below.</p>
      <p align="center"><img align="bottom" src="graphics/dfm_trim_relief_offset.gif"></p>
      <p class="para_division">If no matching tangents are found, and the trim relief starts at the correct angle (see starting angle check above) then the trim relief is considered as a pass, and the radii check is not performed.</p>
      <p class="para_division">If the distance from the solution point for the matching tangent, to the end of the break line is greater than Away Distance value(?) then the offset distance is considered an automatic pass, and the checking of the radii is skipped.</p>
      <div class="title_division">Checking Radii (computed third if required)</div>
      <p class="para_division">For the cases when the trim relief offset distance is less than Away Distance value(?) radii are checked from the flange breakline end point, to the first flat portion of the trimming curve after the trim relief offset point. If a radii is not within the site specified values below, then a non-conformance is reported.</p>
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               <p class="para_th">Trim Radii</p>
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            <th bgcolor="#c0c0c0" colspan="1" rowspan="1" valign="middle">
               <p class="para_th">Trim Relief Type</p>
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               <p class="para_th">Standard</p>
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">&gt; Minimum Standard Radii</p>
            </td>
            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">Cut Back Trim Line</p>
            </td>
         </tr>
         <tr valign="top">
            <th bgcolor="#c0c0c0" colspan="1" rowspan="1" valign="middle">
               <p class="para_th">1st Deviation</p>
               <p class="para_th">(adds die cost)</p>
            </th>
            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">&lt; Minimum Standard Radii to</p>
               <p class="para_td">Deviation Radii</p>
            </td>
            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">Add local trim notch</p>
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            <th bgcolor="#c0c0c0" colspan="1" rowspan="1" valign="middle">
               <p class="para_th">2nd Deviation</p>
               <p class="para_th">(higher cost)</p>
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">&lt; Deviation Radii</p>
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">N/A</p>
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      </table><br><p class="para_division">The picture below show radii that are evaluated up to the first flat that are not greater than the site values for a pass condition.</p>
      <p align="center"><img align="bottom" src="graphics/dfm_trim_relief_bad_radii.gif"></p>
      <div class="title_division">Cost Penalty</div>
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               <p class="para_th">Deviation</p>
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            <th bgcolor="#c0c0c0" colspan="1" rowspan="1" valign="middle">
               <p class="para_th">Complexity Result</p>
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               <p class="para_th">Added Cost</p>
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               <p class="para_th">Complexity Value</p>
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               <p class="para_td">Localized Trim Relief</p>
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               <ul>
                  <li>
                     <p class="para_item">...</p>
                  </li>
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">$XXX</p>
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">X</p>
            </td>
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">Relief Depth Less than Minimum Offset Distance value(?)</p>
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <ul>
                  <li>
                     <p class="para_item">...</p>
                  </li>
               </ul>
            </td>
            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">$XXX</p>
            </td>
            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">X</p>
            </td>
         </tr>
         <tr valign="top">
            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">Radius less than Minimum Standard Radii value(?) and greater than Deviation Radii value(?)</p>
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <ul>
                  <li>
                     <p class="para_item">...</p>
                  </li>
                  <li>
                     <p class="para_item">...</p>
                  </li>
               </ul>
               <p class="para_td"></p>
            </td>
            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">$XXX</p>
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">X</p>
            </td>
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">Radius less than Deviation Radii</p>
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <ul>
                  <li>
                     <p class="para_item">...</p>
                  </li>
                  <li>
                     <p class="para_item">...</p>
                  </li>
               </ul>
            </td>
            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">$XXX</p>
            </td>
            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="middle">
               <p class="para_td">X</p>
            </td>
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