Using the Annotative property to size dimensions - AutoCAD Tutorial

Just like with text, dimensions can also be annotative, this means we never have to guess when it comes to sizing the dimensions we place in a drawing. In this lesson, we'll use the annotative property to create some predictably sized dimensions. On my screen I have a conceptual design for an AM/FM clock radio. I have created a layout for this drawing, let's click the layout tab and take a look. This layout is configured for an eight and a half by 11 inch sheet of paper. I have already cut a viewport in the layout. And I've left the viewport edge turned on. If I zoom in you can see that the geometry is being displayed in this viewport at half scale. Let's do a zoom extents and we'll return to model space. I would like to add some dimensions to this drawing. Just like when we create text it's a good idea to wait on your dimensions until you know the size your geometry's going to plot. Now that we know the scale, one to two, we're ready to create dimensions. If you look at the layer control you can see I'm practicing good form. I've created a layer for my dimensions. The next thing I'm going to do is create a dimension style. I will do that by opening the Annotation panel and I'll click the dimension style icon. I'll select New and I'll call this style Annotative Dims. Initially their settings will match the standard dimension style. I'm going to come down and put a check in the Annotative box. By making the style annotative AutoCAD will do all the work when it comes to sizing these dimensions. Let's click Continue. It's important to note that when you create an annotative dimension style, any of the size settings that you see in this dialogue box, you will set to the size you want that object to appear when printed. I'm going to start by going to the Lines tab, and I'll change the extension line distance to 0.10. We'll go to symbols and arrows. And I'd like the arrowheads to be a little smaller. So I'll change this to 0.125. We'll go to the text tab. I'll make the text height a little smaller, 0.125. Finally, I'm going to go to the primary units tab. And I'll set the precision for these dimensions to be two decimal spaces. When I'm finished, I'll click OK. If we look at the dimension style, you can see the addition of the annotative icon, so we know these dimensions will scale automatically. I'll click close when finished. Since I'm working with an annotative style, whenever I create dimensions AutoCAD is going to look right here to set the size. So I'll open the view port scale and I'll set this to one to two, same scale that I'm using in my view port. I will then create a linear dimension. We will dimension the overall length of the part, so I'll start from the quadrant at the top and we'll dimension to the quadrant at the bottom. If I drag this over, you can see that the dimension appears to be properly sized for a half-scale plot. I would also like to create a dimension that represents the overall width. We'll go from the quadrant on the left side to the quadrant on the right, and I'll pull this out. And click. Now that I'm finished we'll go back to the layout tab and take a look. As you can see these dimensions are very easy to read, they are properly sized for this plot. Let's try something else now. I'm going to create a copy of this view port. I'll launch the copy command and select the view port edge. I will pick it up from a point on screen here. And I'll drag the copy over here to the right. When I'm finished I'll press Escape. Now that I've created a copy, you can see that geometry in this view appears using the layer color. What I'm going to do is type R E A and press Enter. That stands for regen all. That will regen not only the contents of the layout, but model space as well. So now the geometry is assuming the pen colors. Let's create a detail of this switch. To do that, I'll double-click in the view. I'll come down here and unlock it and then I will roll my wheel forward. We'll zoom in on this geometry. Then we can come down to the scale list, and try and find a usable scale. Let's try two to one. That's not too bad, I think we can try four to one, might work better. That's perfect, the switch is now being displayed four times its normal size. I'll lock the view port again, I will double-click outside the boundary to get my cursor back on the lay out. And then I am going to click the viewport edge and I'll adjust the grips slightly. I'm being mindful of my running object snaps. If I hold F3 down I can disable the running object snaps until such time as I take my finger off the F3 key. I'll drag this corner up and click. When I'm finished I'll press Escape, and then we'll return to model space. Now, let's apply some dimensions to the switch. First thing I'll do is come down and change the annotation scale to four to one. I'll launch the dimension command, and we'll do the overall length from the quadrant here to the quadrant here. Let's do the width as well. I'll select end point to end point and pull this out. I'll press my space bar to relaunch the command and I will dimension the width of this tab. Finally I'll click to select the last dimension. I'll hover over this number and select Move Text Only and we'll put the 13 above the dimension line. That looks good. When I'm finished I'll press Escape. We'll go back out to the layout. Once again, notice the dimensions are perfectly sized for this view. If you use the annotative property, you never have to worry about the size of your dimensions. One more thing, I don't know if you noticed this, take a look at this view. Notice that those dimensions don't show up over here. If I double-click in this view port, and hover over this geometry, you can see that it's the same geometry in both views. Let's double-click back out. If you use the annotative property, your annotations will only show up in the view port for which they were intended. Now that I'm finished setting up my drawing I am going to copy the scale label. I'll pick it up from a point on screen here and I'll place it next to the detail. I will then double-click and edit the text. We'll make this four to one and when I'm finished we'll zoom out and turn off the view port edges. Since the view ports are on their own layer, I can do that very easily using the layer control. As you can see, if you assign the annotative property to a dimension style, you will always have predictably sized dimensions on your plots. Not only that, the annotative property also guarantees that only the appropriate annotations will display in each view port.