Document 6432939
Transcription
Document 6432939
CHAPTER 6 Architectural Lines and Lettering I N T R O D U C T I O N Drafting is a universal graphic language that uses lines, symbols, dimensions, and notes to describe a structure to be built. Lines and lettering on a drawing must be of a quality that reproduces clearly. Properly drawn lines are dark, crisp, sharp, and of a uniform thickness. There should be no variation in darkness, only a variation in thickness, known as line contrast. Certain lines are drawn thick to stand out clearly from other information on the drawing. Other lines are drawn thin. Thin lines are not necessarily less important than thick lines, but they can be subordinate for identification purposes. Recommended line thicknesses are much more defined in mechanical drafting for manufacturing than in architectural drafting. Architectural drafting line standards have traditionally been more flexible, and the creativity of the individual drafter or company can influence line and lettering applications. This is not to say that drafters can do anything that they desire when preparing an architectural drawing. This chapter presents some general guidelines, styles, and techniques that are recommended for architectural drafting. Practices using CADD are covered in Chapter 7 and applied to specific content in later chapters. TYPES OF LINES Lines are the primary method of displaying images on architectural drawings. The lines must accurately and clearly represent the drawing content. There are a variety of line types found on drawings. Each type of line conveys a meaning in the way it is represented and its placement on the drawing. There are basically two widths of lines commonly found on architectural drawings, thick and thin. The purpose of different line widths is to make certain that lines stand out more than others. Thicker lines are meant to be more dominant than other lines. They may not be any more important, but they are the first lines that are intended to be seen by the viewer. For example, when you look at a floor plan, the wall lines and related features should be the main focus at first glance. Other lines, such as dimension lines, are equally important, but their appearance is subordinate to the lines used to create the plan. Even though national standards recommend two different line thicknesses for use on drawings, some companies use three line thicknesses to represent different lines on a drawing. Confirm the actual practice used by your school or company. This discussion introduces you to each of the lines commonly used in architectural drafting. Figure 6-1 shows each type of architectural line and its desired width. Construction Lines and Guidelines Construction lines are used for laying out a drawing. They are drawn very lightly so they do not reproduce and so they are not mistaken for any other lines on the drawing. Manually drawn construction lines are drawn with very little pressure using a pencil with 4H to 6H lead, and if drawn properly do not need to be erased. Use construction lines for all preliminary work. Construction lines are drawn on a separate layer when CADD is used. This layer can be turned on or off as needed. CADD layers are discussed in Chapter 7. Guidelines are similar to construction lines in that they should be drawn lightly enough so they do not reproduce. Guidelines are drawn to guide your manual lettering. For example, if lettering on a drawing is 1/8" (3 mm) high, then the lightly drawn guidelines are placed 1/8" (3 mm) apart. Guidelines are not used with CADD. Some manual drafters prefer to use a light-blue lead rather than a graphite lead for all construction lines and guidelines. Light-blue lead does not reproduce in a diazo printer and is usually cleaner than graphite. Blueline can reproduce in a photocopy machine unless it is drawn very lightly. Object Lines In architectural drafting the outline lines—or object lines, as they are commonly called—are a specific thickness so they stand out from other lines, as they form the outline of views. Object lines are used to define the outline and characteristic features of architectural plan components, but the method of presentation can differ 87 88 Architectural Drafting and Design THICK VISIBLE OBJECT LINES THICK LINE APPROXIMATE WIDTH: 0.025" (0.6 mm) FLOOR PLAN WALL OUTLINES, ELEVATION OUTLINE/ACCENT, SECTION ACCENT, FOUNDATION OUTLINES AND BEAMS THIN THIN LINE THIN LINE APPROXIMATE WIDTH: 0.012" (0.3 mm) FLOOR PLAN SYMBOLS, ELEVATION FEATURES, SECTION FEATURES THIN HIDDEN LINE THIN LINE APPROXIMATE WIDTH: 0.012" (0.3 mm) THIN CENTER LINE EXTENSION LINE LEADER DOT DIMENSION LINE DIMENSION LINE, EXTENSION