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      <title>Thread Milling Sequence for Internal Threads</title>
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      <div class="title_topic3" id="xps10_pagetitle">Thread Milling Sequence for Internal Threads</div>
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      <p class="para_topic">A typical thread milling sequence for an internal right-hand thread is as follows:</p>
      <ol type="1" start="1">
         <li>
            <p class="para_item">The tool starts its motion from the From point and travels to the Start point in RAPID motion. From this point the tool then positions itself at the center of the hole to be milled at a distance above the top face by an amount specified as a RAPTO distance.</p>
         </li>
         <li>
            <p class="para_item">The tool moves down to the bottom of the hole at the APPROACH feed rate.</p>
         </li>
         <li>
            <p class="para_item">The tool moves by the engage distance towards the wall of the cylinder using APPROACH feed rate. If CUTCOM option is&nbsp;active, then CUTCOM will be output to the tool path.</p>
         </li>
         <li>
            <p class="para_item">The tool makes a helical ENGAGE move into the part until it is tangent to the major diameter and&nbsp;the helix angle is determined by the user specified pitch.</p>
         </li>
         <li>
            <p class="para_item">The tool cuts along the major diameter in a helical motion until it completes either one revolution and any optional OVERLAP distance or the predetermined length of thread, whichever comes first.</p>
         </li>
         <li>
            <p class="para_item">On completion of one revolution or the specified thread length, the tool makes a helical RETRACT move to the retract point using the retract feed rate.</p>
         </li>
         <li>
            <p class="para_item">If the machining of the thread is complete, the tool moves to the clearance point. The tool repositions itself on the clearance plane If number of geometries selected are more than one, or reposition the tool for another ENGAGE to make another revolution.&nbsp;</p>
         </li>
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         <p align="center"><img align="bottom" src="graphics/thrm_intrnl_htr_mill_seq.gif"></p>
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      <div class="title_figure">Internal Thread - Milling Sequence</div>
      <p class="para_topic">When you want to machine a blind hole, the tool initially positions itself at the bottom of the hole and follows the above sequence and stepover from bottom to top.</p>
      <p class="para_topic">The tool positions itself at a Rapto distance from the first engage point for external threads and follows the above mentioned steps.</p>
      <div class="title_division">Output</div>
      <ul>
         <li>
            <p class="para_item">The Avoidance points,&nbsp; FROM, START, RETURN and GOHOME points are output only if these points are defined.</p>
         </li>
         <li>
            <p class="para_item">The cutter compensation is active before every ENGAGE and is set to OFF after every RETRACT.</p>
         </li>
         <li>
            <p class="para_item">The toolpath for each geometry is computed exactly for the length of the thread. If the distance left for the last drive curve is less than the stepover and is also less than twice the tool pitch, then the drive curve is computed for more than one revolution ( 360 deg ). This computation is done for the length left for the last drive curve.</p>
         </li>
      </ul>
      <p class="para_division">The objective of this computation is to have continuous motion for the threads created.</p>
      <p class="para_division">If the distance remaining for the last drive curve is less than the stepover length and is greater than three times the tool pitch, then the stepover is set to twice the pitch and the final drive curve is computed for the remaining length. This drive curve traverse for more than one revolution.</p>
      <div class="title_division">Limitations</div>
      <ul>
         <li>
            <p class="para_item">To select a symbolic thread feature you must select the cylindrical face associated with the symbolic thread feature.</p>
         </li>
         <li>
            <p class="para_item">Each cylindrical face will have only one symbolic thread feature associated with it.</p>
         </li>
         <li>
            <p class="para_item">A single deselect cannot be performed on the geometry selected using the SELECT ALL&nbsp; button. You can deselect the geometry using the REMOVE / REMOVE ALL push button which is available in the EDIT mode.&nbsp;</p>
         </li>
      </ul>
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