AutoCAD software package is a system that allows you to automate drawing and graphic work. AutoCAD is a software package from Autodesk, which is computer-aided design system (CAD). The main advantage of AutoCAD is the availability of creating powerful specialized computational and graphic packages on its basis. In the AutoCAD system, it is possible to develop two-dimensional drawings and drawings, as well as surface and volumetric (solid) structures in various fields of human activity (engineering, construction and architecture, etc.). This methodological guide will consider the AutoCAD 2007 package. All versions of the AutoCAD system are interconnected by a single data storage format and are designed to work in the Microsoft Windows operating system (starting with the Microsoft Windows 95 operating system). The main advantage of the AutoCAD system is the possibility of the subsequent formation of an electronic archive of drawings. Each of the files and drawings created in this way can be easily edited, which allows you to quickly get analogous drawings from prototype drawings. To facilitate the process of issuing design documentation, you can develop "libraries of standard elements". Both whole files and their separate parts can act as standard elements. Starting with AutoCAD 2002, the system includes special tools for controlling enterprise standards, allowing you to manage layers, styles, etc. A powerful addition to this is the ability to use programming languages. The AutoCAD system has a built-in compiler for the AUTOLISP language, which allows the user to expand the capabilities of the system, as well as tools for developing applications in the C programming language. the user, providing a connection of graphic objects with external databases, allows you to view and copy drawing components without opening its file, edit xrefs and blocks located in external files, and much more. Computer requirements differ depending on the software version. For each newer version of AutoCAD, the computer requirements become more stringent. So, AutoCAD 2000 requires a processor not worse than Pentium 133 Mhz, the recommended memory size is 64 Mb (minimum - 32 Mb), hard disk - at least 130 Mb of free space, 50 Mb of free disk space in the system directory, at least 64 Mb in swap file. The design system itself takes about 150 - 190 Mb (depending on the installation option). A mouse is required, an SVGA monitor with a resolution of at least 800x600. For AutoCAD 2007, you need a computer of at least Pentium III 800 Mhz (better than Pentium IV), at least 256 Mb of memory (better than 512 Mb), and a hard drive of at least 2 Gb. Microsoft Windows 2000 (SP4) and Microsoft Windows XP (SP2) are the recommended operating systems.

Graphic primitives (point, segment, circle, etc.), commands for editing them (erasing, transferring, copying, etc.), commands for setting primitive properties (setting the thickness, type and color of graphic objects) correspond to manual drawing tools in an automated environment. ... To select a sheet of the required format and scale of the drawing, the system has the appropriate setup commands. To apply a dimension, you just need to specify its location in the drawing. Dimension and extension lines, as well as arrows and labels are executed automatically.

AutoCAD commands allow you to enlarge the image of a drawing on the screen or reduce it if necessary, as well as move the boundaries of the part of the drawing visible on the screen without changing the scale of the image.

The system provides the ability to combine graphic objects into a single block, which is stored under a specific name and, if necessary, is inserted into any drawing. It is possible to create images of individual elements of the drawing or individual parts of an assembly on different layers. This allows you to control the compatibility of parts during layout. By turning layers on or off, you can enter or remove parts from the general layout, thereby creating convenience in the selection of various options for the design of the product. It is useful to use layers even in simple drawings, placing on each separate layer a drawing blank, strokes, dimensions, labels, centerlines, for the subsequent possibility of quickly selecting a group of objects and editing them.

In addition to creating 2D drawings, AutoCAD allows you to model 3D objects and give 3D drawings a photographic reality.

Basic terms. AutoCAD commands are formed in the process of accessing menus and toolbars and represent a sequence of subcommands that are selected in each successive submenu. Calling commands and entering graphic elements is carried out using the mouse or keyboard.

Terms used when describing the mouse in AutoCAD:

· cursor- mouse pointer on the screen (the type of the cursor can change, taking the form of either a crosshair, or a small square (sight), or an arrow, or a hand);

· aim- a small square used when selecting objects in the graphics area;

· point out- move the cursor to the graphic object and click the left mouse button;

· choose- move the cursor in the shape of an arrow and click on a menu item, a toolbar icon or a dialog box control;

· click- press and quickly release the mouse button (usually the left one);

· double click- quickly perform two clicks;

· stretch out- move the cursor followed by the graphic object;

· click and drag- press the left mouse button and, without releasing it, move the cursor, following which the selected object will move across the screen.

Entering the AutoCAD environment. Launching AutoCAD in the Microsoft Windows operating environment is carried out, for example, by the command Start → All Programs → AutoCAD → AutoCAD 2007 (Start → Programs → AutoCAD → AutoCAD 2007).

