Create Linear Dimensions

The elements of a simple linear dimension are shown in the diagram.

The diagram illustrates the following features:

• On the drawing, a pair of Dimension Points relates to a pair of points in the Design model.

• From each of these dimension points, a Projection Line is drawn on the drawing, Offset in a user-defined direction.

• Between the parallel projection lines, Dimension Lines are drawn. These have Terminators (normally arrows).

• Each dimension and projection line may have text associated with it.

The various elements (Projection line, Dimension line, and so on) of the dimensions are shown in the Members form as DPPT1, DPPT2 etc, owned by the dimension, for example, LDIM.

Note: The values shown in the dimension text are taken directly from the 3D Design model. If the points associated with the dimension points are moved in Design, the dimension can be updated automatically by selecting Graphics > Update > Annotation.

1. Create a Linear Dimension between the nozzles along the centre of an equipment by selecting the appropriate Dimensions layer in the Draft Explorer and selecting Create > Dimension > Dimension Linear from the main menu.

   The Create Linear Dimension form is displayed.

   

   This form allow you to apply settings for the Dimension and Projection Lines.

   View	Shows the name of the selected view.
   Direction	Shows the direction of the selected view.
   Type	Select from the dropdown list of options: Chain (chained), Tail (parallel) or Truncate (truncated parallel).
   Dimension Line
   Direction	Select line direction from dropdown list of options.
   Derived Direction	Select a derived direction using the Derived button.
   Terminators	Default set. Select from dropdown list to enter a different terminator.
   First Terminator	Default set. Select from dropdown list to enter a different first terminator.
   Projection Line
   Text	Select from a dropdown list of options.
   Angle	Default set. Enter a different value, if required.

   Note: All dimensions in Draft are defined with respect to 3D World directions.

2. Once the Create Linear Dimension form has been populated, select OK to display the Linear/Angular Dimensions form.

   

   This form is used to create the points that define the Dimensions and form the link with the 3D Model element.

   The list on the left of the form sets how Dimension Points are created. Item is selected in the list. This will create the dimension point at the origin (P0) of the design primitive.

   Create	Creates a point. The default is that the Create function must be used for each point.
   	Allows several points of the same type to be created one after the other. Selecting the symbol ticks the adjacent checkbox.
   Delete	Allows a Dimension Point to be deleted.
   Re-Attach	Allows a label to be re-attached.
   Gaps	Displays the Gap Manager form.
   Ppoint	Enter a P-point.
   Auto-show Linear Dimensions	Select to automatically show linear dimensions.

   Note: The symbol must be off if Dimension Points are to be created in different ways, or if the 3D Pos, Cursor or Matchline positioning options are to be used.

3. Select Create to allow for the nozzles to be picked in sequence in either the 2D View or in the 3D View.

   The name of the item, P-point or P-line under the cursor will be highlighted in a tool tip as the cursor moves around, and clicking it will select it.

   

4. Press Esc to finish the process.

   The distances between the nozzles are then dimensioned as shown in the illustration.