LINE, AND LEADER LINE THIN 20'0" SLASH ARROWHEAD THICK CUTTING-PLANE LINE OR VIEWING-PLANE LINE THICK THICK THICK SHORT BREAKS BREAK LINE THIN LONG BREAKS THICK CHAIN LINE THICK LINE APPROXIMATE WIDTH: 0.025" (0.6 mm) PROPERTY LINES DIMENSION LINE VISIBLE OBJECT LINE GARB. DISP. GFI GFI DW HIDDEN LINE HOOD W/ LIGHT & FAN. VENT TO OUTSIDE AIR 12'-0" LEADER LINE REFR 48"X72" LIGHT SOFFIT W/ 5-48" PERIOD FIXTURES S3 DBL OVEN HIDDEN LINE BREAK LINE BRM S S 3 EXTENSION LINE CUTTING-PLANE LINE THIN LINE FIGURE 61 Recommended architectural line styles and weights, with an example as used in a partial floor plan. Chapter 6: Architectural Lines and Lettering 89 slightly from one office to another. The following techniques are alternatives for object line presentation: ● A popular technique is to enhance certain drawing features so they stand out clearly from outer items on the drawing. For example, the outline of floor plan walls and partitions, or beams in a cross section, can be drawn thicker than other lines so that they are more apparent than the other lines on the drawing. When drawn manually, these thicker lines can be drawn with a mechanical pencil or 0.7-mm or 0.9-mm automatic pencil using a 2H, H, or F lead (see Figure 6-2A). This technique can also use light shading to highlight the walls of a floor plan. Dark shading can be used, but it hides the thicker outline lines. ● Another technique is for all lines of the drawing to be the same thickness. This method does not differentiate one type of line from another, except that construction lines are always very lightly drawn. The idea of this technique is to make all lines medium-thick to save drafting time. The drafter uses a lead that works best, although a mechanical pencil or 0.5-mm automatic pencil with 2H or H lead is popular (see Figure 6-2B). This technique can use dark shading to highlight features such as walls in floor plans, as shown in Figure 6-2C. The objective with any manual drafting line work is to get all lines dark and crisp. If the lines are fuzzy, they do not reproduce well. ● Some object lines may not be drawn as thick as others. This idea can be confusing at first. When you are creating an architectural drawing, you need to think about what features you want to be most visual. On a floor plan, for example, the outlines of the walls might be drawn thick to stand out clearly from other features. However, the outlines of cabinets, doors, and other objects might be drawn thin even though they are objects and their outlines might be considered object lines. The partial floor plan in Figure 6-1 shows this variation between object lines. Although this practice is common, the confusion can be compounded for the beginner because some variations can exist between offices. The best thing for you to do is spend as much time as you can looking at sets of architectural drawings with the goal of observing how lines are displayed. Also, quickly become familiar with the methods preferred by your instructor and the company where you work. 10'–0" 10'–0" 5'–0" 5'–0" 5'–0" 5'–0" ALL LINES SAME THICKNESS THICK WALL OUTLINES B 10'–0" 5'–0" 5'–0" THICK LINES FOR BEAMS AND FOOTINGS DARK SHADING A THICK LINES FOR FOUNDATION WALL C FIGURE 62 (A) Thick outlines. (B) All lines the same thickness. (C) Accent with shading. 90 Architectural Drafting and Design Dashed Lines In mechanical drafting dashed lines are called hidden lines; the terms are interchangeable in architectural drafting. Dashed lines are used to show drawing features that are not visible in the view or plan. In architectural drafting, dashed lines can also be considered hidden lines because they are used to show drawing features that are not visible in the view or plan. These dashed features are important but subordinate to the main emphasis of the drawing. Dashed lines vary slightly from one office to the next. These lines are thin and generally drawn about 1/8" to 3/8" (3 to 10 mm) in length with a space of 1/16" to 1/8" (1.5 to 3 mm) between dashes. The dashes should be kept uniform in length on the drawing, for example, all 1/4" (6 mm) should have equal spaces. Dashed lines are thin, and the spacing between dashes should not be measured, but should be approximately the same. Draw dashed lines manually by estimating the dash length and spacing. It takes practice to manually draw dashed lines. Recommended leads for manual drafting are a 0.5-mm automatic pencil with 2H or H lead, or a sharp mechanical pencil with 4H, 2H, or H lead. Examples of dashed-line representations include beams shown in Figure 6-3, headers shown in Figure 6-4, and upper kitchen cabinets, dishwasher, and electrical circuit runs as shown in Figure 6-5. These concepts are discussed again throughout this textbook as used with specific applications. Extension and Dimension Lines Extension lines show the extent of a dimension. Dimension lines show the length of the dimension and terminate at the related extension lines with slashes, 4 X 12 BEAM DASHED LINE BEAM FIGURE 63 Dashed line beam representation. 