After loading, a dialog box will appear on the screen. 2 types are displayed in the main menu bar Workspace:

· 3D Modeling(new type of space, optimized for 3D modeling);

· AutoCAD Classic(classic workplace).

After selecting the type of workspace, a graphical user interface ( Graphical User Interface - GUI) (fig.2.1):

Rice. 2.1. AutoCAD 2007 Graphical User Interface

Graphical interface. There are four functional areas on the screen:

· Working graphics area- a large area in the middle of the screen where the drawing is executed. In the lower left corner of the zone there is a custom coordinate system icon. The directions of the arrows coincide with the positive direction of the axes.

· System menu and toolbars. At the very top of the screen is the header line with the file name (by default Drawing1). Directly below it is the AutoCAD system menu bar. Below there are two lines occupied by toolbars. To the left of the working area are the "floating toolbars" Draw and Modify. They can be moved anywhere on the screen. Other panels are called up as needed.

· Command line. Below the working graphics area is the command line. Any AutoCAD command can be run by typing its name on the command line. If a command is launched via a toolbar icon or a menu item, the command line also displays the system's response to the corresponding command. In addition, whatever is entered from the keyboard immediately appears on the command line. Any command is initiated only after the completion of the previous one. At the same time, the command line should contain a command prompt Command... You can undo any action by pressing a key on the keyboard. Esc.

· Status bar. The status bar displays the coordinates of the crosshair, which change as you move the crosshair with the mouse.

1. Click on File in the top line of the standard toolbar, then select from the list Save as... A dialog box will appear on the screen. Save Drawing As with a list of all folders on the selected disc.

2. In the top line of the window Save in: (Folder :) it is necessary to set the name of the created folder. To do this, from all the listed ones, select the desired folder and double-click on it.

3. In the field File Name enter a name for the drawing, for example Drawing1, and press Enter or click on the button Save.

Sign Out. You can use one of the following actions to log out of the system:

Click the button Close- a cross in the upper right corner of the screen;

Type a word on the command line Quit and press Enter;

Choose from the menu File → Exit.

If the information in the drawing has not been saved, AutoCAD will offer to save it. You can accept this offer by answering Yes, you can log out without saving the latest changes by answering No, and refuse to exit and return to the drawing by pressing Cancel.

Menus and toolbars. Calling AutoCAD commands is carried out from the menu or using the toolbar icons. The system menu bar in AutoCAD consists of the following drop-down menus:

· File- the menu is intended for opening, saving, printing, exporting to other file formats (drawings), as well as exiting the system;

· Edit- menu for editing parts of the drawing in the working area;

· View- screen control menu, switching between paper space and model modes, setting the point of view for three-dimensional models, rendering, managing display parameters;

· Insert- menu of commands for inserting blocks and objects from other applications;

· Format- menu for setting drawing boundaries and units of measurement, managing text style, dimensions, working with layers, color, type and thickness of lines;

· Tools- menu of system controls, setting of drawing parameters, bindings and user coordinate system;

· Draw- menu of graphic primitives;

· Dimension- menu of commands for drawing dimensions;

· Modify- menu for editing graphic objects;

· Window- standard Windows menu for managing and sorting open drawings (files);

· Help- help menu;

· Express–Optional menu for full installation for quick access to commands.

The standard toolbar contains the following tools:

· QNew (Quick New Project)- quickly create a new file;

· Open ...- open an existing file;

· Plot ... (Print)- output the drawing to the printer;

· Plot Preview- a preview of the drawing before printing, allowing you to see the placement of the drawing on a sheet of paper;

· 3DDWF- download the interface for publishing 3D DWF projects;

· Cut- delete the selected elements of the drawing to the Microsoft Windows clipboard;

· Copy- copy the selected elements of the drawing to the Windows clipboard;

· Paste- insert data from the Microsoft Windows clipboard;

· Match Properties- assign the properties of a given object to another object;

· Block Editor– calls a menu of available blocks in the drawing;

· Undo- undo the last action;

· Redo (repetition)- restore the just canceled action;

· Pan Realtime- move the drawing relative to the point;

· Zoom Realtime- scale the drawing relative to the point;

· Zoom Window- scale the drawing within the window selected by the user's mouse;

· Zoom Previous– returns to the overview the previous scaling;

· Properties– opens drawing properties;

· DesignCenter– opens the built-in library of drawing elements;

· Tool Palettes Window– enables / disables the display of the palette window in the workspace;

· Sheet Set Manager– opens the schema manager;

· Markup Set Manager– opens the layout manager of drawings;

· QuickCalc (Quick Calculator)- calls up the calculator;

· Help- opens the help;

· Layer Properties Manager- opens the layer properties manager. A little to the right are the main commands for layers - turn on / off a layer, lock / move a layer from all points, lock / move a layer from a specific point and choose a color for the layer.

