<!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>Hole tips and techniques</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_topic3" id="xps10_pagetitle">Hole tips and techniques</div>
      <hr noshade="true">
      <table cellspacing="4" align="center">
         <tr valign="top">
            <td bgcolor="#f7f7f7" colspan="1" rowspan="1">
               <p class="para_td"> <a class="links" href="javascript:void(0)" onclick="top.openFile('sheetmetaldes/smfea_hole.html');return(false);">Hole Overview</a></p>
            </td>
            <td bgcolor="#f7f7f7" colspan="1" rowspan="1">
               <p class="para_td"> <a class="links" href="javascript:void(0)" onclick="top.openFile('sheetmetaldes/smfea_hole_dial.html');return(false);">Options</a></p>
            </td>
            <td bgcolor="#f7f7f7" colspan="1" rowspan="1">
               <p class="para_td"> <a class="links" href="javascript:void(0)" onclick="top.openFile('sheetmetaldes/build_multi_parts.html');return(false);">Related Topics</a></p>
            </td>
         </tr>
      </table><br><div class="title_division">Punch vs. through holes</div>
      <p class="para_division">If you want to create one hole that pierces the target solid just once, use the <b class="uiTerm">Punch Hole</b> type. The <b class="uiTerm">Through Hole</b> type creates multiple Holes piercing all faces in its path between the placement face and the through face. The diameter, position, and orientation of through holes are associative to the first (or master) hole that lies on the placement face.
      </p>
      <div class="title_division">Model state</div>
      <p class="para_division">Newly created features will track the state of the model, so that the RPO dimensions will only be applied during update when the model is in that state. When the model is updated in the creation state, the system will rebuild the model using the feature parameters. When the model is in any other state, the feature will update using existing curve mapping techniques for distortion, which do not use <b class="uiTerm">RPO Dimensions</b> or <b class="uiTerm">Edge Offsets</b>. The feature <b class="uiTerm">Creation State</b> is a function of the Sheet Metal features (for example, flanges) that affect it. The next section describes the<b class="uiTerm"> Model State</b> in more detail.
      </p>
      <p class="para_division">It is important to understand how RPO Dimensions relate to the feature <b class="uiTerm">Creation State</b>. The state of any Sheet Metal feature can be formed, unformed, or some intermediate state. The feature's creation state is a function of the states of the Sheet Metal features upon which the hole depends. A given hole is dependent on any Sheet Metal features above it in the feature tree. It also depends on any Sheet Metal features that affect any edges or faces referenced by that feature. RPO dimensioning will be ignored during model update if the state of any of these features is different than at the time of creation of the <b class="uiTerm">Hole</b> or <b class="uiTerm">Slot</b> feature.
      </p>
      <p class="para_division">For example, if you were to place a hole on an unformed flange and use RPO to position that hole, the RPO will be ignored when you form the flange. This is because the RPO is a two dimensional measurement. It cannot bend with the flange to measure the distance to the center of the hole across the bend of the formed flange.</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">While a hole is not in its <b class="uiTerm">Creation State</b>, the expressions that control the hole are locked and cannot be edited.
                  </p>
               </div>
            </td>
         </tr>
      </table>
      <div class="title_division">Edit parameters</div>
      <p class="para_division">If you edit the <b class="uiTerm">Hole</b> feature using the <b class="uiTerm">Edit Parameters</b> dialog box, the system will determine if the model is in the feature <b class="uiTerm">Creation State</b>. If you have the Sheet Metal <b class="uiTerm">Preference</b> set to <b class="uiTerm">Enforce Creation State Editing</b> you will not be able to change the feature in its <b class="uiTerm">Not&ndash;As&ndash;Created State</b>. If you do not have the preference set that you will be shown a message that allows you to <b class="uiTerm">Snap to Creation State</b>. If the feature has RPO dimensions, those dimensions will apply regardless of the original <b class="uiTerm">Creation State</b>. You should beware of this because the RPO dimensions may not apply as intended in the current state. You can disable editing when not in the Creation State by choosing the <b class="uiTerm">Enforce Creation State Editing</b> option in the <b class="uiTerm">Preferences</b> dialog box.
      </p>
      <p class="para_division">Optionally, you can select the <b class="uiTerm">Snap To Creation State</b> button on the <b class="uiTerm">Warning</b> dialog box to put the model back into the state it was in when the hole was created.
