<!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>Cut Between Levels &mdash; Zlevel</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">Cut Between Levels &mdash; Zlevel</div>
      <hr noshade="true">
      <p class="para_topic">This option (Cutting Parameters dialog, Connections page) creates extra cuts when there is a gap between the cut levels in Zlevel machining. Cut Between Levels eliminates the large scallops in shallow regions left from standard level-to-level machining. You don't have to create a separate area milling operation for non-steep areas, or use a very small depth of cut to control scallops in non-steep areas. </p>
      <p class="para_topic">Cutting between the levels minimizes excessive tool wear or even breakage from rapidly loading and unloading the tool in areas that have large scallops left behind from previous operations. When used for semi-finishing, it produces a more uniform stock. When used for finishing, there are fewer retracts and engages, and the surface finish is more consistent. </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"><b class="uiTerm">Cut Between Levels</b> is only available for <b class="uiTerm">ZLEVEL_PROFILE</b> and <b class="uiTerm">ZLEVEL_PROFILE_STEEP</b>.
                  </p>
               </div>
            </td>
         </tr>
      </table>
      <p class="para_topic">The figures below shows how Cut Between Levels affects the tool path. The first figure has shallow regions with large gaps. The second figure shows the additional gap tool path (in red) generated with Cut Between Levels.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/zlev-cut_btwn_off_thck.gif"></p>
      </div>
      <div class="title_figure">Without Cut Between Levels</div>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/zlev-cut_btwn_on_thck.gif"></p>
      </div>
      <div class="title_figure">With Cut Between Levels</div>
      <div class="title_division">Options</div>
      <p class="para_division">Cut Between Levels options include:</p>
      <ul>
         <li>
            <p class="para_item">Stepover</p>
         </li>
      </ul>
      <p class="para_division">This is the stepover used when machining the gap areas. With the default Use Depth of Cut option, the stepover matches the depth of cut of the current cut range. To further control the scallop height in these areas, you can also specify the stepover distance. &nbsp;See  <a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/com_millop_stepover.html');return(false);">Stepover</a> for a description of the other Stepover options (Constant, Scallop, Tool Diameter).
      </p>
      <p class="para_division">Since each cut level range can have a different depth of cut, if you specify Use Depth of Cut, then the range it lies in will determine the stepover for that gap region. If a gap region spans several ranges that don't have cut levels defined, then the gap region uses the minimum depth of cut of the spanned ranges.</p>
      <ul>
         <li>
            <p class="para_item">Max Cut Traverse </p>
         </li>
      </ul>
      <p class="para_division">This defines the longest distance that you want the tool to feed along the part when not cutting. When the system needs to connect different cutting areas, if the distance is less than this, the tool will feed along the part. If the distance is larger than this, the system will use the current transfer method to retract, traverse, and engage to the next location. Specify this value as a distance or a percent of the tool diameter.</p>
      <div class="title_division">Cut Levels</div>
      <div class="title_division">Critical Depths</div>
      <p class="para_division">Topping off critical depths affects the gap regions for Zlevel. The figure below shows how a single gap region is broken into two regions (A) by the Top Off Critical Depths tool path. &nbsp;</p>
      <div class="figure"><a name="mfgmill_zlev-fig7"></a><p align="center"><img align="bottom" src="graphics/zlev-fig7.gif"></p>
      </div>
      <div class="title_figure">Top Off Critical Depths Tool Path</div>
      <p class="para_division">To top off critical depths:</p>
      <ol type="1" start="1">
         <li>
            <p class="para_item">From the operation dialog, select Cut Levels.</p>
         </li>
         <li>
            <p class="para_item">On the Cut Levels dialog, Select Single  <img align="bottom" src="graphics/range_single.gif" border="0">.
            </p>
         </li>
         <li>
            <p class="para_item">Select Top Off Critical Depths  <img align="bottom" src="graphics/tog_on.gif" border="0">.