To work with the AutoCAD editor, commands are used that can be entered in various ways: by typing on the keyboard, selecting from the menu, or clicking the corresponding icon on the toolbar. The command can be entered only at the moment when the prompt is displayed in the command line window Command:... To enter a command from the keyboard, type the command name and press Enter... It is allowed to enter the abbreviation of the commands for which it is defined. So, for the team Circle can enter WITH... Commands can be entered using toolbars. Toolbars can be either floating or docked, with a fixed location. Floating panels can move around the graphics area and resize, docked panels cannot resize and overlap the graphics area. A floating panel can become docked if you move it outside the graphics area. A docked panel becomes floating as soon as it moves into the area of ​​the graphics field. A tool button may have a small triangle in the lower right corner. If you press the left mouse button while specifying such a tool and do not release it for a while, a toolbar will appear, containing various options for executing the selected command. After entering the command, AutoCAD issues prompts in response to which you need to enter additional information: a numerical value (for example, distance, angle, etc.), a keyword or a point; or brings up a dialog box. Some commands allow work both through the command line and through a dialog box.

The system reacts to one or another item of the called menu as follows:

· Displays a submenu if there is a black triangle on the right;

· Opens a dialog box if the item ends with an ellipsis;

· Executes the command in other cases.

Working with coordinates. When AutoCAD asks for a point, it waits for the coordinates of any point in the current drawing to be entered. After specifying a point, a small marker may appear in its place for better orientation, which disappears after regeneration or redrawing.

Coordinates can be entered in AutoCAD in two ways: directly from the keyboard by specifying numerical values ​​and using a graphic marker (cursor), which moves across the screen with a pointing device. Coordinates are entered by pressing the left mouse button. The current coordinates are displayed in the status bar.

Numerical values ​​can be: whole, real given in decimal format, exponential, and as fractions... The numerator and denominator of the fraction must be whole, and the denominator must be greater than the numerator. Numerical values ​​in AutoCAD define conventional units. The conventional unit can correspond to any length unit: meters, inches, feet, centimeters, angstroms, etc. So, when drawing, you can operate with real dimensions without thinking about scaling. The finished drawing can be drawn at any given scale.

In two-dimensional space, a point is defined in the plane XY, which is called plane of construction... Coordinates can be entered from the keyboard in the form of absolute and relative coordinates. Absolute coordinates can be entered in the following formats: rectangular coordinates X, Y and polar coordinates r< А , where r- radius and BUT- angle from the previous point. The angle is given in degrees counterclockwise. Relative coordinates specify the offset from the last point entered. When entering points in relative coordinates, you can use any format of notation in absolute coordinates: @dx, dy- for rectangular, @r< А - for polar ones.

Coordinate values, regardless of the input method, are always associated with some coordinate system... By default, AutoCAD uses the so-called world coordinate system (WCS) (WCS)... It is defined so that the axis OH directed from left to right, axis OY- from bottom to top, axis OZ- perpendicular to the screen outward.

For the convenience of work, it can be determined user coordinate system (UCS) (UCS), which can be offset relative to the world and rotated at any angle.

AutoCAD has the ability to set the modes of drawing lines. This is polar mode in which the lines are drawn at different angles, and orthogonal, in which lines are drawn only along the coordinate axes. Switching modes is carried out by pressing the key on the keyboard F8 or by clicking the command button Ortho Mode on the status bar.

To accurately enter the coordinates of points using the mouse, AutoCAD has special commands:

Step-by-step SNAP- the mode of movement of the mouse pointer with a certain step, which is not necessarily equal to the step of the imaginary grid (the grid can be made visible using the command Grid);

Object snapping OSNAP- mode of binding coordinates to various points of already created objects.