      </p>
      <p class="para_division">From the <b class="uiTerm">Edit Parameters</b> dialog box, you can remove all RPO dimensions by changing the positioning method from <b class="uiTerm">RPO</b> to <b class="uiTerm">Edge Offsets</b>, but you cannot edit or delete <b class="uiTerm">RPO Dimensions</b>. You can use the <b class="uiTerm">Edit Positioning Dimensions</b> function for that purpose.
      </p>
      <p class="para_division"><b class="uiTerm">Edit Parameters</b> will always rebuild the <b class="uiTerm">Hole</b> feature in the undistorted state.
      </p>
      <p class="para_division">You can only edit the parameters of the first (or master) through type hole. Even if you choose one of the other hole features, the parameters of the first (or master) hole will be changed. In turn, this will cause the other Holes to be updated to match the changes made to the first (or master) hole.</p>
      <div class="title_division">Edit positioning dimensions</div>
      <p class="para_division">On the <b class="uiTerm">Edit Feature</b> dialog box, it is possible to select Holes within the <b class="uiTerm">Edit Positioning Dimension</b> function if the hole was positioned using <b class="uiTerm">RPO</b>. Upon selecting the hole, the system will determine if the model is in the creation state of the feature. If the model is not in the hole's creation state, a message will display, and the function will exit.
      </p>
      <p class="para_division">If the feature creation state matches the current <b class="uiTerm">Model State</b>, then the normal <b class="uiTerm">Reposition Feature</b> dialog box will be displayed. RPO dimensions may be added, modified, or deleted.
      </p>
      <p class="para_division">Since the model must be in the feature's creation state, the feature will always be rebuilt in the undistorted state.</p>
      <p class="para_division">Legacy hole features cannot be edited using <b class="uiTerm">Edit Positioning Dimensions</b>.
      </p>
      <div class="title_division">Update</div>
      <p class="para_division">Whenever a hole updates, the system will determine if the hole creation state matches the current model state. If the states match, the system will rebuild the undistorted hole using <b class="uiTerm">Edge Offsets</b> or <b class="uiTerm">RPO Dimensions</b>, whichever applies. If the states don't match, the hole will update by performing curve mapping to the proper target faces in order to generate the distorted hole.
      </p>
      <p class="para_division">In addition, if you were to change the model so that a new face is created between exiting through type holes, a new through hole will not automatically be created on the new face. The faces on which the through holes are created are only identified at creation time.</p>
      <div class="title_division">Part conversion</div>
      <p class="para_division">Legacy hole features do not contain the feature creation state information that allows the system to determine when to build them as undistorted or distorted features. When this information is unavailable, the system will build the feature using the existing distortion technique. If you edit the feature, the current model state will become the creation state of the feature.</p>
      <p class="para_division">Pre&ndash;Unigraphics version 15 hole features do not contain RPO dimensions. Such features will not be available in the <b class="uiTerm">Edit Positioning Dimensions</b> function. You can add <b class="uiTerm">RPO Dimensions</b>, if desired, from the <b class="uiTerm">Edit Parameters</b> dialog box.
      </p>
      <div class="title_division">Feature conversion</div>
      <p class="para_division">It is now possible to convert other Modeling features (such as <b class="uiTerm">Simple Holes</b> or <b class="uiTerm">Simple Hole Instances</b>) into Sheet Metal holes. See <a class="links" href="javascript:void(0)" onclick="top.popUpPage('modeling/index.html?goto=modeling/title_page.html&vars=-aux,-home','linkInter','menubar=yes,status=yes,resizable=yes,toolbar=yes,scrollbars=yes,location=no,directories=no');return(false);">Modeling Help</a> for further explanations.
      </p>
      <p class="para_division">Converted holes are named SMD_SIMPLE_HOLE features and behave like hole features with RPO dimensions.</p>
      <div class="title_division">Converted holes and instances</div>
      <p class="para_division">It is possible to convert an instance of a Modeling <b class="uiTerm">Hole</b> into an instance of a Sheet Metal hole.
      </p>
      <p class="para_division">If you convert an instance of a hole, the whole instance set is converted.</p>
      <p class="para_division">All instances in an instance set form and unform together. </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">Their representations may differ depending on their underlying surface.</p>
               </div>
            </td>
         </tr>
      </table>
   </body>
</html>