4 X 14 HDR. DASHED LINE HEADER FIGURE 64 Dashed line header representation. DASHED LINE DISHWASHER DASHED LINE UPPER CABINETS DASHED LINE ELECTRICAL CIRCUIT RUN FIGURE 65 Dashed lines for upper kitchen cabinets, dishwasher, and electrical circuit runs. arrowheads, or dots. The dimension numeral in feet and inches, or millimeters, is generally placed above and near the center of the dimension line. Extension lines generally start a short distance, such as 1/16" (1.5 mm) away from the feature being dimensioned and typically run 1/8" (3 mm) beyond the last dimension line. When you are dimensioning to a feature such as the center of a window, the center line becomes an extension line. Figure 6-6 shows several extension and dimension lines. Further discussion and examples are provided in later chapters. Extension and dimension lines are generally thin, dark, crisp lines that can be drawn with a sharp mechanical pencil or 0.5-mm automatic pencil using 4H, 2H, or H lead, depending on the amount of pressure you use. Leader Lines Leader lines are also thin, dark, crisp lines. These lines are used to connect notes to related features Chapter 6: Architectural Lines and Lettering 91 DIMENSION LINE 10'-0" EXTENSION LINE 5'-0" 5'-0" 1/8 45° CENTER-LINE EXTENSION LINE FREEHAND SLASH ALL IN THE SAME DIRECTION 10'-0" 5'-0" 1/8" A THICK SLASH IS COMMON ON MANY MANUAL AND CADD DRAWINGS SOME COMPANIES USE A DOT TO END DIMENSION LINES TO 3/16" 5'-0" 1/16 FREEHAND ARROWHEAD CADD ARROWHEADS MAY BE FILLED OR UNFILLED FIGURE 66 Extension and dimension lines. on a drawing. Leader lines can be drawn freehand or with an irregular curve. Do them freehand if you can do a good job, but use an irregular curve if they are not smooth. Confirm the preferred practice with your school or company standards. The leader should start from the vertical center at the beginning or end of a note and be terminated with an arrowhead at the feature. Some companies prefer that leaders be straight lines beginning with a short shoulder and angling to the feature. Figure 6-7 shows several examples. 2 X 6 PT SILL 1/2"o X 10" A.B. @ 6'–0" O.C. 8" X 16" CONC. FTG. 8" THICK FND. WALL ALL FIGURE 67 Sample leader lines. The style for leaders should be the same throughout the drawing. Break Lines Break lines are used, for example, to remove a portion of an object, to show a partial view, or to shorten a long object. Break lines are also used to terminate features on a drawing when the extent of the feature has been clearly defined. Two types of break lines can be used in architectural drafting: the long break line and the short break line. The long break line is normally associated with architectural drafting, and uses a break symbol that is generally drawn freehand. Figure 6-8A shows several examples. The short break line can be found on some architectural drawings. This line, as shown in Figure 6-8A, is an irregular line drawn freehand and is used for a short area. The short break line is less commonly used in architectural drafting than the long break line. Breaks in cylindrical objects such as steel bars and pipes are shown in Figure 6-8B. LINE TECHNIQUES For more information and instructions covering manual drafting techniques for drawing lines with pencil on vellum, polyester lead on polyester film, and inking on vellum and polyester film, refer to the Student CD: LINE TECHNIQUES. 92 Architectural Drafting and Design LONG BREAK LINE 1/3 R R LONG BREAK LINE ALTERNATE SYMMETRICAL ABOUT CENTER 1/2 R SHORT BREAK LINE NOT AS COMMON A R B FIGURE 68 (A) Solid break lines. (B) Cylindrical break lines. CADD APPLICATIONS Drawing Lines INTRODUCTION POINT ENTRY METHODS The process of specifying points to create and edit objects, such as locating line endpoints, is known as SINK 2'–0" W WASHER DRYER R 8'–0" 6" BACKK SPLASH ADJ. SHELVES L 3'–0" Drawing line segments is one of the simplest forms of CADD. To draw a line, first access the proper line tool or command. Typically, a line is drawn by specifying a start point and an endpoint. Both points are often known as endpoints. The line appears between the selected points. Usually the LINE command remains active, allowing you to create multiple connected single line segments. When finished, exit the LINE command or restart the command to draw other disconnected lines. Drawing lines using a LINE command represents the fundamental approach to creating computer-aided drawings, because a drawing is a grouping of lines and shapes. Figure 6-9, for example, shows an interior elevation drawing. If you look closely, you can see how the drawing consists of lines and different line types. As you learn more about CADD and specific CADD systems, you will become more familiar with the commands and options that allow you to create and modify complex objects without using individual line segments. 