Defining the AutoCAD Dimensioning Tool
It goes without saying that a project without dimensioning its components or at least its major parts and sections, is a design that couldn’t be executed or be real; In addition, the chances that it will remain sketches on paper are very high, unfortunately.
Therefore, it goes without saying that measurement tools are indispensable in the architectural career and engineering in general. This is true using the importance of the dimensions in identifying the last stage of a project which is the execution phase. Proceeding from this important notion, this is from where the Dimensions are a great feature in AutoCAD.
With AutoCAD, you can easily add dimensions to your drawings. All you have to do is pick two points to be dimensioned plus the location where you want the measurement line to be placed, and that’s it! You are done so far!
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| Learning the Dimension Feature in AutoCAD, Photo: My Pins Collection |
Understanding the Components of a Dimension
First of all, and before we start our tutorial, it is surely helpful for you to know and understand the names of the different parts of what we used to call a dimension in AutoCAD. Dimensions have several distinct elements, such as:
- Dimension text is the dimension value, usually shown inside or above the dimension line.
- Dimension line: This is the line that represents the distance being dimensioned. It indicates the direction and extent of a dimension. For angular dimensions, the dimension line is an arc.
- Arrowheads are symbols displayed at each end of the dimension line, in different sizes and shapes, for arrowheads or tick marks.
- Extension lines are the lines that extend from the object being dimensioned to the dimension line.
- Dimension line extension: This is a part of the dimension line that extends beyond the extension line.
- Extension beyond the dimension line: Specifies a distance to extend the dimension line past the extension line.
- Offset from origin: Sets the distance to offset the extension lines from the points on the drawing that define the dimension.
- Offset from dimension line: Sets the distance to offset the dimension value (text) from the dimension line.
You can control each of these components, by editing or creating dimension styles. The next figure (Fig.1) will graphically summarize all the previous content for you, with all the related labels, to facilitate the understanding.
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| Fig.1- The components of a dimension- Photo Source: www.autocadonline.eu |
Notice/ Disclaimer
- Depending on the AutoCAD version used, your UI (User Interface) might slightly differ from the one shown in this tutorial. Therefore it is highly advised to follow the global process as one whole knowledgeable entity (as it is) for educational purposes only.
- Actually, the AutoCAD © version used in this tutorial is the 2013 edition.
- The site is not responsible for any data loss or harm of any kind, resulting from a bad usage of the commands and tools listed in this post. Therefore the information contained in this article is provided as it is and is not to be modified under any condition.
Creating your First Dimension
So, let us create our first dimension as follows:
Likely to the Text Style used for creating text styles, the Dimension Style should be created with the aim that each style corresponds to a particular type or sort of dimensioning, and not for any other reason, anyway.
Why create many styles? For instance, we can create a specific style for dimensioning the General Gridline of a certain plan layout, then get down with other types of Styles to represent other sorts of dimensions and types, such as the walls’ partitioning, or the electrical layout, and so on...
How to Create a New Dimension Style in 4 Easy Steps?
Step #1- First open the Dimension Style Manager, and do the following: From the Home Tab go to the Annotation Panel and click on the small arrow below it which leads you to the Dimension Style button as shown in Fig.2 below.
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| Fig.2- The Dimension Style Command Location, Photo Source: 101architechprojectsandblogs.com |
Likely, you can get to the same tool by accessing the Annotate Tab, then the Dimensions Panel, and finally to the small arrow ↘ located on the bottom-right corner of the actual panel.
Step #2- Clicking the Dimension Style button will display the Dimension Style Manager dialog box, as shown below.
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| Fig.3- The Dimension Style Manager, Photo Source: www.101architechprojectsandblogs.com |
Step #3- Clicking on the New… button shown above will let you create a new dimension style to add to the existing ones already in the drawing, displayed on the left side list of Styles: in the same opened dialog box.
Step #4- Next, the Create New Dimension Style dialog box will appear, allowing you either to create a new dimension style from scratch or to start editing an existing dimension style within your currently opened drawing.
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| Fig.4- The Create New Dimension Style dialog box when prompted for a new dimension style, Photo Source: www.101architechprojectsandblogs.com |
A new given name will show up in the New Style Name box that you can change to your own. You have the option as well to start the process with a prototypical style based on an existing style already set on your drawing, which will save you a lot of time wasted on setting those endless routine configurations needed for every new style created.
The benefit of making as many of the Dimension Styles as we need resides within the capability of separating each sort of dimension type into individual styles that act differently within the same drawing;
For instance, we can lay out a drawing with two or more different scales and dimension it without getting actually disturbed by the confusion caused when dimensioning a single drawing that contains several scales. In fact, setting the displayed unit for a dimension is quite easy and simple to fix;
Just follow the above steps #1- 2 as it is, but at step #3 click on the Modify... button instead of the New... button, then go to the Primary Units tab and set the Scale factor located in the Measurement scale box as required and needed. (see Fig.5)
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| Fig.5- The Primary Units tab, Photo Source: www.101architechprojectsandblogs.com |
As an example of what was said, and assuming that we have an architectural plan presented within the same layout but as two separate views, each view is associated with a different scale than the other. The first view has a scale of 1:100, the other 1:20 (as metric units)
Our aim is to dimension the second view that has a scale of 1:20 as said before; All we have to do is to create a new dimension style that we will name dim-20, and based on the dimension style of the 1:100 scale drawing and already present in the same drafting sheet both.
So, getting to the Scale factor as described before, we will change it to a value of 0.2 instead of 1. As a result, we will get all the dimensions drawn with the style named dim-20 multiplied by the factor 0.2 set previously. As we can see the matter was fixed within no time and for good!
I personally appreciate this option which made the dimensioning process a piece of cake, whatever the issue is!
Furthermore, in addition to the above, it can represent different sorts of measurements, such as Structural Columns Grids, Architectural Partitions, and many others.
It is useful to note anyway, that turning on the Object Snap (F3) while taking dimensions will make the whole process definitively 100% accurate with zero percent errors or according to the range of errors permitted.
Different Types of Dimensions
Next, we will be listing the basic types of Dimensions available with the AutoCAD program, with a glimpse of each one:
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- Linear (horizontal and vertical): Provide linear distance or point-to-point measurements within a straight line, vertical or horizontal.
- Aligned: Provide linear distance between two points within the 2D plan, even if not vertically or horizontally positioned.
- Radial (radius, diameter, arc): For measuring radial and diameters lengths.
- Angular: As its name indicates, this type of dimension is used to measure the angles between lines.
- Continuous: When we have continuity in distances to measure, this is the proper type to use; it starts dimensioning from where the last point ended.
- Baseline: Likely to the previous one, but with a single base point. (See Fig.6 above for more clarification)
- Leader: This is a special type of dimension if we can say, with no aim of measuring but only labeling and noting drawings, such as detailed sheets or other types of drawings.
- Ordinate (Xdatum, Ydatum): Designed to display the IDs of a specific point, which is usually stored within the log files, regarding its actual X and Y coordinates related to the current WCS – World Coordinates System.