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      <title>Boundary Drive Method</title>
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      <div class="title_topic5" id="xps10_pagetitle">Boundary Drive Method</div>
      <hr noshade="true">
      <p class="para_topic">The Boundary Drive Method enables you to define cut regions by specifying Boundaries and Loops. Boundaries are not dependent on the shape and size of the Part Surfaces while Loops must correspond to exterior Part Surface edges. Cut regions are defined by Boundaries, Loops, or a combination of both. The Tool Path is created by projecting Drive Points from the defined cut region to the Part Surfaces in the direction of a specified Projection Vector. The Boundary Drive Method is useful in machining Part Surfaces requiring minimal Tool Axis and Projection Vector control.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/bndrydrvmeth.gif"></p>
      </div>
      <div class="title_figure">Boundary Drive Method</div>
      <p class="para_topic">The Boundary Drive Method works in much the same way as Planar Milling. Unlike Planar Milling, however, the Boundary Drive Method is intended to create finishing operations that allow the tool to follow complex surface contours.</p>
      <p class="para_topic">Like the Surface Area Drive Method, the Boundary Drive Method creates an array of Drive Points contained within an area. Defining Drive Points within a boundary is generally faster and easier than selecting Drive Surfaces. You cannot, however, control the tool axis or the projection vector relative to a drive surface when using the Boundary Drive Method. Planar boundaries, for example, cannot wrap around complex part surfaces to evenly distribute Drive Points or control the tool axis as illustrated in the following figure.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/drvptproj_ptsurf.gif"></p>
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      <div class="title_figure">Drive Points Projecting to Part Surface</div>
      <p class="para_topic">Boundaries may be created from a sequence of curves, an existing permanent boundary, points, or a face. They can define the exterior of the cut region as well as islands and pockets. Each boundary member is assigned an On, Tanto, or Contact tool position attribute. For a detailed discussion of how to create boundaries, refer to Permanent Boundaries.</p>
      <p class="para_topic">A boundary may exceed the size of the Part Surfaces, restrict a smaller area within the Part Surfaces, or coincide with the edges of the Part Surfaces as illustrated below. When the boundary exceeds the size of the Part Surfaces by a distance greater than the tool diameter, Edge Tracing may occur. This is generally an undesirable condition where the tool rolls over the edge of the Part Surface.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/bndrs.gif"></p>
      </div>
      <div class="title_figure">Boundaries</div>
      <p class="para_topic">When a boundary restricts an area within the Part Surface, the tool must position to the boundary using On, Tanto, or Contact. When the Cut Region coincides with the exterior edge, it is best to use Part Containment Loops (as opposed to boundaries) specified as On, Tanto, or Contact. These three options particularly affect how the tool positions on very steep Part Surfaces.</p>
      <p class="para_topic">The following options display in the Boundary Drive Method dialog box.</p>
      <table border="1" cellspacing="0" align="center">
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Drive Geomety</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Defines and edits a boundary defining Drive Geometry</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Boundary Intol, Boundary Outol</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Specify the inside and outside tolerance values for the boundary</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Boundary Stock</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Controls how much material is left along the boundary by specifying an offset val ue</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Part Containment</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Defines cut regions by creating loops along exterior edges of selected part sur faces and surface regions</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Pattern</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Defines the shape of the tool path</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Cut Type</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Defines how the cutter moves from one cut pass to the next</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Pattern Center</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Defines the center point of Concentric Arcs and Radial Lines cut patterns</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Cut Angle</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Determines the angle of rotation for the Parallel Lines Cut Patterns</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Display Cut Direction</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Displays cut direction vector for visual reference</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Inward/Outward</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Specifies a pocketing method that deter mines whether to cut from the inside out or the outside in of a Follow Pocket, Concentric Arcs, or Radial Lines cut type</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Stepover</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Specifies