<!DOCTYPE html
  PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<!--
Copyright (c) 2006 UGS Corp.

All Rights Reserved.

This software and related documentation are proprietary to UGS Corp.
-->
<html>
   <head>
      <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
      <title>Corner and Feed Rate Control</title>
      <script language="javaScript">
        abridged="false";
        displayConditions=new Array();
      </script>
      <link type="text/css" href="../css/main_styles.css" rel="stylesheet">
   </head>
   <body class="bodydocs" onload="top.pageLoader()" bgcolor="#FFFFFF">
      <div class="title_topic2" id="xps10_pagetitle">Corner and Feed Rate Control</div>
      <hr noshade="true">
      <p class="para_topic">Corner and Feed Rate Control is a dialog box common to Planar and Cavity Mill, Fixed and Variable Contour, and Sequential Mill. Similar dialogs and functionality also appear in Drive Curve Lathe and WireEDM. These options prevent the cutter from gouging the part as it cuts concave or convex corners. The tool path around a corner depends on how you set your corner control. You may dictate whether a sharp turn occurs or whether an arc is inserted in the tool path.</p>
      <p class="para_topic">You can control how the tool moves at corners as follows:</p>
      <ul>
         <li>
            <p class="para_item">For concave corners, it is possible for the cutter to make a smooth transition between interior part walls by automatically generating corner geometry (fillets) that are slightly larger than the cutter radius.</p>
         </li>
         <li>
            <p class="para_item">For convex corners, the tool can transition part walls by extending the adjacent segments or by rolling around the corner.</p>
         </li>
      </ul>
      <p class="para_topic">If you indicate that you want adjacent segments of a tool path to meet at a sharp turn and the segments cannot intersect, an arc will be added.</p>
      <table border="0">
         <tr>
            <td valign="top" align="left"><img align="left" src="../graphics/note.gif" alt="Note" title="Note"></td>
            <td valign="bottom" align="left" width="100%">
               <div class="para_note">
                  <p class="para_note_body"> Editing the individual boundary members may affect the corner and feed rate control. Refer to Custom Boundary Data.</p>
               </div>
            </td>
         </tr>
      </table>
      <p class="para_topic">Using slowdown feed rates in one or more steps as the tool encounters a wall also assures a smooth cutter transition between walls. As the cutter leaves the corner, it accelerates back to the Cut Feed Rate.</p>
      <p class="para_topic">The primary Corner Control options, Fillets and Slowdowns, are usually applied together. Both values are applied to all corners along the boundary wall that are within the specified range of Minimum Angle and Maximum Angle.</p>
      <p class="para_topic">You can also control the tool feed rate for circular arcs so that the &quot;chip load&quot; in circular portions of the tool path matches the chip load in the linear portions of the tool path. (This is because the feed rate is calculated at the center of the cutter. Therefore the feed rate at the side of the cutter that is cutting metal can actually be significantly higher or lower than the calculated feed rate.)</p>
      <p class="para_topic">Fillets can be applied when two successive moves (i.e., three output points) form an inside corner and neither move is along the tool axis.</p>
      <p class="para_topic">All segments of a spline or conic cut are processed as small line segments.</p>
      <table border="0">
         <tr>
            <td valign="top" align="left"><img align="left" src="../graphics/warning.gif" alt="Warning" title="Warning"></td>
            <td valign="bottom" align="left" width="100%">
               <div class="para_warning">
                  <p class="para_warning_body"> CAUTION: Under some circumstances fillets will not be generated. For instance, if a specified Fillet Radius is larger than the corner radius of the part, a fillet is not output. Other constraints may be inherent in the nature of the process. For Planar and Cavity Milling these constraints are: for Profile or Standard Drive, filleting occurs on all passes; and for any Zig process, filleting never occurs, except on the finish (profile) pass, if one has been selected. Note that the finish pass option is available in Planar Milling only.</p>
               </div>
            </td>
         </tr>
      </table>
      <p class="para_topic">However Slowdown Feed Rates are applied to corners, the slowdown occurs on the segments as the tool approaches the corner.</p>
      <table border="1" cellspacing="0" align="center">
         <tr>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Convex Corner</p>
            </td>
            <td colspan="1" rowspan="1" valign="middle">
               <p class="para_td">Adds arcs or extends tangents at convex corners</p>
            </td>
         </tr>
         <tr>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Circular Feed Rate Comp.</p>
            </td>
            <td colspan="1" rowspan="1" valign="middle">
               <p class="para_td">Adjusts all circle records to maintain the feed rate at the edge of the cutter rather than at the center</p>
            </td>
         </tr>
         <tr>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Fillets</p>
            </td>
            <td colspan="1" rowspan="1" valign="middle">
               <p class="para_td">Adds arcs to cutting passes at corners that fall within the range of the specified Minimum and Maximum</p>
            </td>
         </tr>
         <tr>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Slowdowns</p>
            </td>
            <td colspan="1" rowspan="1" valign="middle">
               <p class="para_td">Sets the length, starting location, and the rate of the slowdown</p>
            </td>
         </tr>
         <tr>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Corner Angle</p>
            </td>
            <td colspan="1" rowspan="1" valign="middle">
               <p class="para_td">Defines the smallest and largest angle to include when using Fillets and Slow downs</p>
            </td>
         </tr>
      </table><br><table border="0">
         <tr>
            <td valign="top" align="left"><img align="left" src="../graphics/note.gif" alt="Note" title="Note"></td>
            <td valign="bottom" align="left" width="100%">
               <div class="para_note">
                  <p class="para_note_body"> These options apply only in the following situations encountered in Planar Milling, Cavity Milling, Fixed and Variable Contouring, and Sequential Milling:</p>
               </div>
            </td>
         </tr>
      </table>
      <ul>
         <li>
            <p class="para_item">During cut and first cut moves</p>
         </li>
         <li>
            <p class="para_item">While cutting along part walls</p>
         </li>
      </ul>
      <table border="0">
         <tr>
            <td valign="top" align="left"><img align="left" src="../graphics/note.gif" alt="Note" title="Note"></td>
            <td valign="bottom" align="left" width="100%">
               <div class="para_note">
                  <p class="para_note_body">For example, fillets may be inserted in Follow Periphery operations along a wall, Profile operations, and the final Profile pass after Zig operations (in Planar Milling). The system will never insert fillets into Zig operations.</p>
               </div>
            </td>
         </tr>
      </table><a class="endOfDocLinks" href="com_convexcorner.html">Convex Corner</a><br><a class="endOfDocLinks" href="com_circuilar_feed.html">Circular Feed Rate Compensation</a><br><a class="endOfDocLinks" href="com_slowdowns.html">Slowdowns</a><br></body>
</html>