AutoCAD 2005 for Dummies

	REVCLOUD	Arc length	Revcloud	Revision Cloud
	DOnut	Inside, outside diameters	None	Donut
	SPLine	Convert polyline or create new	Spline	Spline
	ELlipse	Arc, center, axis	Ellipse	Ellipse; submenu for definition methods
	POint	Point style	Point	Point; submenu for definition methods

  Many of the choices on the AutoCAD Draw menu open submenus containing several variations on each drawing command.

The AutoCAD drawing commands depend heavily on your reading the command line area and sometimes typing things there. Don’t worry; I remind you to do so. (If “command line area” sounds to you like a place to order cafeteria food, not an AutoCAD essential concept, see Chapter 2.) Many of the command options that you see in command line prompts are available as well by right-clicking in the drawing area.

  So what’s the best course: to enter drawing commands from the command line or to choose them from the menus or toolbars? I suggest that you start a drawing command the first few times — until you remember its command name — by clicking its button on the Draw toolbar. After you click the button, fasten your eyes on the command line area so that you see the name of the command and its command line options. Use the keyboard or the right-click menus to select options, depending on whether your hand is on the keyboard or the mouse at that moment. After you’re acquainted with a drawing command and decide that you like it enough to use it often, find out how to type its keyboard shortcut (the uppercase letters in the command names in Table 5-1).

  A few drawing commands, such as DOnut, aren’t on the Draw toolbar; you have to type those or choose them on the Draw menu.

The Straight and Narrow: Lines, Polylines, and Polygons

As I harp on a bunch of times elsewhere in this book, CAD programs are for precision drawing, so you’ll spend a lot of your AutoCAD time drawing objects composed of straight-line segments. This section covers these commands:

? Line: Draws a series of straight line segments; each segment is a separate object

? PLine: Draws a polyline — a series of straight and/or curved line segments; all the segments remain connected to each other as a single object

? RECtang: Draws a polyline in the shape of a rectangle

? POLygon: Draws a polyline in the shape of a regular polygon (that is, a closed shape with all sides equal and all angles equal)

The following additional straight-line drawing commands also are available in AutoCAD:

? RAY: Draws a semi-infinite line (a line that extends infinitely in one direction)

? XLine: Draws an infinite line (a line that extends infinitely in both directions)

  The RAY and XLine commands are used to draw construction lines that guide the construction of additional geometry. Drawing construction lines is less common in AutoCAD than in some other CAD programs. AutoCAD’s many precision techniques often provide more efficient methods than construction lines of creating new geometry.

Toe the line

The Line command in AutoCAD draws a series of one or more connected line segments. Well, it appears to draw a series of connected segments. In fact, each segment, or piece of a line with endpoints, is a separate object. This construction doesn’t seem like a big deal until you try to move or otherwise edit a series of segments that you drew with the Line command; you must select every piece separately. To avoid such a hassle, use polylines, described later in this chapter, not lines and arcs when you want the connected segments to be a single object.

If you’re used to drawing lines in other programs, you may find it confusing at first that AutoCAD’s Line command doesn’t stop after you draw a single segment. AutoCAD keeps prompting you to specify additional points so that you can draw a series of (apparently) connected segments. When you’re finished drawing segments, just press the Enter key to finish the Line command and return to the Command prompt.

Unlike a lot of AutoCAD drawing commands, Line doesn’t offer a bunch of potentially confusing options. There’s a Close option to create a closed polygon and an Undo option to remove the most recent segment that you drew.

  Like all drawing commands, Line puts the line segment objects that it draws on the current layer, and uses the current color, linetype, lineweight, and plot style properties.

? Make sure that you’ve set these properties correctly before you start drawing. (I recommend that you set color, linetype. lineweight, and plot style to ByLayer.) See Chapter 4 for information on setting the current properties with the Object Properties toolbar.

? When you’re doing real drafting as opposed to just experimenting, make sure that you use one of AutoCAD’s precision tools, such as object snaps, typed coordinates, or tracking to ensure that you specify each object point precisely. Chapter 4 describes these tools.