Mike Freeman

AutoCAD has been the most widely used CAD package for years, and its market dominance continues despite many available industry-specific packages. At some point, anyone working in a design role within the engineering or architecture sectors will have had to use this software and should have made steps to learn AutoCAD basics.

AutoCAD is a very complex piece of software, but users don’t have to know how to use every command. Though some AutoCAD experts have extensive command line knowledge, there are many more AutoCAD users who just know enough to get their work done. It is possible to learn only the tools you need to carry out a specific task and not go any further. This means that there is a multitude of commands that you may never use, but it’s also possible that you are missing out on some helpful commands that could speed up your workflow or make your life easier.

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Below, we list eight of our favorite commands that should be a part of everyone’s CAD toolset.

1. OVERKILL

Anyone who works with CAD files created by others will come across drawing files that are a complete mess at some point. There might be multiple lines on top of each other and duplicated items. If you try to delete a line, it remains there on the screen. Sometimes you need to delete the same thing a few times before it eventually disappears because there are multiple overlapping lines. 

If you are the type of CAD user who likes orderly and tidy drawing files, this can drive you crazy. In fact, you may find that you spend a large amount of your time tidying up other people’s work.

This is where the command OVERKILL is useful. You will be presented with a dialog box that allows the option to ignore certain properties such as color, layer, and so on. You can then choose to combine and optimize selected objects, as well as specify a tolerance in the OVERKILL command.

The OVERKILL tool is worth learning, especially if you work in CAD management and find yourself frequently correcting other people’s work.

2. CHSPACE

One challenging aspect of knowing AutoCAD is understanding how the drawing areas in Paper Space and Model Space interact. In particular, viewports can be tricky to learn and to use properly. As a result, some AutoCAD users might either create their title blocks in the Model Space and scale them up, or they might shrink their model in Paper Space.

Blueprint

The CHSPACE command will allow you to move objects between viewports or between Model Space and Paper Space with ease. But unlike cutting and pasting, the CHSPACE command changes the scaling so that the object in the drawing looks the same as before. Because the command allows you to move objects between spaces quickly, you’ll find it most helpful when creating legends and keys.

One thing that can confuse people about Paper Space and Model Space is the need to show items in different viewports on the same drawing or when showing items in both Model Space and Paper Space. This is especially true for indicative symbols rather than dimensionally accurate symbols. Ideally, symbols and dimensions should be the same size even if the viewports are at different scales. You might also like to see the same symbols or linetypes in a viewport and in a legend that is on your title block in Paper Space.

This can lead to issues as you struggle to get the various objects to look the same because of the difference in scale. You might have seen this before when looking at other people’s drawings where the objects on a legend or key don’t match the ones in the model. This can lead to confusion.

3. BURST

Most AutoCAD users are familiar with the EXPLODE command, which is used almost daily by CAD users who work with blocks. However, one issue is that when using EXPLODE on a block, any attribute text will revert to the default attribute value. This is almost always not what you want to happen, and it can be annoying and time-consuming to change all the text manually. 

This is where the BURST command is a time saver. When using BURST, all the text values will remain as they were within a block. This means that you don’t need to edit the text afterward, and the exploded or BURST block will look identical to when it was a complete block.

Another benefit of using BURST is that this command preserves block layers. When using EXPLODE, layers can change from the layer assigned to the block, and this can cause problems if using any form of layer control. Fixing this issue can be another time-consuming job.

Given the above advantages and that there are no real downsides to using BURST, it is a good habit to start using BURST instead of EXPLODE. Once you get into this habit, you will probably continue to use BURST instead.

4. RENAME

CAD Management is an important part of being a competent AutoCAD user. The way you structure your files can help show others that you know what you are doing in AutoCAD. We have all opened files created by others without CAD management experience. Working with these files can be challenging.

One of the most important aspects of a well-managed drawing is correctly naming all components, especially when creating a block or layer. If items such as blocks and layers are randomly named or named with the AutoCAD defaults, it can be very time-consuming to identify items. It might take hours to correct these drawings and individually rename items through the various properties dialog boxes.

