Lesson: Coordinate system

COORDINATE SYSTEMS
Absolute Coordinate System:
The Absolute Coordinate System is the coordinate system from which all objects are referenced.

This is a fixed coordinate system and hence the locations and orientations of every object in NX modeling space are related back to its origin. The Absolute Coordinate System (or “Absolute CSYS”) also provides a common frame of reference between part files. An absolute position at X=1, Y=1, and Z=1 in one part file is the same location in any other part file as well.


Work Coordinate System:
The Work Coordinate System (WCS) is what you will use for construction
when you want to determine orientations and angles of features. The axes of the WCS are denoted XC, YC, and ZC. (The “C” stands for “current”.)
It is possible to have multiple coordinate systems in a part file, but only one of them can be the work coordinate system.


Existing Coordinate Systems:
You can create an “existing coordinate system” (CSYS) whenever you need to
return to a specific location and orientation in modeling space.


Move the WCS:
Here, you will learn how to translate and rotate the WCS.


Translate the WCS:
This procedure will move the WCS origin to any point
you specify, but the orientation (direction of the axes)
of the WCS will remain the same.


 Choose FORMAT →WCS → ORIGIN


The Point Constructor dialog is displayed in the figure.

You either can specify a point from the drop down menu at the top of the dialog box or by entering the XY- Z coordinates in the XC, YC, and ZC fields.


NX for Engineering Design 3 0 Missouri University of Science and Technology


A majority of the work will be in relation to the working coordinate system rather than the absolute coordinate system. The default is the WCS.
The default action button is Inferred Point. The button is highlighted as shown in the figure. The name of the active icon appears above the top row of action buttons.

This is the point on the object, which is closest to the cursor. It can be the center of circle or end-point of a line and so on.


 Click CANCEL


Rotate the WCS:
You can also rotate the WCS around one of its axes.
 Choose FORMAT →WCS → ROTATE
The Rotate WCS dialog is shown on the right side.
The dialog shows six different ways to rotate the WCS around an axis. These rotation procedures follow the right-hand rule of rotation. You can also specify the angle to which the WCS be rotated.


 Click CANCEL

Save the Current Location and Orientation of the WCS
You can save the current location and orientation of the WCS to use as a permanent coordinate  system.


 Choose FORMAT →WCS → SAVE