5'–3" 4 1'–10" UTILITY ELEVATION A FIGURE 69 An example of a utility room interior elevation. The drawing consists of lines assigned specific line types, created using LINE and OBJECT commands. point entry. A common traditional method of point entry relies on the Cartesian coordinate system, also referred to as rectangular coordinates. This system is based on Chapter 6: Architectural Lines and Lettering 93 CADD APPLICATIONS establishing points at a given distance from the x, y, and z axes. For two-dimensional drafting applications, objects are drawn on the x,y plane and use horizontal x and vertical y coordinates. Three-dimensional drawings make use of the z axis and require x, y, and z coordinate entry. The intersection of the axes is called the origin. This is where x = 0, y = 0, and z = 0, or the 0,0,0 coordinate is located. Absolute coordinate entry uses the exact coordinates from the origin to locate points. Figure 6-10 shows the two-dimensional Cartesian coordinate system. In this example, two lines have been drawn by entering the absolute coordinate 2,1 followed by 2,4 and finally 4,4. The z axis usually requires no consideration when preparing two-dimensional drawings. The actual entry technique varies depending on the CADD system and work environment settings. For example, typing 2,1 or #2,1 may be necessary to enter an absolute coordinate two units right and one unit up from the origin. Figure 6-10 shows how the Cartesian coordinate system is divided into quadrants. Positive and negative values specify coordinates from the origin in each quadrant. Generally, the origin is in the lower left corner of the drawing area to allow for drawing in the upper right quadrant, using positive x,y coordinates. The drawing area is often infinite in size, though drawing limits, or the specified drawing area, can be set to create a virtual drawing area according to sheet size and drawing scale. Depending on the CADD program, many point entry methods exist for placing objects, such as the endpoints of lines. Absolute coordinate entry, as well as relative, and polar coordinate entry are common. Relative coordinate entry is used when points are located at a specified – ,y –x distance on the x and y axis from the previous point. For example, when using relative coordinate entry, and the first point is located at 2,2 from the origin, the next point is 2 units directly above the first point by entering @0,2. In this example, the @ symbol indicates from the previous point. Polar coordinate entry is used when points are located from the previous point at a specified distance and angle. For example, when using polar coordinate entry, and the first point is located at 2,2 from the origin, the next point is 2 units directly above the first point by entering @2<90. In this example, the @ symbol indicates from the previous point and the < symbol establishes the polar relationship. The relative and polar coordinate entry symbols used here are for AutoCAD applications. Other CADD systems use similar or different entry methods. The most basic point entry technique is to pick points using the cursor, which can appear as a crosshair, arrow, wand, or point. Often, coordinates appear on-screen as you move the cursor to various positions. This is known as the coordinate display, and it constantly identifies where the cursor is located relative to the origin or to the previous point, as desired. Picking a point using the screen cursor can be an accurate method of point entry when specific tools or options are used to aid precise point selection. AutoCAD Snap Mode, Ortho Mode, and Polar Tracking are examples of options that help position the cursor at designated increments, and specified coordinates and angles. Other AutoCAD functions, such as Object Snaps and Object Snap Tracking, allow you to pick or reference points on existing objects. Some tools allow you to enter the length of the line and angle at which the line is drawn, significantly reducing the need to consider and identify exact coordinates. Figure 6-11 shows how a combination of drawing aids can be used to draw a 4" long line to the midpoint and