the distances between succes sive cut passes</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Additional Passes</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Specifies an additional number of passes that allow the tool to step toward the boundary in successive concentric cuts for Profile and Standard cutting patterns</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">More Drive Parameters</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Additional Parameters while generating the tool path</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Cut Regions</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Defines Start Points and specifies how cut regions are graphically displayed for visual reference</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Climb Cut /Conventional Cut</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Defines the direction the Drive Path cuts in relationship to the spindle rotation</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Projection Vector</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Determines how the Drive Points project to the Part Surface</p>
            </td>
         </tr>
         <tr>
            <th colspan="1" rowspan="1" valign="top">
               <p class="para_th">Display Drive Path</p>
            </th>
            <td colspan="1" rowspan="1" valign="top">
               <p class="para_td">Displays the Drive Path used to generate the Tool Path</p>
            </td>
         </tr>
      </table><br><div class="title_division">Drive Geometry</div>
      <p class="para_division">Edit displays the Edit Boundary Geometry dialog allowing you to add or subtract boundary members and the parameters associated with each.</p>
      <p class="para_division">Select displays the Boundary Geometry dialog allowing you to initially define boundaries. Once defined, they can be modified using Edit described above. Each boundary member may be assigned an On, Tanto, or Contact tool position. The Contact tool position is available only in Fixed and Variable Axis Surface Contouring and can be used only in the Boundary Drive Method with a fixed tool axis and only when specifying boundaries with Curves/Edges or Points.</p>
      <p class="para_division">The boundary members graphically represent the associated tool positions as illustrated below.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/tanto_on_cntct.gif"></p>
      </div>
      <div class="title_figure">Tanto, On and Contact</div>
      <div class="title_division">Contact Method</div>
      <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">Area Milling drive method using Cut Area geometry is the suggested approach for limiting the machining to selected faces for fixed axis contouring operations, and should be used instead of the Boundary Drive with contact method whenever possible.</p>
               </div>
            </td>
         </tr>
      </table>
      <p class="para_division">Unlike On or Tanto, the Contact point position changes in relation to the tip of the tool as it moves along a contoured surface. The tool drives along the surface until it comes in contact with the boundary. On contoured surfaces, the contact point position varies at the tip of the tool. Notice in the following figure that the contact point is on opposite sides of the tool tip when the tool is on opposite sides of the part.</p>
      <div class="figure">
         <p align="center"><img align="bottom" src="graphics/cntctptpos.gif"></p>
      </div>
      <div class="title_figure">Contact Point Positions</div>
      <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"> NOTE: Contact may not be used in combination with On or Tanto when specifying the tool position for a boundary. If you wish to use Contact for any one member, the entire boundary must use Contact.</p>
               </div>
            </td>
         </tr>
      </table>
      <p class="para_division">Contact is only available when using a fixed tool axis (a fixed tool axis can be achieved in Variable Contour by specifying Relative To Vector with Lead and Tilt values equal to zero) and a Projection Vector that is the same as the fixed tool axis. If these conditions are not met when using a Contact boundary, the following error message displays when you select Generate or Display Drive Path: </p>
      <p align="center"><img align="bottom" src="graphics/op_param_er.gif"></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: Contact Boundaries should always be Closed. Open Contact boundaries may produce unpredictable results.</p>
               </div>
            </td>
         </tr>
      </table>
      <p class="para_division">For information on using the Boundary Geometry dialog, refer to the discussion of Temporary Boundaries. Reselect enables you to redefine the entire set of boundaries.</p>
      <p class="para_division">Display highlights the currently active boundary for visual reference.</p>
      <div class="title_division">Boundary Intol, Boundary Outol</div>
      <p class="para_division">Boundary Intol and Boundary Outol allow you to specify the inside and outside tolerance values for the boundary.</p>
      <div class="title_division">Boundary Stock</div>
      <p class="para_division">Boundary Stock allows you control how much material is left along the boundary by specifying an offset value.</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"> NOTE: Boundary Stock is not applied when Tool Position is ON.</p>
               </div>
            </td>
         </tr>
      </table>
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