AutoCAD 2008 User's Guide > Create and Modify Objects > Use Precision Tools > Use Coordinates and Coordinate Systems (UCS) > Specify Workplanes in 3D (UCS) > Understand the User Coordinate System in 3D > 
Understand the User Coordinate System in 3D
Concept Procedure Quick Reference
 
 
 

To specify a new UCS with three points

  1. Click Tools menu New UCS 3 Point.At the Command prompt, enter ucs.

  2. Specify a new origin point. This is the point (0,0,0) on the new UCS.
  3. Specify a point on the positive X axis of the new UCS.
  4. Specify a point on the positive XY plane of the new UCS.