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8/25/2014

DIMENSIONING IN CAD
DRAWINGS

DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

CHAPTER 9
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0
DIMENSION
ING IN CAD
DRAWINGS

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

1

8/25/2014

DIMENSIONING
To communicate a design, a drawing must convey more than
merely graphic entities and text
...

The necessar y dimensions often are more impor tant than the
drawing itself
...
Therefore, accurate dimensioning is a
necessity in drawing
...

DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

DIMENSIONING ST YLE
The command DDIM enables you to create dimension style
families and set the dimension variables
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DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

3

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DIMENSIONING ST YLE
Set Variables for Controlling Text and Feature Scaling
Steps:
Click Fit
The following variables can be made:
Fit options;
Text placement;
Scale for dimension feature; and
Fine tuning
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DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

4

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DIMENSIONING ST YLE

DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

DIMENSIONING ST YLE

DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

5

8/25/2014

DIMENSIONING ST YLE

DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

T YPES OF DIMENSIONING COMMANDS
There are various types of dimensioning available in AutoCAD
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Linear Dimension
Linear dimension refers to a group of dimensions that
measure between two points
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Linear dimensions can be horizontal, aligned or rotated
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To rotate the extension lines, enter “r” (Rotated
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DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

LINEAR DIMENSION
To create an aligned dimension
From the Dimension menu, choose Aligned;
Press ENTER to select the object to dimension or specify the first and
second extension line origin;
Edit the text content or angle; and
Specify the dimension line location
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DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

LINEAR DIMENSION
To create a Baseline linear dimension
From the Dimension menu, choose Baseline;
AutoCAD uses the origin of the base dimension first extension line (1)
and prompts for a second extension line of origin;
Use the End point object snap to select the end of the section (2) as
the second extension line of origin, or press ENTER to select any
dimension as the base dimension;
AutoCAD automatically places the second dimension above the first
at the distance specified by the Spacing option in the DDIM Geometry
dialogue box;
Use the Endpoint object snap to select the next extension line of
origin (3);
Continue to select extension line of origins; and
Press ENTER twice to end the command
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DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

LINEAR DIMENSION

DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

9

8/25/2014

LINEAR DIMENSION

DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

RADIAL DIMENSIONS
Radial dimensions measure the radii, diameters of arcs and
circles with optional centrelines or a centre mark
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To create a diameter dimension:
From the Dimension menu, choose Diameter;
Select the arc or circle to dimension;
Enter “t” to edit the dimension text content (optional);
Enter “a” to edit the dimension text angle (optional); and
Specify the dimension line location
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AutoCAD measures the radius and displays the text with the letter R in front of it
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For example, you can use them to measure the angle between
the radii of a circle
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You can also dimension an angle by specifying the angle
ver tex and endpoints
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DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

11

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ANGULAR DIMENSIONS
To create an angular dimension
From the dimension menu, choose Angular;
Select the circle at the first endpoint of the angle (1);
Specify the second endpoint of the angle (2);
Enter “t” or “m” to edit the dimension text content (optional);
Enter “a” to edit the dimension text angle (optional); and
Specify the dimension line arc location
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Leaders and their annotation are associative, which means if
you modify the annotation, the leader updates accordingly
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DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

LEADERS AND ANNOTATION
Creating a Leader Line
You can create a leader line from any point or feature in a drawing and
control its appearance as you draw it
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Leader colour is controlled by the current dimension line colour
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The type and size of arrowhead, if one is present, is controlled by the
first arrowhead defined in the current style
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Hook lines appear with multiline text and feature control frames if the
last leader line segment is at an angle greater than 15 degrees from
horizontal
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DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

13

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LEADERS AND ANNOTATION
Adding the Annotation
Leader annotation can be multiline text, a feature control frame or a
block reference
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Text annotation can be entered on the command line, a line at a
time, or in the Multiline Text Editor dialogue box
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Text or feature control frame annotation is placed at a specified
offset from the final endpoint of the leader
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DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

14

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EXERCISE
Give dimension to your drawing on
Exercise1F****
Exercise2F****
Exercise3F****
Exercise4F****
Exercise5F****
Exercise6F****
Exercise7F****
Exercise8F****

DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

EXERCISE9F****
Figure show side view and top view of an object
...
Use different layer for object and
dimension

DIPLOMA ENGINEERING IN AIRCRAFT MAINTENANCE
DWM 1203: TECHNICAL DRAWING AND CAD

FOR TRAINING PURPOSE ONLY
JPP/DWM1203/P09/REV00

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