To Preselect Datum Axis References
You can first select any of the following combinations of references in the graphics window, and then click > 
Axis to automatically define a fully constrained datum axis. Object-action selection allows you to define datum axes without using the Datum Axis dialog box.
Axis to automatically define a fully constrained datum axis. Object-action selection allows you to define datum axes without using the Datum Axis dialog box.The datum axis includes handles for specific sets of references, such as a datum point and planar surface, or a vertex and a datum plane. Hold down the SHIFT key to snap a handle.
References | Results |
|---|---|
One straight edge or axis | A datum axis is created through the selected edge. |
Two datum points or vertices | A datum axis is created constrained through each of the datum points or vertices. |
A datum point or vertex and a datum plane or planar surface | The datum axis is created through the datum point or vertex and perpendicular to the datum plane or planar surface. |
Two nonparallel datum planes or planar surfaces | If the planes intersect, a datum axis is created through the line of intersection. |
A curve or edge and one of its end points or a datum point | A datum axis is created constrained through the endpoint or the datum point and tangent to the curve or edge. |
A planar circular edge or curve, a datum curve, or the edge of a cylindrical surface | A datum axis is created through the center of the planar circular edge or curve and normal to the plane on which the selected curve or edge lies. For the edge of a cylindrical surface, the datum axis is created along the center-line of the cylindrical surface. |
A datum point and a surface | Location of datum point: • Datum point is on the selected surface A datum axis is created through the point and normal to the surface • Datum point is not on the selected surface The Datum Axis dialog box opens. |