Ch 11: Dimensioning

AutoCAD 2012and

AutoCAD LT 2012 Essentials

By Scott Onstott

Ch 11: Dimensioning

Accessing Dimension Style Manager• Use the DIMSTYLE command• D is the command alias for DIMSTYLE• Button in expanded Annotation panel• Choose the current dimension style

in the adjacent drop down

Ch 11: Dimensioning

Dimension Style Lines Tab• Control characteristics of

dimension and extension lines• Always use real world values• It is the best practice to assign

properties ByBlock for dimensions• Use the preview image to make

sense of changes that you make on the tab; it is a dynamic preview

Ch 11: Dimensioning

Symbols and Arrows• Select arrowhead symbol• Enter arrowhead size in real world size• Unit (i.e. inch or centimeter) is set in

the UNITS command

Ch 11: Dimensioning

Dimension Sub-Styles• Create sub-styles by clicking the

New button in the Dimension Style Manager

• Open the “Use For” drop down in the Create New Dimension Style dialog box and select a dimension type

• The style preview shows the settings for the parent style plus all sub-styles

• Sub-styles allow you to maintain different settings for each type of dimension object

Ch 11: Dimensioning

Anatomy of a Linear Dimension• Linear dimensions have two extension lines

which point at the measured feature• Perpendicular to the extension lines is the

dimension line which is either broken by or has text that appears just above the line

• Dimension text automatically reports the actual distance between the extension lines

• You can override the dimension text but care should be taken to keep the dimensions “honest”

• Preference should be given to changing the geometry rather than overriding dimension text

Ch 11: Dimensioning

Linear Dimension Orientation• You choose whether linear dimensions will

be horizontal or vertical by locating the dimension line relative to the extension lines

• In cases where the first and second extension line origin points are neither horizontal nor vertical relative to each other, the location you choose for the dimension line determines whether the dimension object will measure a vertical or horizontal distance

Ch 11: Dimensioning

Aligned Dimensions• Aligned dimensions measure

1,2,3,4,and 5 in the graphic• Aligned dimensions are neither

horizontal nor vertical• Use aligned dimensions to measure

lines that are at an angle with respect to the cardinal directions

• Shortcut: press Enter when asked to select the first extension line origin and then select the angled line and both extension line origins will be selected at the ends of the line

Ch 11: Dimensioning

Other Dimension Types• Angular dimensions measure

angles between lines (53 and 37 degrees in the graphic)

• Use DIMCENTER to add a center mark within an arc or circle

• Multileaders lead the eye from a geometric feature to descriptive text

• Multileaders are associative objects that link the arrowhead, leader and text into an object that can be grip edited

Ch 11: Dimensioning

Baseline Dimensions • As the name suggests,

baseline dimensions all share one extension line, called the baseline

• Baseline dimensions all reference the same base point to eliminate cumulative errors that can crop up due to rounding errors between consecutive adjacent dimensions