CAD Drafting: Dynamic Blocks with Embedded Fields

 

As you all know, blocks help to reduce file size and the time it takes to draft an object multiple times.Howdy to all AutoCAD users and explorers who are well-versed in the uses of  blocks and fields.

Today, AutoCAD blocks are becoming intelligent and flexible, acquiring new features and constraints. These can be controlled parametrically, and we call them ‘Dynamic Blocks.’

In this article, we do a taste test of a mixture of Blocks and Fields (a ‘Field’ being an intelligent text in AutoCAD which is self-updatable) that can help us to update both simultaneously.

Let the experiment begin! Let’s combine Blocks and Fields in a single AutoCAD play.

First create the geometry of your block with specific measurements and requirements. Here, we show the penetration/symbol for an HVAC unit.

Now, we add an Mtext (or single text) below the unit to denote the length and the width of an HVAC unit (6 x 4 is the length and width in the image below).

Before going into detail, let’s explain why we want to combine block and field. We are trying to place a single block with a linked field – i.e., we want to generate the length and width of the unit by stretching the block to the desired size.

Here you go:

Type the command, ‘field,’ select ‘Objects’ from field category pick the ‘Object’ from field names.

Then click ‘Select object’ to select the vertical line of the geometry.

Next, pick ‘Length’ from the property bar and copy the expression from the field expression tab.

Now, paste the expression in the text of the length entity (ex: 6), which you have added below the unit.

The same above procedure is used for the width – select the horizontal line of the geometry.

Now the simple text turns to intelligent text. The gray shading indicates the field: see the image below.

Create a block with the geometry and text. Define the block name, base point, and behavior. In this step, we need to focus on the geometry to constrain and specify its features.

To do this, click ‘Tools’ tab ‘Block Editor’. Then select the block from ‘Edit block definition.’ It will enter into the editing area where the ‘Block Authoring Palette & Block Editor’ toolbar is visible with block geometry.

Here, we are going to apply linear parameters with stretch action on both the length (y-axis) and width (x-axis) of the geometry. Select one of the linear parameters (ex: Distance 1) in the drawing area and then pick the ‘Value Set’ menu from the properties bar. Select ‘List’ from the dropdown menu for Dist Type. Add several distance values of the unit in ‘Dist value list’. Follow the same procedure for the second linear parameter (ex: Distance 2).

Now test the block by using the ‘Test Block’ button in the ‘block editor’ toolbar. Then, use the arrow grips to watch how it works.. The stretching of the block reflects the actual distance in field (after a regen command) as shown below.

Thus, our demonstration is successful.

Since there are many features in both dynamic blocks and fields, we’ve only covered a few of them. If you need to create some of your own with different features, start at this point. The dynamic blocks with fields will prove useful to you in our fast-paced world.

For further reading, go here: https://themagnumgroup.net/Blog/683/computer-drafting-tip-customizing-autocad-fields.htm

And if you need help with your CAD drafting, we can help you at http://themagnumgroup.net/

 

Cheers, and take some time to explore the technique described above!

Thank you,