To Align the UCS Dynamically With a 3D Solid

 
 
 
  1. Start a command supported by dynamic UCS.
  2. If necessary, click the Dynamic UCS button on the status bar () or press F6 to turn it on.
    NOTE:Dynamic UCS is not displayed by default on the status bar. Click Customize on the status bar and select Dynamic UCS to display it.
  3. Move your cursor over a planar face on a 3D solid.
  4. Complete the command.