So you’ve made the first step to an immediate increase in AutoCAD efficiency by creating your first block. Let’s say you’re an architect, and you’ve created a block represented by a door that you can now quickly add to all your entryways. This works perfectly — until that door you created for the 2nd floor bedroom doesn’t fit in the open space left for the front door. Instead of drawing another door to fit this space, this problem can be overcome through the use of dynamic blocks. In this guide, I will take you step-by-step through the process of creating dynamic blocks, which you will undoubtedly find useful.
What Are Dynamic Blocks in AutoCAD?
Dynamic blocks introduce a new level of customization to your standard block. Blocks allow you to utilize repetitive geometry in your drawing, whereas a dynamic block allows you to manipulate specific features of the block. This makes real-time design changes quicker and easier. Dynamic blocks are ideal for scenarios where an object will appear in various sizes or configurations within your drawing.
Some practical examples of dynamic blocks:
A door in an architectural drawing
Linear and rotation parameters can be added to allow for editing the position and orientation of the door respectively.
Windows and furniture
Stretch, flip, and rotation actions can be added to furniture blocks for quick edits to size and orientation.
Creating a Dynamic Block in AutoCAD
The path to using dynamic blocks begins with creating standard AutoCAD blocks. The steps below will help you get started by using the example of a simple rectangle. Before following the guide below, make sure you’re creating your block in Layer 0.
Begin by drawing the rectangle using AutoCAD’s drawing tools.
Navigate to the Insert tab found in your top ribbon and click Create Block.
The Block Definition dialog box will appear.
This is where you will name your block (e.g. door, table, chair, etc.) and select your basepoint. You can always rename the block
Click the Pick Point button to select your basepoint (corner or center of your shape).
Note, if you do not select a basepoint, the block insertion point will default to 0,0,0 coordinates on your drawing.
Under the objects column of the block definition dialog box, you will want to Select Objects.
Upon clicking this, the dialog box will be hidden, and you will need to highlight the entirety of your shape.
Finally, select either Retain, Convert to block, or Delete under the objects column.
Retain will keep the object block in its original elements (shapes, arcs, etc.).
Convert to block saves the highlighted objects as a consolidated piece.
Delete will save the block to your library and then remove the block from the space in which you’ve drawn it.
Press OK to save the block to your library and allow the block editor to be opened.
If the block editor does not open, simply right click on your block and find the block editor option on the drop-down menu.
Dynamic Block Parameters
We will now explore converting your block to a dynamic block. There are several parameters shown in the block editor (block authoring palette). For now, we will focus on movement and rotation parameters.Parameters and actions in combination will allow you to manipulate your block as a dynamic block.
Adding Movement Parameters
For this scenario, you will be moving your shape along the x-axis. Begin by selecting the Linear Parameter from the block authoring palette. Because we are repositioning the shape on the x-axis, select the top-left, then the top-right corners of your shape. From here, you can close the block editor and save your changes to reveal the linear parameter line.
If you have you have your Properties Tab visible, you will see a variety of options that can be edited. Under the Value Set tab, you can manipulate how you want the movement parameter to affect your shape. If you have it set to “None,” you will be able to freely move the shape. Alternatively, the “Increment” option will allow you to move the shape in set amounts along the x-axis. Also in the properties tab is the Number of Grips. Grips are the vertices of the linear parameter. You will likely have two grips, which will allow you to move the shape in either direction on the x-axis.
Now that we have our linear parameter in place, it is time to add an action. In this case, the Move action will be selected. Select Move from the actions tab of the block authoring palette, then click on the linear parameter line. The final step for this action is to select all parts of the block that you want to move. Since we want the whole shape to move, highlight your shape, then press enter. At this point, you may want to test the block before adding any more parameters. Select Test Block from the top ribbon, and make sure your movement action is operable.
Adding Rotation Parameters
Let us now take our shape and add a rotation parameter. This will allow us to quickly rotate our block around a specified point. To begin, find Rotation in the parameters tab of the block authoring palette. The first step is to choose a basepoint. I find it best to use the same basepoint you used when creating the block (corner or center of shape). The basepoint you choose will dictate the axis at which your shape will rotate.
Once your basepoint is chosen, a circle will appear with your basepoint at its center. The point you choose will determine the location of the grip you will use to later rotate your block. We will then be asked what the default rotation for our block will be, which in this case we will set to 0 by pressing enter. AutoCAD will then ask how many grips are desired for rotation. To keep things simple, press enter to use the default setting of one grip.