perpendicular to an existing line. x,y 2,4 4,4 START P POINT AT THE MID DPOINT ENTER AN ALTERNATIVE ANGLE 2,1 ENDPOINT PERPENDICULAR TO AND 4" FROM THE MIDPOINT ORIGIN 0,0 – ,–y –x – x,–y – FIGURE 610 Using absolute coordinates and the Cartesian coordinate system to locate line endpoints. LENGTH AND DIRECTION OF CURRENT LINE ENTER THE LENGTH OF THE LINE FIGURE 611 An example of using drawing aids to precisely size and locate a line. 94 Architectural Drafting and Design CADD APPLICATIONS ASSIGNING LINE FORMAT In most situations, unique line formats are used when preparing computer-aided drawings. Many systems, such as AutoCAD layers, allow you to define the name, color, line type, line weight (thickness), and display characteristics for each line type and object. For example, a line format used to draw a door on a floor plan using visible object lines might be named Doors or A-DOOR, use a blue color, use a solid (continuous) line type, and have a thickness of .014" (0.35 mm). A line format used to draw an upper cabinet on a floor plan that uses hidden lines might be named Upper Cabinets, A-CSWK-UPPR, or A-FLOR-CSWK-UPPR, use a red color, use a dashed or hidden line type, and have a thickness of .014" (0.35 mm). Example Figure 6-12 shows a variety of single line segments drawn using CADD. The ability to use systems, such as layers, is a major advantage to CADD. The line used to represent underground natural gas lines in Figure 6-12 highlights the advantage. This complex line, complete with text and a specific line weight, would be very time consuming and less accurate if drawn manually. Different line configurations can be set before or after lines are drawn, though it is good practice to set the line format before you begin drafting. All lines drawn after you choose a specific format use that format’s characteristics. You must select a different line format each time you draw a different type of object. Still, you can modify the properties of an existing line using a variety of editing tools. ■ Purpose Name Line Type Dimensions A-ANNO-DIMS Continuous 0.3 mm Line Weight Borders and title blocks A-ANNO-TTBL Continuous 0.7 mm Doors A-DOOR Continuous 0.5 mm Underground natural gas lines A-NGAS-UNDR GAS_LINE 0.5 mm Property lines A-PROP PHANTOM 0.7 mm Upper cabinets A-FLOR-WDWK-DASH DASHED 0.5 mm FIGURE 612 Examples of common computer-aided drafting line formats. LETTERING Information on drawings that cannot be represented graphically by lines can be presented by lettered dimensions, notes, and titles. It is extremely important that these lettered items be exact, reliable, and entirely legible in order for the user to have confidence in them and never have any uncertainty as to their meaning. Poor lettering can ruin an otherwise good drawing. The following is basic terminology commonly associated with lettering: ● ● ● Composition refers to the spacing, layout, and appearance of the lettering. Justify means to align the text. Several lines of text that are left-justified are aligned along the left side, for example. Lettering is the term used to describe the traditional handmade letters and numbers on a drawing. ● Text is the term for lettering that is done using CADD. The term annotation is commonly used in architectural CADD applications to refer to any text, notes, dimensions, and text symbols on a drawing. ● A font is a complete assortment of any one size and style of lettering or text. ● Text style is a set of text characters, such as font, height, width, and angle. Lettering and text used on mechanical drafting for manufacturing follow very strict guidelines recommended by the American Society of Mechanical Engineers (ASME). Architectural lettering and text requirements follow less strict principles, but have developed as an artistic style that is commonly used by architects, architectural designers, and drafters. Chapter 6: Architectural Lines and Lettering A N B P 1 9 95 E F H I K L M T VW X Y Z & CDG J O QR S U 23456 78 3 1 – 3/4 – 0 1/2 2 4 FIGURE 613 Vertical straight element letters, curved element letters, numerals, and fractions. Single-Stroke Lettering The standard lettering that has been used for generations by drafters is called vertical single-stroke letters. The term single stroke comes from the fact that each letter is created by single straight or curved line elements that make it easy to draw and clear to read. There are uppercase and lowercase letters, although the industry has traditionally used uppercase lettering. Figure 6-13 shows the recommended strokes used to form architectural letters and numbers. Architectural lettering styles can vary, but there are similarities. Figure 6-14 shows typical architectural lettering. As a beginning drafter, you should be conservative in the style you use to create architectural letters. Too much flair causes unnatural lettering. One important point regarding lettering technique is to make letters consistent. Do not make a letter one way one time and another way the next time. Also, keep letters vertical and always use guidelines. Entry-level drafters should pay particular attention to match the style used at the architectural firm where they are employed. A professional FIGURE 614 Examples of architectural lettering. 