AutoCAD For Dummies. Ralph Grabowski

      FIGURE 3-6: Give the column some thickness with OFFSET.

      

Now that you’ve given Dynamic Input a test drive, turn it off for the rest of this chapter by clicking its button on the status bar so that the button looks dimmed or by pressing F12. If you like using Dynamic Input, toggle it back on.

      The drawing afd03b-i.dwg contained in the afd03.zip download includes the base plate and column and one anchor bolt.

Taking a Closer Look with Zoom and Pan

      The drawing example in this chapter is uncluttered and manageable, but most real CAD drawings are neither — technical drawings are usually jam-packed with lines, text, and dimensions. CAD drawings are often plotted on sheets of paper that measure 2 to 3 feet on a side (in the hundreds of millimeters, if you’re a metric maven). Anyone who owns a monitor of that size probably can afford to hire a room full of drafters and therefore isn’t reading this book. You need to zoom and pan in drawings — a lot. I cover zooming and panning in detail in Chapter 5. These quick definitions should suffice for now:

       Zoom: Change the magnification of the display. When you zoom in, you move closer to the drawing objects so that you can see more detail; when you zoom out, you move farther away so that you can see more of the drawing area. Zooming does not change the size of the objects in the file. You can think of zoom in AutoCAD like the zoom function on your camera: You get closer, but you see less.

       Pan: Move from one area to another without changing the magnification. If you’ve used scroll bars in an application, you’ve panned the display. Panning does not change the location of objects in the file.

      Frequently, zooming and panning let you see details better, and draw more confidently because you can see what you’re doing, and edit more quickly because object selection is easier when a bazillion objects aren’t on the screen.

      Fortunately, zooming and panning in AutoCAD are as simple as they are necessary.

      

If you have a wheel mouse, you can zoom by simply rolling the wheel back and forth. To pan, press and hold the wheel (yes, the wheel is also a button) and drag the view around. These actions can be performed even when another command is active. If you don’t have a wheel mouse, run out and buy one. The small amount you’ll pay ($20 for cordless or $5 for a USB corded version) is easily recovered by your new operating efficiency. (Disclaimer: I have no financial interest in any mouse company or wheel company.)

      Meanwhile, until you buy a wheel mouse, check out Chapter 5 to see how to use AutoCAD’s Zoom and Pan Realtime features.

      

The fastest way to return to a full view of the entire drawing is to type, at the command line Z A, which is short for Zoom All. Note the space between the two letters, and remember to press Enter or the spacebar after you type each letter.

Modifying to Make It Merrier

      When you have a better view of the base plate by zooming, which I talk about in the preceding section, you can edit the objects on it more easily. In the following few sections, you use the Hatch command to add crosshatching to the column and use the Stretch command to change the shape of the plate. As always, I cover these commands in detail later in this book.

      The drawing afd03c-i.dwg contained in the afd03.zip download adds the remaining anchor bolts.

      Crossing your hatches

      The next editing task is to add crosshatching to the space between the inner and outer edges of the column. The hatch lines indicate that the drawing shows a cross section of the column. To do so, follow these steps:

      1  Turn off Object Snap (F3), Ortho (F8), and Snap (F9) modes by clicking their respective buttons on the status bar or by pressing the indicated function key until the icons look dimmed.

      2  Select the Hatch layer from the Layer drop-down list at the top of the Layers panel on the Home tab.

      3  On the Home tab’s Draw panel, click the Hatch button (shown in the margin) or type Hatch at the keyboard.The Hatch Creation tab appears on the Ribbon. For more information on this tab, and on hatching in general, see Chapter 15. Note that the Ribbon now has a light blue line around it and all the panels now show actions related to creating and formatting crosshatching.

      4 On the Hatch Creation tab’s Pattern panel, select ANSI31.Depending on your screen resolution, the panels may show more or less information. If you don’t see an ANSI31 sample swatch, click the down arrow at the bottom of the lower-right corner of the Pattern panel. A scrollable list of all available patterns will appear. The ANSI31 swatch is the American National Standards Institute (ANSI) standard pattern number 31 (ANSI 31) and not ANS 131. Move the cursor over the drawing objects.A live preview shows you the result if you click at the current crosshair position. AutoCAD prompts you:Pick internal point or [Select objects/Undo/seTtings]: Move the cursor so it's between the inside and outside edges of the column. Zoom in if you need to get closer.The live preview shows the ANSI31 hatch pattern filling the space between the two filleted rectangles. Live preview not only shows you the pattern but also lets you preview the hatch angle and scale. In this case, it looks like the hatch pattern may be too fine.In the Scale window in the lower-right corner of the Hatch Creation tab’s Properties panel, change the value to 5 and press Tab to confirm it.Move the cursor back to the area between the two filleted rectangles to preview the hatch again. If it looks okay, click in the hatched area to confirm the hatch object, and then press Enter to finish the command.The finished column and base plate should look much like the one shown in Figure 3-7.

      Perfect! But suppose that the nutty engineer (hey, I resemble that remark!) has decided that the column needs to measure 18 x 18 inches rather than 12 x 18 inches. Therefore, the base plate is too small, and the anchor bolts are in the wrong place. If you were drafting from paper on the drawing board, you’d pull out the eraser right about now to rub out half your effort — and if you were lucky, you’d have an electric eraser. At some point, you simply tore up the paper and started over, or labeled the appropriate dimensions as NTS (Not To Scale). It’s AutoCAD to the rescue.

      FIGURE 3-7: Button-downed base plate.

      Now that’s a stretch

The Stretch command is powerful: It can stretch or move objects, or stretch some and move others at the same time, depending on how you select them. The key to using Stretch is specifying a crossing selection box properly. Chapter 10 gives you more details about crossing selection boxes and how to use them with the Stretch and other editing commands.

      

Begin with the drawing from the previous section open in AutoCAD, or open the file afd03c-i.dwg contained in the afd03.zip download.