Let’s now find ourselves back at the block authoring palette and navigate to the actions tab again. This time, we will select the Rotate action. Left click on the grip created from the Rotation Parameter to be further prompted to highlight the object(s) that you want to rotate. For our example, you will select your object and press enter. Close the block editor, save your changes, and test the block. Because there are now two dynamic parameters, you will see two grips. You will be pleased to see that you can now move your shape along the x-axis, as well as rotate it to your liking.
Summary of Dynamic Blocks
Following this guide to create simple dynamic blocks is your first step in tackling your day-to-day headaches in AutoCAD. Stretch, scale, flip, and alignment are additional parameters that I encourage you to experiment with once you become comfortable with the basics of dynamic block parameters. With the help of this guide and other resources on our site, the addition of parameter-action combinations to create dynamic blocks is sure to streamline your AutoCAD workflow exponentially.
In engineering drawings, dimension lines are lines that indicate the many measurable features in your drawings. They define the size, shape, and placement of items in the drawing and are necessary for accurately communicating design specifications.
Dimension lines are a key part of how the drawing will be read and understood by your reader, ensuring all important details cannot be misinterpreted. Without dimension lines, a finished drawing is simply a print-out of random lines and shapes!
Essential Components of Dimension Lines
Dimension lines should not be confused with other visible lines in your drawing. Dimension lines contain specific features to differentiate themselves. Below you will find a list of features that will allow you and the reader to distinguish dimension lines from other items in the drawing.
Numerals
Dimension lines show numerical annotations that specify the exact measurement of a feature, such as length, width, height, angle, etc. This value is typically found at the midpoint of the line, formatted according to the drawing’s unit system (mm inches, degrees, etc.). Tolerances (±0.2mm) may be added to indicate acceptable variation in the finished part. Sometimes, symbols like Ø for diameter or R for radius can be used. Dual dimensions (2.54 cm [1 in]) show both metric and imperial units for multipurpose uses.
Extension Lines
Extension lines are thin lines that extend from the object you wish to measure to the dimension line, showing exactly what points are being measured. They begin just outside the object’s edge, with a small gap, and don’t touch the measured object directly to avoid clutter. Extension lines improve clarity by linking dimensions to specific features. Note that it’s important to avoid intersecting extension lines with other features in the drawing to avoid confusion.
Arrowheads
Arrowheads on dimension lines mark the endpoints of a measured distance or angular dimension. They are usually small, filled triangles but can vary in style depending on your drawing specifications. Arrowheads allow for precise measurement boundaries and are typically sized proportionately to the line to prevent crowding the drawing.
Types of Dimension Lines in Engineering
In engineering drawings, there are multiple different dimension lines that all serve a different purpose. You will likely use most, if not all, of these different types once familiarized. You will find a description of several of these linetypes below. The visual snippets in the table are taken from the AutoCAD dimension drop down.
Measurement
Description
Visual
Linear
Measures straight horizontal or vertical measurements such as length, width, and height
Aligned
Runs parallel to the feature being measured
Useful for measuring the true length of slopes or other diagonal features in a drawing
Angular
Indicates the angle between two lines/objects
Particularly useful for drawings with sloped or objects that have been rotated
Arc Length
Measures the arc length of rounded features
Useful for obtaining the true length along a rounded segment
Radius
Provides the distance from the center of a circle or arc to its perimeter
Contains the prefix, “R”
Diameter
Measures the full width of a circle as a centerline
Contains the prefix, “Ø”
Jogged
Most useful for large circles or arcs
Similar in appearance to the radius line, but with a zig-zag pattern
Great for providing radius measurements without crowding your drawing
Ordinate
Provides X or Y coordinates of a point relative to the selected origin
Useful for noting precise locations in a layout drawing that may be used for CNC or machining
Practical Applications of Dimension Lines in Engineering Design
Now that you have become familiar with the different dimension linetypes and how they differ from other items found in your drawing, I’d like to take you through some examples of where you might use them. Understanding where and when to use these different dimension lines will be pivotal in your design journey.
Linear Dimension Lines
Linear dimension lines are generally the most common in engineering drawings, applied wherever straight (horizontal or vertical) distances need to be measured. One example would be if you are defining the basic dimensions of a rectangular part, like a window. Each side of the window will have a linear dimension, specifying exact dimensions for manufacturing. This ensures that parts will fit properly, and installation issues can be avoided.
Aligned Dimension Lines
Aligned dimension lines are ideal for measuring diagonal or sloped elements, providing true-length measurements along the feature. For example, the length of a chamfer on a steel rod would be measured with an aligned dimension. This type of dimension is also helpful in architectural drawings, where a sloped staircase would need to be measured.
