About Placing Datum Feature Symbol
You can create Datum Feature symbols and specify properties using the Datum Feature ribbon tab.
When you launch the Datum Feature Symbol command, the dynamic preview of the datum feature symbol is available. The previewed Datum Feature Symbol consists of the frame, triangle, and leader connecting to the frame.
You must select a surface reference to place the datum feature symbol to the surface at the selected point in the annotation plane that is currently active.
When the geometry projection is not horizontal or vertical, the horizontal elbow is automatically added to the preview, providing the connection between the leader and the frame.
Linear Dimensions Selection
When you select the extension line of a linear dimension, the datum feature triangle is attached to the extension line at the point where the dimension line touches the extension line. The datum feature symbol is placed in the same annotation plane where the dimension is located regardless of whether the current annotation plane is active.
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Moving the dimension automatically updates the position of the datum feature symbol preserving the point of attachment at the intersection of the dimension and extension lines.
When the Datum Feature Symbol is placed attached to the dimension extension line, further dimension movement causes automatic update of the Datum Feature Symbol position preserving the attachment to the intersection of the dimension line and extension line.
When the extension line is not horizontal or vertical, you can use the leader with no elbow to connect the datum feature symbol frame to the triangle
When the extension line is not horizontal or vertical in the currently active annotation plane, you can use the leader with elbow to connect the datum feature symbol frame to the triangle.
When datum feature symbol is attached to the extension line of the dimension whose arrows point outside the extension lines, the arrow type of the dimension adjacent to the selected extension line changes to be None to avoid the overlapping of the arrow and datum feature symbol.
Selecting the dimension line of a linear dimension, automatically places the triangle of the datum feature symbol in the middle of the dimension line between extension the lines. The datum feature symbol is placed in the same annotation plane where the dimension is located regardless of whether the current annotation plane is active.
Selecting a Radial Dimension
Selecting a radial dimension as the datum feature symbol reference, the symbol is attached to the middle of the elbow. The datum feature symbol is placed in the same annotation plane where the dimension is located regardless of whether the current annotation plane is active.
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When the datum feature symbol is attached to the middle of the elbow, modifying the dimension or GTOL automatically updates the position of the datum feature symbol position preserving the point of attachment at the middle of the elbow.
Selecting Diameter Dimension
When you select a diameter dimension as the datum feature symbol reference, the symbol attaches to the dimension according to the elbow state of the dimension. When an elbow is available, the datum feature symbol is attached to the middle of the elbow as shown below.
When the diameter dimension does not have an elbow, the datum feature symbol attaches to the diameter dimension line.
When the dimension text is displayed outside the dimension line, the datum feature symbol attaches to the end dimension line that is opposite to the dimension text.
When the dimension text is displayed within the dimension line, the datum feature symbol is attaches to the end of the random dimension line.
When datum feature symbol is attached to the diameter dimension line where arrows are located outside the reference geometry, the arrow type of the dimension arrow adjacent to the datum feature symbol changes to None to avoid the overlapping of the arrow and datum feature symbol.
When the datum feature symbol is placed attached to a diameter dimension, you can change the position of the datum feature symbol so that it is attached to the dimension elbow or to the dimension line.
Selecting a GTOL
When you select a GTOL as the datum feature symbol reference, the symbol is attaches to the closest point on the top or bottom boundary of the GTOL frame. The datum feature symbol is placed in the same annotation plane where the dimension is located regardless of the current annotation plane is active.
When the Datum Feature Symbol is placed attached to a GTOL, it is possible to change the position of the Datum Feature Symbol to be either attached to the GTOL frame or to the elbow attached to the GTOL.
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When the Datum Feature Symbol is attached to the GTOL frame, re-positioning of GTOL automatically updates the datum feature symbol position preserving the attachment point on the GTOL frame. You can move the datum feature symbol along the boundary of the GTOL frame .