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      <title>Stepover</title>
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      <div class="title_topic2" id="xps10_pagetitle">Stepover</div>
      <hr noshade="true">
      <p class="para_topic"><b class="uiTerm">Stepover</b> is the distance between cut passes. Specify the distance directly by entering a constant value or percentage of the tool diameter, or indirectly by entering a scallop height and allowing the system to calculate the distance between cut passes.
      </p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/pcmill_frefi04.gif"></p>
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      <div class="title_figure">Stepover</div>
      <p class="para_topic"><b class="uiTerm">Stepover</b> options are:
      </p>
      <ul>
         <li>
            <p class="para_item"><b class="uiTerm">Constant</b></p>
         </li>
         <li>
            <p class="para_item"><b class="uiTerm">Scallop</b></p>
         </li>
         <li>
            <p class="para_item"><b class="uiTerm">Tool Diameter</b></p>
         </li>
         <li>
            <p class="para_item"><b class="uiTerm">Variable</b></p>
            <p class="para_item">Depending on the operation, in the <b class="uiTerm">Variable Stepovers</b> dialog box, either specify:
            </p>
            <ul>
               <li>
                  <p class="para_item">An allowable range.</p>
               </li>
               <li>
                  <p class="para_item">The number of passes for each stepover size. </p>
               </li>
            </ul>
         </li>
      </ul>
      <div class="title_division">Constant</div>
      <p class="para_division">Constant allows you to specify a fixed distance between successive cut passes. If the specified distance between passes does not divide into the area evenly, the system reduces the distance between passes to maintain a constant stepover.</p><a name="pcmill_com_millop_stepover_constant_stepover"></a><div class="figure">
         <p align="center"><img align="bottom" src="graphics/pcmill_frefi03.gif"></p>
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      <div class="title_figure">System Maintains a Constant Stepover</div>
      <p class="para_division">In the above figure, the user-specified stepover distance of .750 is reduced to .583 to maintain a constant stepover across the 3.50 width of the cut region.</p>
      <p class="para_division">For Profile and Standard Drive Patterns, Constant allows you to specify the distance between successive cut passes as well as the number of offsets by specifying an Additional Passes value. Additional Passes defines the number of passes in addition to the Profile or Standard Drive pass along the boundary.</p><a name="pcmill_com_millop_stepover_two_passes"></a><div class="figure">
         <p align="center"><img align="bottom" src="graphics/pcmill_frefi02.gif"></p>
      </div>
      <div class="title_figure">Two Additional Passes</div>
      <div class="title_division">Scallop</div>
      <p class="para_division">Scallop establishes a fixed distance between successive cut passes by allowing you to specifying the scallop height (height of material left between passes). The system calculates the stepover distance required to leave no more than the specified scallop height between passes. The calculated stepover may vary from cut to cut depending upon the shape of the boundary. To protect the tool from too heavy a load when removing material, the maximum stepover distance is restricted to two thirds of the tool diameter.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/pcmill_newfi06.gif"></p>
      </div>
      <div class="title_figure">Scallop Height</div>
      <p class="para_division">For Profile and Standard Drive Patterns, Scallop allows you to specify the scallop height as well as the number of offsets by specifying an Additional Passes value. Additional Passes represents the number of passes in addition to the one pass along the boundary (see the Two Additionl Passes figure).</p>
      <div class="title_division">Tool Diameter</div>
      <p class="para_division">Tool Diameter allows you to establish a fixed distance between successive cut passes by specifying a percentage of the tool diameter. If the distance between passes does not divide into the area evenly, the system reduces the distance between passes to maintain a constant stepover (see the  <a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/com_millop_stepover.html#pcmill_com_millop_stepover_constant_stepover');return(false);">System Maintains a Constant Stepover</a> figure).
      </p>
      <p class="para_division">For Ball End Mills, the system uses the full tool diameter as the Effective Tool Diameter. For all other cutters, the Effective Tool Diameter is computed as D - 2CR.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/pcmill_freat12.gif"></p>
      </div>
      <div class="title_figure">Effective Tool Diameter</div>
      <p class="para_division">For Profile and Standard Drive Patterns, Tool Diameter allows you to specify the distance between successive cut passes as well as the number of offsets by specifying an Additional Passes value. Additional Passes defines the number of passes in addition to the one Profile or Standard Drive pass along the boundary (see the  <a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/com_millop_stepover.html#pcmill_com_millop_stepover_two_passes');return(false);">Two Additional Passes</a> figure).
      </p>
      <div class="title_division">Variable</div>
      <p class="para_division">Variable creates stepovers for Zig-Zag, Zig, and Zig With Contour that adjust to assure the tool always cuts tangent to boundaries parallel to Zig and Zag cuts. For Follow Periphery, Follow Part, Profile, and Standard Drive patterns, Variable allows you to specify multiple stepover sizes and a corresponding number of passes for each size.</p>
      <p class="para_division">Depending on the cut type, one of the following two dialog boxes will display.</p>
      <p align="center"><img align="bottom" src="graphics/pcmill_frefi09.gif"></p>
      <p class="para_division">For Zig-Zag, Zig, and Zig With Contour, Variable enables you to establish an allowable range that the system uses to determine both the stepover size and the number of passes. The system calculates the minimum number of stepovers that will fit evenly between the walls parallel to the Zig and Zag passes and adjusts the stepover to assure the tool always cuts along the walls without leaving excess material.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/pcmill_frefi08.gif"></p>
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      <div class="title_figure">Variable Stepover for Zig-Zag</div>
      <p class="para_division">In the above figure, the user-specified Maximum Stepover is .500 and the Minimum Stepover is .250. The system calculates eight passes with a stepover of .363. This calculated value allows the tool to cut tangent to all walls parallel to the Zig and Zag cuts.</p>
      <p class="para_division">Specifying the same value for Max and Min Stepover will produce a rigidly fixed stepover that may leave uncut material along the walls parallel to the Zig and Zag cuts as illustrated below.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/pcmill_frefi07.gif"></p>
      </div>
      <div class="title_figure">Same Max and Min Values</div>
      <p class="para_division">For Follow Periphery, Follow Part, Profile, and Standard Drive, Variable enables you to specify multiple stepover sizes and a corresponding number of passes for each size.</p>
      <p class="para_division">The first section of the dialog box always correspond to the passes nearest the boundary. The subsequent sections of the dialog box progress toward the center of the pocket as illustrated below.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/pcmill_frefi06.gif"></p>
      </div>
      <div class="title_figure">Follow Periphery, Variable Stepover</div>
      <p class="para_division">When the combined Step Sizes and Number of Passes exceed or fall short of the area to be machined, the system adds or subtracts passes from the center of the cut region. In the following figure, for example, the combined Step Sizes and Number of Passes exceed the size of the pocket. The system maintains the specified Number of Passes nearest the boundary (two passes), but reduces the number of passes in the center of the pocket from the specified ten to five.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/pcmill_frefi05.gif"></p>
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      <div class="title_figure">Follow Periphery, Variable Stepover</div>
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            <td valign="top" align="left"><img align="left" src="../graphics/note.gif" alt="Note" title="Note"></td>
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               <div class="para_note">
                  <p class="para_note_body"> NOTE: The Variable option essentially defines additional passes when used in combination with Profile or Standard Drive. The Additional Passes option therefore becomes inactive. Keying in a value for Additional Passes when using Profile or Standard Drive does not affect the processor.</p>
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