Part Modeling > Datum Features > Coordinate Systems > About Coordinate Systems
About Coordinate Systems
Coordinate systems are reference features that can be added to parts and assemblies to do the following:
Calculate mass properties
Assemble components
Place constraints for Finite Element Analysis (FEA)
Provide manufacturing operation references for tool paths
Serve as a reference for positioning other features (coordinate systems, datum points, planes, imported geometry, and so on)
For most common modeling tasks you can use coordinate systems as direction references.
Click Model > Coordinate System to add a coordinate system to a model.
Coordinate systems can also be created using Sketcher. If you create a geometry coordinate system in a sketch feature, when you return to the modeling environment, the result is a datum coordinate system.
There are two kinds of coordinate systems: on-surface coordinate systems and offset coordinate systems.
The on-surface coordinate system defines a point by means of a primary placement reference and two offset references or by means of two to three primary references. The primary placement reference can be a quilt, a surface, or a datum plane. Planar, non-planar, cylindrical, conical, or spherical surfaces can be primary placement references. The offset values of a primary placement coordinate system can be defined in Linear, Radial, or Diameter measurements. If you select more than one primary reference, the Offset references collector is disabled and the offset handles do not appear in the preview.
The offset coordinate system defines a point by using a previously created coordinate system as a primary placement reference and three offset values that reference the primary placement reference. This application can be used to position sequential coordinate systems, for instance if you want to position a number of user-defined features (UDFs) on a model. The offset values of an offset coordinate system can be defined in Cartesian, Cylindrical, or Spherical measurements.