- Dimension variables are special system variables stored with each
drawing to control the appearance of dimensions.
- -a dimension style is a collection of dimension variable settings that you save with a unique name in a drawing.
- -you can completely change the way dimensions appear by changing variable settings in a dimension style.
- Use dimension styles to standardize dimensions and conform to a particular drafting standard or office preferences.
Save your custom dimension styles in your custom template files so they are readily available to use in New drawings.
There are more than 60 dimension variables to consider which is beyond the scope of this module.
- -in this module you will learn about key variables and you will learn how to create & manage styles.
- -you can use AutoCAD Help to learn more about individual variables.
You can create and edit (manage) dimension styles in the Dimension Style Manager using the Dimstyle command.
Dimension styles defined in the active drawing (or used in Xrefs) are listed in the Styles list.
- -when you select a style in the style list you see a Preview of dimensions for the selected style.
- -a description also appears to show how the selected dimension style differs from the current style settings.
- -children and overrides of named dimension styles are listed under the parent style in a tree structure.
- -you can use many dimension styles in the same drawing file (each dimension object can be created using a different style).
New drawings created from scratch will always have the Standard dimension style by default.
- -the Standard style will probably not suit your application.
- -you may want to change several settings such as text style, precision, text height, arrow size, arrow type, etc.. It is not good CAD practice to change Standard.
- -you should create your own dimension styles and define them to your preferences instead.
- -you can create a new style based on Standard, give it a new name and change settings to your preferences.
Making New Dimension Styles
You create new dimension styles by picking the New button.
– then you can enter a new style name and make changes to dimension variables for the new style.
Changing The Current Style
When you create a new dimension style it will NOT be the current style unless you explicitly make it the current style.
– the current style name is listed in the upper left corner of the Dimstyle dialogue box.
– select the desired style name to make current in the Styles list and then pick the Set Current button.
You can also double-click on a name in the style list to make it the current dimension style.
– or select the current dimension style from a drop-down list in the Dimension toolbar.
To modify a dimension style you select it in the style list and pick the Modify button.
– the selected style does NOT have to be the current style.
– you use the same interface to modify a style as you use to make a new style (i.e. change settings in one of the six different tabs).
When you modify a dimension style, all dimensions in the drawing that use this style will be updated automatically to the new definition.
– if you do not want to change existing dimensions it might be safer to create a new style with the desired settings instead.
You can temporarily override some dimension variables of a dimension style to make a few dimensions with different settings.
– for example, you might change the precision for primary units to create a few dimensions with less decimal places.
– this is like creating dimensions using the named style settings and then using Properties to modify selected dimensions.
You would normally only use Overrides if you have several dimensions to create that are slightly different from the current style.
– if you plan to create these types of dimensions on a regular basis you should define a new named dimension style instead.
– you should NOT create an override and then leave it in effect (discard Overrides when you no longer need them).
When you create <style overrides> you see these changes updated in the Preview area
-and these overrides are listed in the Description area when you select <style overrides> in the style list.
-<style overrides> appears under the current dimension style on the style list in a tree structure.
You can ONLY create an override for the current style.
– the Override button is not available if you select other styles.
If you select a named style name & pick the Set Current button you will discard <style overrides> (if there are any overrides in effect).
-but you will be asked if you want to continue or cancel before the <style overrides> are discarded.
-if you right-click on <style overrides> in the style list you will invoke a shortcut to Rename, Delete or Save to current style.
Dimensions are created in the Model so you must adjust dimension feature sizes appropriately for the desired drawing scale.
Many dimension variables control dimension feature sizes.
Rather than changing all variables that effect the size of dimension features every time you use a different drawing scale
-you can change ONLY the DIMSCALE variable to compensate for changes to drawing scale.
-each variable relating to size (e.g. see list above) is multiplied by the value stored in DIMSCALE for the feature size in the model.
-the follow table shows how you can compensate for drawing scale by changing only DIMSCALE.
You can change DIMSCALE on the Fit tab of Dimstyle.
If you select Scale dimensions to layout (paperspace) AutoCAD will automatically scale dimension feature sizes for all drawing scales.
-this approach is the easiest way to create dimensions because you do not have to calculate DIMSCALE yourself.
-however, you must create dimensions in a Layout (when the status bar says MODEL) to use this approach.