Angular Dimension Lines
For angular dimension lines, let’s use the example of a gear teeth or a spline shaft used in industrial equipment. The angular measurements of the gear teeth and shaft are critical dimensions. Smooth operation of the assembly will rely heavily on proper dimensioning in the drawing. Proper tolerancing of these dimensions will also directly impact part performance.
Arc Length Dimension Lines
A practical use-case for measuring an arc-length could be custom ductwork in an architectural floor plan. Ensuring accurate dimensioning of the curved metal piping will be crucial during installation. Another example could be measuring the curved elements of metal conduit in an industrial floor plan.
Radius Dimension Lines
Radii in engineering drawings are incredibly important. Take for instance designing metal casting molds for vehicle engine parts. Sharp corners that would be produced without proper radial dimensioning act as stress concentrators once in service. Stress concentrations in critical components can lead to catastrophic failure of high-value components in an assembly.
Diameter Dimension Lines
Diameter dimensions become more important when dealing with cylindrical features such as pipes or holes in a drawing. To be more specific, the diameter of a hole to be drilled for a fastener needs to be properly defined to ensure precise fit during assembly. The tolerances on diameter dimensions will also be a specifically important annotation to keep in mind.
Jogged Dimension Lines
As previously mentioned, jogged dimensions are exclusive to features with a large radius. For example, the large arcs that would need to be defined on an arch bridge. The jogged dimension will provide the radius measurement but with a shorter, zig-zag dimension line to avoid clutter in the drawing. Civil engineers commonly use jogged dimension for their large-scale features.
Ordinate Dimension Lines
After specifying an origin, ordinate dimensions allow for exact placement along the X and Y coordinate system. Commonly seen in critical dimension applications such as circuit boards for electronics, ordinate dimension lines provide accurate placement of all features. This dimensioning style prevents cumulative errors and makes it easy to work with complex drawings that rely on perfect placement.
Measuring angles in AutoCAD is an essential tool that every user should master. Technical drawings, floor plans, and mechanical components, etc. all contain angles that need proper measurements to ensure accuracy and precision in the finished drawing.
In this article, we will walk you through the step-by-step process of measuring angles in AutoCAD. Whether you’re a beginner looking to learn a new skill or a seasoned user needing a refresher, this guide will ensure you have the knowledge needed to properly measure angles in AutoCAD.
Understanding the Basics of Angles in AutoCAD
AutoCAD offers various tools and commands, such as the Measure and Angle commands, to help you define and calculate angles accurately. Some angle examples in your drawing that you may want to specify include:
Interior angles of a shape
Rotation angles of a shape or object
Angles between two lines or shapes
Angular dimensions of a previously drawn polyline
Practical Steps to Measure Angles in AutoCAD
Measuring angles in AutoCAD is fairly straightforward when you know the right tools and commands to use. Below are step-by-step instructions for properly and efficiently measuring angles between lines, objects, or points in your AutoCAD drawing.
The 1st command we’re going to cover is the Measuregeom command. This command works for measuring several dimensional properties of objects, but for this example, we’re obviously focused on angular dimensions. Measruregeom displays the measured angle in the command line but won’t annotate the drawing by default.
Let us begin by drawing a simple 6-sided polygon.
Once drawn, type “mea” to select the Measuregeom command from the dropdown list.
You will then want to select angle from the command window that appears.
Select a starting point, which in this case will be one of the sides of the polygon.
Select the end point, which will be another side of the polygon – Note, your start and end point selections will determine the vertex for your angle.
You should now see the angle measurement between the two lines you have selected.
The 2nd command commonly used to measure angles is Dimang. Dimang is used exclusively for measuring angles between drawn lines and/or objects. The difference between Dimang and Measuregeom is Dimang displays the angle measurement on your drawing as part of the final layout.
You can use the same shape as the first example.
Type “dim” in the command line and select dimangular from the drop-down menu.
Select your start and end points the same way as we did for Measuregeom.
You will notice this time that the annotation format is different. This is because Dimang is embedding the angular dimension into the drawing to be visible in the finished product.
Troubleshooting Common Issues in Angle Measurement
The steps to measuring angles is simple, however problems can arise for a number of reasons. Some common issues that you may encounter could include the following:
1. Angle Orientation Issues
If the angle measurement shown visually seems completely off, double check your drawing’s user coordinate system (UCS).
The default angle orientation in AutoCAD has 0° pointing to the right with increasing angle measurements in the counterclockwise direction.
2. Issues with Object Selection
If you’re finding yourself struggling to select lines or objects, you can always zoom into the drawing for better accuracy.
Also, it’s important to make sure that objects of interest are not locked or part of hidden layers.
3. Incorrect Display Units
Let’s say you want to display your angle in degrees, but you are seeing radians. Check your units setting using the Units command and verify that the desired units are selected.
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