96 FIGURE 615 Slanted letters (uppercase) and numerals. drafter should be able to letter rapidly with clarity and neatness. Slanted Lettering Most architectural drafting is done using vertical uppercase lettering and text, but some companies prefer slanted lettering. These letters slant to the right with an angle of 68° from horizontal. Structural drafting is one field where slanted lettering is commonly found. Uppercase slanted lettering is generally used for water feature names in mapping, such as streams, rivers, lakes, and oceans. Figure 6-15 shows typical slanted uppercase letters and numerals. Lettering Height Minimum lettering height should be 1/8" (3 mm). Some companies use 5/32" (4 mm). All dimension numerals, notes, and other lettered information should be the same height except for titles, drawing numbers, and other captions. Titles and subtitles, for example, can be 3/16" or 1/4" (4 or 6 mm) high. The height of numbers in fractions should be the same height as the other lettering associated with the fraction. The fraction bar can be placed horizontally at mid height of the whole numbers, or it can be placed diagonally. It is common for the fraction bar to be placed horizontally when used with dimension values and notes, but titles often use diagonal fraction bars. The exact practice depends on the preference of the architectural office. Some offices allow fraction numbers to be smaller than the other lettering, but for best readability, this is not preferred. Verify the specific requirements with your instructor or employer. Lettering Legibility Lettering should be dark, crisp, and sharp so it provides excellent reproduction quality. The composition of letters in words and the space between words in sentences should be such that the individual letters are uniformly spaced, with approximately equal background areas. Architectural Drafting and Design To achieve uniform spacing usually requires that letters such as I, N, or S be spaced slightly farther apart than L, A, or W. A minimum recommended space between letters is approximately 1/16" (1.5 mm). The space between words in a note or title should be about the same as the height of the letters. Notes should be lettered horizontally on a sheet. In some cases where space or format requires, notes can be lettered vertically so they read from the right side of the sheet. You should confirm if this is acceptable with your instructor or drafting manager. When lettering notes, sentences, or dimensions requiring more than one line, the vertical space between the lines should be a minimum of one-half the height of the letters. The maximum recommended space between lines of lettering is equal to the height of the letters. Some companies prefer to use the minimum space to conserve space, while other companies prefer the maximum space for added clarity. Some companies choose to exceed the maximum space between lines by using twice the height of letters between separate notes. Rules for Lettering and Text Numeral Applications The following outlines basic rules for placing inch and metric unit values on drawings in dimensions, notes, and specifications: ● Foot units are followed by the foot symbol ('), and inch units are followed by the inch symbol ("). ● Inches and fractions are used for values less than 12 inches, as in 6". Numerals are given in feet and inches for values equal to or over 12". A dash separates the feet and inch values, for example 8'–6". ● Metric values in architectural drafting are generally in millimeters; the abbreviation “mm” is not used when all the values are in metric. ● When metric values are used on a predominantly foot and inch drawing, the millimeter abbreviation symbol (mm) follows the metric value. ● Metric unit names are lowercase, except those resulting from proper names, for example, millimeter, meter, kilogram, Kelvin, Newton, and Pascal. ● Use vertical text for unit abbreviations. Use lowercase text, such as mm (millimeter), m (meter), and kg (kilogram), unless the unit name is derived from a proper name, as in K (Kelvin), N (Newton), or Pa (Pascal). ● Leave a space between a numeral and an abbreviation, for example, 55 kg, 24 m, 455 Hz. Chapter 6: Architectural Lines and Lettering ● ● ● ● Do not leave a space between a unit abbreviation and its prefix, for example, use kg, not k g. Do not use plural unit symbols, for example, use 5 kg, not 5 kgs. Use the plural of spelled-out metric measurements, for example, 125 meters. Use either names or symbols for units; do not mix them. Symbols are preferred on drawings. Millimeters (mm) are assumed on architectural drawings unless something else is specified. 