You can enable and disable these modes using the corresponding command buttons on the status bar. You can adjust the binding characteristics in the dialog box Tools → Drafting Settings ... by setting the appropriate bookmark, or select the corresponding command buttons in the status bar, right-click and select the option Settings ...:

· Snap and Grid- to set the snap and grid parameters (Fig. 2.2):

Rice. 2.2. Drafting Settings Dialog Box, Snap and Grid Tab

· Object Snap- to set the object snapping parameters (Fig. 2.3);

Rice. 2.3. Drafting Settings Dialog Box, Object Snap Tab

Geometric elements of the drawing. Any drawing consists of sections of geometric elements (graphic primitives), for example, straight and curved lines. To draw straight sections of the drawing, use the tools Line, Construction Line, Multiline, Polyline, Polygon and Rectangle... Curved sections are created with tools Arc, Circle, Spline, Ellipse, Hatch ... and others.

The specified tools correspond to certain commands for drawing the corresponding primitives. The description of these commands is given below in the sequence of the arrangement of the icons (from left to right) on the toolbar. Draw(fig. 2.4).

Rice. 2.4. Draw toolbar

_Line command. Team _line belongs to a group of commands that are repeated an arbitrary number of times until a key is pressed Enter... It has two options that can be selected from the context menu of the command while drawing line segments or by capitalizing a letter from the keyboard:

· Undo (Return)- erases the last formed segment of the polyline without completing the command;

· Close- automatically draws the last segment, closing the line (the option appears only after the second drawn segment).

_Xline command. Team _xline serves to draw auxiliary lines, which can be used, for example, as communication lines between projections of a part. The difference between this primitive and a simple line is that it is automatically extended in both directions to the borders of the screen, regardless of the image scale.

Team _xline has five options:

· Hor– to draw horizontal lines ;

· Ver– to draw vertical lines ;

· Ang– to draw oblique lines at a certain angle, the value of which is entered from the keyboard at the corresponding command prompt ;

· Bisect– to construct the bisector of an angle by its vertex and two points located on the sides of the angle ;

· Offset– to build a straight line parallel to any specified segment at a specified distance or through a specified point .

Team _xline Since AutoCAD 2000, it has lost its relevance, as in new versions there was a tracking function for object snaps (button Otrack in the status bar), which allows you to generate temporary construction lines, instead of real geometric constructions.

_Mline command. Team _mline builds a set of parallel (no more than 16) polylines, which are called elements. The command has three options:

1. Justification (Location)– defines the position of the plotting point :

· Thor (Top)- the line passes with the maximum positive offset from the specified point;

· Zero (Center)- the line runs with zero offset from the specified point;

· Bottom- the line passes with the maximum negative offset from the specified point;

2. Scale– the number by which the offset between the lines is multiplied, set in the multiline style ;

3. Style– style selection (style name is entered from the keyboard), style is loaded by default Standard, which allows you to draw a line consisting of two parallel straight lines .

To select options, you can use the context menu or type capital letters of option names at the command line.

When specifying options from the keyboard, you must type the capital letters of the Latin alphabet, marked on the command line. For example, to select the option Style you must enter two letters from the keyboard - ST.

_Pline command. Team _ pline allows you to build a sequence of straight and arc segments. On straight sections, the command allows you to change the width both when moving from one segment to another, and within one segment. The command has six options:

· Halfwidth– allows you to set the half-width (distance from the centerline of the segment to the edge) ;

· Width– allows you to set the width of the subsequent segment (AutoCAD asks for the start and end width) ;

· Undo– cancels the last created segment ;

· Arc– puts the command in the mode of drawing arcs ;

· Close– closes the line with a line segment ;

· Length– defines the next straight line segment in the same direction as the previous one .

_Polygon command. Team _polygon builds a regular polygon with the number of sides from 3 to 1024. After calling the command, in response to the system request, enter the number of sides of the polygon. Then you need to choose one of three methods for defining the polygon, which correspond to the command options:

· Edge – defines the position of any edge of a polygon by two given points ;

· Inscribed in circle– forms an imaginary circle at the given center and radius, into which the polygon will be inscribed ;

· Circumscribed– forms an imaginary circle at the given center and radius around which the polygon will be described.

The last two options appear after specifying the center of the circle.

_Rectang command. Team _rectang allows you to build a rectangle from two opposite vertices. To define the vertices, you can use any method of entering coordinates. The rectangle can be chamfered and rounded using the following options:

· Area- forms bevels at the corners when specifying the distance from the top to the bevel along both sides;

· Dimensions- forms rounding of corners when entering a value for the radius of fillet;

· Rotation- sets the angle of rotation of the figure;

In addition to the listed options, the command contains three more options with which you can form a box with a rectangle at the base. However, most often this command is used to define a rectangle in a plane. XY.

