auto cad 5

lecture 5 Orthographic projection Orthographic projection involves viewing an article being described in a technical drawing from different directions ? from the front, from a side, from above, from below or from any other viewing position. Orthographic projection often involves: 1. The drawing of details which are hidden, using hidden detail lines, 2. Sectional views in which the article being drawn is imagined as being cut through and the cut surface drawn, 3. Centre lines through arcs, circles spheres and cylindrical shapes. Isometric Isometric drawings are 2-D but they appear to be in 3-D Look over example on page 132. Hatching Hatches are patterns that fill in an area. Most types of drafting make use of hatching. In architectural drafting, hatched areas are used to indicate materials, such as insulation or grass. In mechanical drafting, hatching often indicates hidden areas or certain materials. AutoCAD provide a large number of hatch patterns. Hatches are created from repeating patterns of lines. You can create solid fills in the same way that you create hatch patterns. Creating Single-Line Text It is very easy to create a single line of text using the defaults, such as font and height. Choose Home tab?Annotation panel?Single Line Text. Alternatively, choose Annotate tab?Text panel?Single Line Text. This starts the DTEXT command (which is the same as the TEXT command). Follow the prompts: Current text style: ?Standard? Text height: 0.2000 Annotative: No Specify start point of text or [Justify/Style]: Pick a start point for the text. Specify height <0.2000>: Type a height, or press Enter to accept the default. Specify rotation angle of text <0>: Type a rotation angle, or press Enter to accept the default. You see a cursor at the insertion point. Type one line of text. Press Enter. You can continue to type more lines of text. Press Enter to end the command. You can also click another location on the screen to start a new text object. Editing single-line text As with any drawing object, the need often arises to edit your text. You can edit single-line text in two ways. The most common way to edit single-line text is to use the DDEDIT command. Double-click the text to start the command. Remember that each line of text created with DTEXT or TEXT is a separate object. The text appears in a border with your text highlighted in an edit box. You can start typing to completely replace the text or click where you want to change part of the text and use standard Windows techniques to edit the text. Press Enter or click anywhere outside the border. DDEDIT prompts you to select another annotation object. Press Enter to end the command. Create and Modify MultilineText AutoCAD provide a text editor to add text to drawings. The text editor consists of a tab on the ribbon with a set of panels, and a text bounding box with a ruler at the top. These two components display automatically when you use the Multiline Text command. With the Multiline Text command, you can choose formatting that affects the entire text object or only selected text. You can also control indents and specify one or more columns. Before creating the text, you define the width of the text by specifying the two opposite corners of a text boundary. Only the width of the box has an effect. The text you enter is inserted in the dialog box within the width limit and words that don?t fit wrap to the next line. When using the text editor, you can easily change the width by dragging the right side of the ruler. NOTE The fastest way to make changes to an existing text object is to double-click it. This opens the text editor and displays the text in the bounding box. Additional features that are available for text in drawings include the following: Check spelling using a spell checker with customizable dictionaries Locate and correct text with the Find and Replace dialog box Specify several columns of text and adjust the column widths easily Create mirrored text