97 HINTS FOR PROFESSIONAL LETTERING Refer to the Student CD: HINTS FOR PROFESSIONAL LETTERING, for more information on creating professional manual lettering, including making lettering guidelines, and lettering guideline templates. There is also a discussion covering the use of mechanical lettering equipment, lettering machines, and transfer lettering. CADD APPLICATION CADD Lettering The term annotation is commonly used in architectural CADD applications to refer to any text, notes, dimensions, and text symbols on a drawing. Adding annotation to a drawing is one of the most efficient and effective tasks associated with CADD. CADD eliminates the usually tedious task of freehand lettering. The process of placing text varies depending on the CADD system, the tools and commands used to generate the text, and the purpose of the text. Typically, adding text involves defining and selecting a text style, picking the text location, and typing characters using the keyboard. Some commands and options automatically add text to symbols and other drawing content. For example, dimensions used to describe the size and location of features automatically include text of dimension values when placed. Another example is a floor plan refrigerator symbol that when inserted, includes the text REFR as the abbreviation for refrigerator. TEXT STYLES Most CADD programs contain standard, or default, text styles. Default refers to any value maintained by the computer for a command or function that has variable settings. For example, the default text height might be 1/8" (3 mm), but can be changed. Though the default text style can be used to add text, a new or modified style can be more appropriate. CADD systems have multiple text options allowing you to create text styles based on the nature of the drawing and specified drafting standards. Font, height, width, and slant angle are a few of the characteristics applied to text. Figure 6-16 shows examples of CADD text styles assigned specific fonts. Most CADD programs include, or allow you to add, text fonts that resemble quality freehand architectural lettering. AutoCAD, for example, includes the CityBlueprint, CountryBlueprint, and Stylus BT fonts. These architectural fonts allow computer-aided drawings to have the artistic flair often desired in architectural drafting. The examples shown in Figure 6-16C and Figure 6-16D use an architectural text style with fonts that closely duplicate the artistry of freehand architectural lettering. Many architects and architectural drafters have adopted a less artistic style with a more computergenerated appearance. The U.S. National CAD Standard recommends using uppercase text that is proportional and nonstylized. The standard suggests a SanSerif or similar font (see Figure 6-16E). A basic uniform font such as RomanS is another alternative (see Figure 6-16F). These fonts are very clear and easy to read, and can eliminate misunderstanding, which occasionally results from the use of a more architectural appearing font. DRAWING SCALE FACTOR Depending on the CADD program, objects should be drawn full size, or full scale. This is a benefit to using CADD because you can draw according to the actual size of objects, without considering the scale factor. However, scale factor becomes an issue when adding text and other annotations. To help understand the concept of drawing scale, look at the kitchen floor plan shown in Figure 6-17. All objects, such as the walls, cabinets, and appliances are drawn full scale. This means that the sink, for example, is actually drawn 2' long. However, text that is drawn at full scale, 1/8" high for example, is extremely small compared to the other fullscale objects (see Figure 6-17A). As a result, you must adjust the text height according to the drawing scale, as shown in Figure 6-17B. Some CADD programs require you to increase the size of, or scale, text according to the drawing scale. For example, in order for text on a final drawing, plotted at a scale of 1/4" = 1'−0", to be 1/8" high, you must use a text height of 6". Six inches at this scale is actually 1/8". The scale factor establishes