This is where the RENAME command is helpful. After typing RENAME in AutoCAD, you will see a new dialogue box that shows a list of all of the items of a specific type. You can then rename the items in this dialogue box without having to change the properties of each object separately.

This RENAME command is especially useful when working on a large project involving drawings from subcontractors, or when you have to rename a bunch of items to comply with the project’s CAD standards.

5. FIND

Text is an integral part of any AutoCAD drawing. Even the best CAD artists in the world spend a lot of time editing simple text. While most of these text changes involve small changes and spelling errors, there are also many times where you need to change a particular word, phrase, or number that appears multiple times in the drawing. 

For example, a material change means all items specified as “wood” are now “metal.” Perhaps you have a color referenced throughout a drawing, and the color has changed. You might also be changing a design from “proposed” to “existing.”

In all of these cases, you would likely need to spend time looking through the drawing file, finding each reference, and changing the text. This is time-consuming, and it’s also possible that you might miss one or more references, which could lead to mistakes later.

With the FIND command, AutoCAD will automatically search through the drawing and find the words and phrases you specify. The command also allows you to replace a word with another. For example, you could tell AutoCAD to change all instances of the word “Red” to “Blue.” This dramatically decreases the time you need to make multiple text changes, and it also reduces the risk of overlooking items.

6. PURGE

When first created, a basic AutoCAD file will have a small file size — typically just a few megabytes. This is because the default file doesn’t contain styles such as linetypes, text, and so on. There are also no layers, blocks, or xrefs included — these are all loaded into the program as needed.

In the workplace, it’s normal for an existing file to serve as a base for a new drawing rather than starting from a blank file. This means that title blocks, layers, and styles are already loaded and set in the drawing file. This helps save time.

However, one of the problems is that drawing files can become very large. Your drawing file may only have a small model, but all the preloaded information in the background adds size to the file. The reason is that when you bring in an object from another file, you also bring in all of the styles and settings. But when you delete that object, that information stays in the background of the drawing and adds space to the file. This can lead to large file sizes that cause problems when emailing.

Using the PURGE command will help to reduce these file sizes. PURGE will delete all the unused blocks, layers, linetypes, and other attributes from the file. You can always select which objects to delete, but only items that are not in use can be removed.

PURGE can dramatically reduce file sizes and is always worth using this command before saving a file.

7. AUDIT

Anyone that has used AutoCAD for a while will have come across drawings that sometimes act strangely. Perhaps AutoCAD keeps crashing randomly or whenever you try to do a specific command. This can cause some files to seem unworkable, and it would take hours of trial and error to understand the problem.

Luckily, AutoCAD has its own tool that finds errors in drawing files and fixes them automatically. This is the AUDIT command, and it can help save the day when your file unexpectedly becomes corrupted.

It is outside of the scope of this article to try to explain what AutoCAD does when it audits a file, but it basically looks for any bad coding in the drawing and then uses pre-programmed intelligence to repair the file, resulting in, hopefully, no more crashes and errors. 

8. RECOVER

The previous two commands, PURGE and AUDIT, are part of a trio of AutoCAD tools that help keep your drawing files in good shape. The third command in this group is the RECOVER command.

The AUDIT tool will repair an open drawing that keeps freezing or crashing, but what if the file is so corrupted that you cannot open it at all?

This is when the RECOVER command is helpful. By running this command, you can select an unopened file. AutoCAD will then run the file through a series of tests, find errors, and try to repair those errors.

The RECOVER command has been a lifesaver for many over the years and has helped recover damaged files that took hours or even days of work.

Every AutoCAD user should know the eight commands above. Together, they can help speed up your workflow, manage your files, and handle any errors that you may come across. These commands are especially useful if you are trying to achieve AutoCAD Certification.

If you would like to learn AutoCAD, or already have some basic knowledge and wish to become more proficient, please check Udemy’s range of AutoCAD courses. From complete beginner through to photorealistic 3D rendering – Udemy has courses that cater to all levels.

Page Last Updated: September 2021

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