Dimensioning using Tangents
Tangential dimensions are useful for dimensioning geometry where vertices are not available. This section shows how to create tangential dimensions on the following elements:
• Circle
• Arc
• Fillet
• Ellipse
• B-spline (closed, both interpolation and control)
 |
Tangential dimensions are not possible for open B-splines.
|
The following options are available to define the orientation of the tangential dimensions relative to geometry features:
|
Inclined
|
In an inclined plane.
|
|
Horizontal
|
In a horizontal plane.
|
|
Vertical
|
In a vertical plane.
|
|
Perpend to
|
Perpendicular to a reference line on your drawing.
|
|
Parall to
|
Parallel to a reference line on your drawing.
|
|
Parallel
|
Parallel to an imaginary line which passes through the selected extreme points on the geometry.
|
Creo Elements/Direct Drafting always chooses the extreme tangent points of a closed B-spline for dimensioning, for the B-spline with more than two tangent points at the given angle. If you select the points on a closed B-spline and a circle, arc, line, fillet or an ellipse, Creo Elements/Direct Drafting automatically chooses the tangent point of the B-spline which is closest to the selected point on that bspline.
The following figure shows examples of tangential dimensioning on a closed B-spline using each option.
Figure. Tangential Dimensioning
Inclined Dimensions
To create tangential dimensions along an inclined plane:
1. Press DIMENSION 1.
2. Pick TANGENTIAL and Inclined.
3. Select MANUAL or AUTO placement.
4. Type the inclination angle of the dimension in the User Input Line or move the cursor to define the angle.
5. Select the two elements to be dimensioned. The dimension appears at the cursor.
6. If MANUAL placement was selected, indicate the desired location for the dimension text(s), using the dimension trace for guidance.
7. Press END to end this command.
| | You can specify any value of the inclination angle, Creo Elements/Direct Drafting converts the angle between 360 and -360 degrees. |
Horizontal Dimensions
To create tangential dimensions in the horizontal plane:
1. Press DIMENSION 1.
2. Pick TANGENTIAL and Horizontal.
3. Select MANUAL or AUTO placement.
4. Select the two elements to be dimensioned. The dimension appears at the cursor.
5. If MANUAL placement was selected, indicate the desired location for the dimension text(s), using the dimension trace for guidance.
6. Press END to end this command.
Vertical Dimensions
To create tangential dimensions in the vertical plane:
1. Press DIMENSION 1.
2. Pick TANGENTIAL and Vertical.
3. Select MANUAL or AUTO placement.
4. Select the two elements to be dimensioned. The dimension appears at the cursor.
5. If MANUAL placement was selected, indicate the desired location for the dimension text(s), using the dimension trace for guidance.
6. Press END to end this command.
Perpendicular Dimensions
To create a tangential dimension perpendicular to a reference line:
1. Press DIMENSION 1.
2. Pick TANGENTIAL and Perpend to.
3. Select MANUAL or AUTO placement.
4. Identify a reference line. You can identify any line on the drawing as the reference line.
5. Select the two elements to be dimensioned. The dimension appears at the cursor.
6. If MANUAL placement was selected, indicate the desired location for the dimension text(s), using the dimension trace for guidance.
7. Press END to end this command.
Parallel to a Reference Line
To create a tangential dimension parallel to a reference line:
1. Press DIMENSION 1.
2. Pick TANGENTIAL and Parall to.
3. Select MANUAL or AUTO placement.
4. Identify a reference line. You can identify any line on the drawing as the reference line.
5. Select the two elements to be dimensioned. The dimension appears at the cursor.
6. If MANUAL placement was selected, indicate the desired location for the dimension text(s), using the dimension trace for guidance.
7. Press END to end this command.
Parallel Dimensions
To create a tangential dimension that is parallel to a line through the tangent points:
1. Press DIMENSION 1.
2. Pick TANGENTIAL and Parallel.
3. Select MANUAL or AUTO placement.
4. Select the two elements to be dimensioned. These define the orientation of the dimension. The dimension appears at the cursor.
5. If MANUAL placement was selected, indicate the desired location for the dimension text(s), using the dimension trace for guidance.
6. Press END to end this command.