Defining a user coordinate system

To define a UCS, you can use any of the following methods:

    Specify a new origin and points on the positive x- and y-axes.

    Specify a new origin and point on the positive z-axis.

    Align the UCS with an existing entity.    

    Rotate the current UCS around any of its axes.    

    Align the UCS with its z-axis parallel to the current viewing direction.

    Align the UCS xy plane perpendicular to the current view.

When you define a new UCS, the UCS icon changes to indicate the origin and orientation of the new UCS.

To define a UCS by specifying a new origin and points on the positive x- and y-axes    

   1   Do one of the following to choose User Coordinate Systems ():

    On the ribbon, choose Draw > User Coordinate Systems or choose
View > User Coordinate Systems.

    On the menu, choose Tools > User Coordinate Systems > Select a Predefined UCS.

    On the UCS toolbar, click the Select a Predefined UCS tool.

    Type setucs and then press Enter.

   2   In the User Coordinate Systems dialog box, click Explore UCSs.

   3   In the Explorer, be sure that Coordinate Systems is selected, and click the New Item tool ().    

   4   In the prompt box, choose 3 Point.

   5   Select the new origin.

   6   Select a point on the positive x-axis.

   7   Select a point in the positive y direction.

   8   In the Explorer - Coordinate Systems element, type the name for the new UCS, and then close the dialog box.