-and the viewport display scale must be set for to the drawing scale before you create (or update) dimensions.
If you select Scale dimensions to layout (paperspace) you should lock the viewport at the drawing scale before making dimensions.
-make the desired viewport current and set the viewport scale to the final drawing scale using the Viewports toolbar.
-left-click on MODEL in the status bar (it should say PAPER)
-select the desired viewport border to make it highlighted.
-right-click in the drawing area to invoke a shortcut menu.
-select Display Locked + Yes to lock the display scale.
practice with dimension styles
- Close the drawing for the previous exercise if it is open.
- Open the T112_7.dwg drawing in your personal folder.
This drawing uses paper space layouts to document a simple coffee cup in 2D.
Dimensions were created using default variables of the “Standard” dimension style for drawings created from scratch using English default settings.
“Dim detail view” and “Dim main view” layers contain dimensions for the “detail” & “main” views respectively and these layers are frozen in the appropriate viewports.
3- Pick Dimension + Style to invoke the Dimension Style Manager. Pick the New button there.
4- The New Style Name will be “Copy of STANDARD” by default and it will be highlighted. Type Custom to replace this name and then pick Continue.
5- Change the Arrow size from 0.1800 to 0.125 and then select the Text tab to continue.
6- Change the Text height from 0.1800 to 0.125. Then pick the button next to the Text style drop down list.
When you click on you invoke the same dialogue box that you would get if you used the Style command at the command prompt.
– you do not have to terminate Dimstyle to create a new text style.
7- Pick the New button and enter Dimensions for the new text style name. Then pick OK to return to the Text Style box.
8- Select Arial as the Font Name. Pick Apply then Close to return to the Dimension Style Manager box.
You just created a new text style that has a more attractive font compared to the default Txt.shx used by the Standard text style.
– the current text style is not necessarily the text style used by dimensions.
– in the next step you will assign the Dimensions text style to the Custom dimension style that you are in the process of creating.
9- Select the Dimensions Text style and then select the Fit tab to continue.
10- Change the Scale for Dimension Features to Scale dimensions in layout (paperspace) and then select the Primary Units tab to continue.
When you use the Scale dimensions to layout (paperspace) feature you should lock the display scale of your viewports
– then you can be sure that the feature sizes (e.g. text height, arrow size, etc..) will be the same for all dimensions.
– the viewports in this drawing have already been locked.
11- Change the Precision to 0.000 and check Leading for Zero Suppression (satisfy ANSI standards for drawings in inches). Then pick OK to return to the main Dimension Style Manager box.
12- Pick the Set Current button with Custom selected. Then pick Close to the terminate Dimstyle.
In a few steps you have created a new dimension style called Custom that is based on the Standard dimension style.
– you changed the sizes of features (text height & arrow size) and used a more attractive text style for dimension text.
– you reduced the number of decimal places and suppressed leading zeros for dimensions smaller than 1 inch
– Custom is now the current style and would be used for any new dimensions that you create (while the Custom style is current).
13- Double-click in the large viewport to switch to model space and make this viewport the current viewport.
14- Pick Dimension + Update. Select all red dimension objects in this viewport and then press <enter> to complete this task. (you could use an implied Window to select all objects in this viewport if you prefer).
When you create new dimensions they are made using the current dimension variables which are saved in the Custom style right now.
– you can also Update existing dimensions to use the current dimension variable settings.
– in this exercise you will use the Update method to save time (you will not have to make the dimensions yourself).
15- Left-click in the small viewport to make this the current viewport. Then update the dimension objects visible in this viewport using the same technique as in the last step.
16- Zoom In for a closer view of the dimensions in both viewports at the same time.
All dimension feature sizes (e.g. text height) are the same even though these two viewports use different display scales.
-this is because you updated dimensions in viewports while you were in Layout1 and you selected Scale dimensions to layout.
-the dimensions in the detail viewport would be twice as large as the dimensions in the rest of the model in the Model tab.
The detail dimensions are on a different layer than the other dimensions in the main viewport.
-and these layers only appear in appropriate viewports because they have already been frozen in the other viewports.
-you will learn more about freezing layers in specific viewports in the Page Setup & Layouts document.
17- Save your changes to this drawing and Close the file.