by Martin Phelps
During the process of adding dimensions to a drawing, some dimension lines may overlap or cross other dimensions and objects.
This can make the drawing harder to read, as shown in Figure 1.
Figure 1. Overlapping dimensions.
Solution 1.
In much older versions of AutoCAD, users may solve this problem by “Exploding” the dimension and using the “Break” command to break the extension line.
However, DO NOT DO THE ABOVE, since this will remove the associativity between the dimension and the object. This means if the location and size of the dimensioned object is changed, the dimension will not update. This process will also separate the dimension into its individual components, “Lines”, “Text” and “Solid Hatch”, and the dimension definition points disappear.
Solution 2.
Instead of using the “Explode” command, the same result can be obtained by using the “Wipeout” command in conjunction with “Draw Order “. This is a better option, since this method keeps the “Associativity” between the dimensions and the object. The downside is it can become a bit messy and time consuming, and also may increase the file size if used repeatedly.
Solution 3 – The best option!
In more recent versions, to solve this problem, Autodesk added the “Dimbreak” command to AutoCAD, this is not a new command but one which can easily be overlooked.
The “Dimbreak” command is located in the “Dimension” panel of the “Annotate” tab as shown in Figure 2.
Figure 2. The Location of the “Dimbreak” command in the “Annotate” tab.
Once the command has been activated, select relevant dimension, confirm by pressing enter. The “Dimbreak” command will automatically appear to break the selected line, but the associativity between the dimension and the object is retained, as shown in Figure 3.
Figure 3. The result of using the “Dimbreak” command.
Note: - In Figure 3, if dimensions are positioned as above, or the “Continuous” dimension command is used, each dimension by default will have two extension lines and therefore the “Dimbreak” command must be applied to both dimensions to obtain the required result.
Although the command is named “Dimbreak” the dimension extension lines are not broken, just masked.
For example, if the dimension text which the “Break” is around, the “Break” will move with the dimension text, so the “Break” area is masked, the dimension extension lines will update considering the new location of the dimension text as shown in Figure 4.
Figure 4. Moving the dimension text.
If the drawing changes and the “Break” is no longer required, the break can be removed by selecting the “Break” command, then the dimension that has the break applied, and from the sub commands select remove. Alternatively select the dimension and then the “Break” command then select “Remove”, both options will remove the “Break”.
Additional Options within the “Break” command.
When the command is initiated, there is an option “Multiple”; this will allow a number of dimensions to be selected, the “Break” can then be applied to all selected dimensions. It saves having to “Break” one dimension at a time.
Once a dimension has been selected for “Breaking” there is a “Manual” option, allowing the user to specify two points for the “Break”, overriding the set “Break” distance.
Notes: -
The “Break” distance is set with in the “Dimension Style”.
The “Break” command can also be used to “Break” the lines of “Multileaders”, again the “Break” distance is set with the “Multileader Style”.
Using the “Dimbreak” command gives clarity to the drawing making it clearer and easier to read.