_Arc command (arc). Team _arc allows you to draw a part of a circle. There are different ways to define an arc in AutoCAD. In fig. 2.5 shows the command options that allow you to draw an arc in one way or another. Options are selected via submenu Arc menu Draw... Depending on the selected option, the arc can be drawn either in the first seven ways (drawing is done from the point of the beginning of the arc) or in the penultimate three (the beginning of the drawing is the center of the arc). If you call the command using the icon, the system will prompt you to enter the starting point of the arc or its center. When choosing an option Continue you can draw an arc, the starting point of which will be the end point of the previous arc or line. Moreover, the arc will go tangentially to the previous element.

Rice. 2.5. _Arc command options

It should be noted that arcs are drawn from the starting point counterclockwise, however, you can enter the value of the central angle and the length of the chord with a minus sign.

_Circle command. Team _circle allows you to draw a circle in one of six ways:

· on two points of diameter circles - options 2 Points (2 points);

· on three points of the circle- options 3 Points;

· on two tangents (two line segments, a segment and a circle, etc.) and a radius- options TanTan Radius;

· on three tangents- options Tan Tan Radius.

Command options are selected from a submenu Circle menu Draw or in the process of a dialogue from the context menu of the command (Fig. 2.6).

Rice. 2.6. _Circle command options

_Spline command. Team _spline allows you to draw a wavy line in the drawing. Spline is built by points that are sequentially entered after calling the command. In order to complete the construction of the spline, you need to press the right mouse button, select from the context menu Enter- press the left button, then press the right mouse button 2 times.

_Ellipse command (Ellipse). Team _ellipse allows you to draw both a complete ellipse and a part of it. The main parameters of the ellipse are the coordinates of the center, the direction and size of the major and minor axes.

A complete ellipse can be drawn in two ways:

Define the center of the ellipse, and then the rest of the parameters - select an option Center

Define the end points of the ellipse axes - select an option Axis, End.

An option is available to rotate the ellipse using the command Rotation... To build a part of the ellipse, select the option Ellipse Arc.

_Bhatch command. At shading the areas bounded by a closed contour consisting of line segments, circular arcs, etc. are filled. For shading, 2 properties are characteristic:

Shading is block;

Shading happens associated with an object (associative), i.e. when the object changes, it automatically adjusts to its shape, and unrelated (non-associative).

To create a hatch, you need to click on the icon Hatch ... toolbars Draw or call a command from the drop-down menu with the same name.

After running the command, the hatch dialog appears on the screen (fig. 2.7), in which you can:

Select the desired shading - window Tour (Type) install "User defined";

Define the part of the drawing that you want to shade - buttons Pick Points and ;

Set hatch parameters - list boxes Angle and Scale;

Preview the hatching before its output - the button Preview.

Rice. 2.7. Hatch Dialog Box

Define the area for hatching can be done in two ways: specify a point within the area (click with the mouse) or select objects that bound the area. In the first case, you need to press the button Pick Points, and in the second - the button Select objects.

To create several contours, after specifying the button Pick Points select several interior points belonging to different areas. Bookmark Gradient opens a window, the options of which allow you to specify additional methods for selecting the hatch contour and set gradients.

Shading is removed in the same way as any other primitive. To select it, just click with the mouse on the screen anywhere in the shaded area. A hatch already in the drawing can be edited. To edit the hatching, select from the drop-down menu Properties option Hatch... After selecting a hatch, a dialog box appears on the screen Hatch and Gradient, in which the new required parameters are set.

Tasks. Using the appropriate commands with specific queries (parameters), perform the following exercises:

1. Through the dialog box Options ... which is called through the menu Tools, set the desired screen parameters (the Display). Using commands Color and Linetype choose the color and type of the line.

2. Construct a polyline consisting of 5 segments. The coordinates of the nodal points: 95, 44; 185, 194; 260, 164; 228, 160; 298, 104; 95, 44.

3. Construct a polygon consisting of 7 segments with arbitrary coordinates of points, using various numerical values ​​(integers, real, in exponential form, given in decimal format and in the form of fractions).

4. Using relative coordinates, construct an isosceles trapezoid with base 160 and height 180.

5. Using relative coordinates, construct an isosceles right-angled triangle with leg 225.

6. Construct an ellipse: by two points on the main axis 30, 10; 150, 30 and the length of the second axle 25.

7. Construct the ring: inner diameter 150, outer diameter 180, center 200, 225.

8. Construct polygons: a pentagon inscribed in a circle with a radius of 40, and a hexagon circumscribed around a circle with a radius of 87.

9. Construct a spline curve by five points; the points and directions of the tangents can be chosen arbitrarily.

10. Construct a closed strip with a width of 2 by five arbitrary points.