            </p>
         </li>
      </ol>
      <div class="title_division">Tops and Bottoms of Ranges</div>
      <p class="para_division">Gap tool paths are restricted to Cut Area surfaces that are also inside the defined Cut Levels range. Surfaces aren't cut when:</p>
      <ul>
         <li>
            <p class="para_item">they weren't selected as a Cut Area surface</p>
         </li>
      </ul>
      <p class="para_division">or,</p>
      <ul>
         <li>
            <p class="para_item">they are outside of the Zlevel range</p>
         </li>
      </ul>
      <p class="para_division">When the top or bottom of a range is at a horizontal surface, and the surface is selected as a cut area, the tool path is generated based on the parameters set for Cut Between Levels. &nbsp;In the figure below, the orange faces are the cut area. The top of the pad (1) is at the top of the Cut Levels range, so it is cut. The floor of the pocket (2) is outside of the cut levels, so it is not cut. The flat face across the entire block is within the cut levels, but not part of the orange cut area, so it is not cut.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/zlev-cutarea_range.gif" usemap="#genid_mfgmilling377" border="0"></p><map name="genid_mfgmilling377">
            <area shape="circle" coords="260,20,100" alt="top of pad" title="top of pad">
            <area shape="circle" coords="325,100,100" alt="floor of pocket" title="floor of pocket"></map></div>
      <div class="title_figure">Gap Tool Path </div>
      <div class="title_division">Sequencing Gap and Zlevel Tool Paths</div>
      <p class="para_division">The Zlevel and gap tool paths are sequenced and ordered as follows:</p>
      <ul>
         <li>
            <p class="para_item">The Zlevel tool path is machined top-down and uses the same connection methods as it would without the Cut Between Levels option.</p>
            <ol type="1" start="1">
               <li>
                  <p class="para_item">After each zlevel cut is completed, the tool begins to cut the level below it.</p>
               </li>
               <li>
                  <p class="para_item">While cutting the lower level, the system looks for gaps between lower level and the previous level above it.</p>
               </li>
               <li>
                  <p class="para_item">When a gap is found, the system cuts the gap, and then continues cutting the lower level until if finds another gap, or completes the level.</p>
               </li>
               <li>
                  <p class="para_item">The system connects the gap cutting with the lower cut level based on the Max Cut Traverse distance.</p>
               </li>
            </ol>
         </li>
      </ul>
      <p class="para_division">If Max Cut Traverse is exceeded, a traverse to the next level takes places. If the move to the next level is within the Max Cut Traverse distance, the tool makes a direct on-part move (shortest distance) to the next level without traversing. </p>
      <ul>
         <li>
            <p class="para_item">Level-to-level connections that violate a gap region are replaced with a traversal move.</p>
         </li>
         <li>
            <p class="para_item">The start point of a new level is placed so that it isn't adjacent to a gap region. &nbsp;(This applies to a closed boundary.)  This prevents the connection to the next level going through the gap.</p>
         </li>
         <li>
            <p class="para_item">Gap machining engages and retracts from the gap paths along the tool axis. Engage/retracts to and from standard zlevel cuts use the style you specified.</p>
         </li>
         <li>
            <p class="para_item">The gap tool path is machined immediately after its lower trace.</p>
         </li>
         <li>
            <p class="para_item">Connections are made from the zlevel cut to the gap area. After the gap area is cut, the tool returns to the lower level.</p>
         </li>
         <li>
            <p class="para_item">The lower trace is split in order to minimize retracts and engages to and from the gap tool path.</p>
         </li>
      </ul>
      <div class="title_division">Effect of Max Cut Traverse</div>
      <p class="para_division">When the tool moves between gap regions, depending on the Max Cut Traverse distance, it either traverses along the part to the start point on the lower contour, or retracts and traverses to the next Zlevel or gap machining area. To eliminate motions where the tool is not cutting, set Max Cut Traverse to zero. Engages and retracts then occur directly along the tool axis. </p>
      <p class="para_division">The figures below show how the tool moves from the lower Zlevel tool path to the gap tool path area.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/zlev-max_cut_on_thck.gif"></p>
      </div>
      <div class="title_figure">Moving from Lower Zlevel to the Gap Tool Path</div>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/zlev-max_cut_excd_thck.gif"></p>
      </div>
      <div class="title_figure">Same Part with Max Cut Traverse Exceeded</div>
      <div class="title_division">Traversing Multiple Sub-Regions</div>
      <p class="para_division">The figure below illustrates how the software traversed between multiple sub-regions.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/zlev-mult_sub_thck.gif"></p>
      </div>
      <div class="title_figure">Traversing Between Multiple Sub-Regions</div>
      <div class="title_division">Sequencing Open Cut Areas</div>
      <p class="para_division">The pictures below help to illustrate the difference between level first cuts, and depth first cuts on a part with open regions.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/zlev-fig20.gif"></p>
      </div>
      <div class="title_figure">Level First Zlevel Tool Path with Cut Between Levels On</div>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/zlev-fig21.gif"></p>
      </div>
      <div class="title_figure">Depth First Zlevel Tool Path with Cut Between Levels On</div>
      <div class="title_division">Tool Holder</div>
      <p class="para_division">When Use Tool Holder (Cutting Parameters dialog, Containment page) is turned on, the containment boundaries are determined by the tool holder collisions.</p>
      <p class="para_division">See  <a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/com_millop_use_tl_hold.html');return(false);">Use Tool Holder</a> for more information on this option.
      </p>
   </body>
</html>