the relationship between 98 Architectural Drafting and Design CADD APPLICATIONS Arial font A Times font B CountryBlueprint font C Stylus BT font D SanSerif font E RomanS font F FIGURE 616 (A) Arial font. (B) Times font. Architectural text styles with fonts that closely duplicate the artistry of freehand architectural lettering can be seen in (C) CountryBlueprint and (D) StylusBT. (E ) The U.S. National CAD Standard recommends using uppercase, proportional, nonstylized text, such as the SanSerif shown here. (F ) A basic uniform font such as RomanS is another alternative. Chapter 6: Architectural Lines and Lettering 99 CADD APPLICATIONS 9'–5" 12'–7" REFR A 9'–11'5" B FIGURE 617 An example of a kitchen floor plan drawn to scale. (A) If text is drawn full scale, the text is too small compared to the large objects. (B) The text must be scaled in order to appear and be plotted correctly. the drawing scale and the desired text height. An architectural drawing to be plotted at a 1/4" = 1'−0" scale has a scale factor of 48, calculated as follows: 1/4" = 1'−0" (1/4" = 0.25") 0.25" = 12" 12/0.25 = 48 Other CADD programs automate the process of scaling text, and certain other objects, reducing the need for you to calculate the scale factor. AutoCAD Annotative Object tools, for example, allow you to select an annotation scale, which is the same as the drawing scale. Then, when you create text that uses an annotative text style, the text height adjusts according to the appropriate drawing scale text height. For example, in order for text on a final drawing, plotted at a scale of 1/4" = 1'−0", to be 1/8" high, you set an annotation scale of 1/4" = 1'−0". Then you draw the text using a text height of 1/8", ignoring the drawing scale. The 1/8" high text is scaled to 6" automatically, because of the preset 1/4" = 1'−0" annotation scale. Changing the annotation scale automatically updates the height of text according to the new scale. ADDING TEXT TO A DRAWING In some ways, the practice of adding text to an architectural drawing has not changed from manual drafting to CADD. You still must decide how the text should look, and where the text is to be located. The actual process of adding text is, however, quite different from freehand lettering. Depending on the CADD program, tools and commands are available to place a basic single line of text, paragraphs with extensive formatting, and objects that include text. Figure 6-18 shows an example of a single word created using a basic text command. To add this text to a drawing, once you access the command, you typically use point entry to specify the location for the text. Text is justified to control where the text occurs from the selected start point. Justified means to align the text. Several lines of text that are left-justified are aligned along the left side, for example. 100 Architectural Drafting and Design CADD APPLICATIONS TOP CENTER MIDDLE CENTER TOP RIGHT TOP LEFT MIDDLE RIGHT MIDDLE LEFT LEFT RIGHT BOTTOM LEFT BOTTOM CENTER CENTER BOTTOM RIGHT FIGURE 618 Some common justification options used to locate and position text. be familiar. These types of commands are especially useful in architectural drafting where an entire sheet can consist of notes and specifications. Other commands allow you to place text with objects such as the window schedule, shown in Figure 6-19B, created using a table command. Another example is the dimension shown in Figure 6-19C, created using a dimension command. In this example, lines, symbols, the dimension value, offsets, and all other dimension properties are drawn using a single dimension command. ■ 5'–5" Common justification options are shown in Figure 6-18. Justification is critical for accurately placing text. For example, use middle-center justification to place text in the center of a circle. You also have the option of rotating or further adjusting the text before it is actually created. Figure 6-19 shows examples of other text objects created using specific CADD commands. Some text commands, such as the command used to create the list of notes shown in Figure 6-19A, function much like word processing programs with which you may already A B C FIGURE 619 (A) A list of notes created using a word processing command. (B) A window schedule created using a table command. (C) A dimension placed using a specialized dimension command. ADDITIONAL RESOURCES See CD for more information The following Web sites can be used as a resource to help you find information related to drafting standards. Address www.aia.org www.ansi.org Company, Product, or Service American Institute of Architects American National Standards Institute Chapter 6: Architectural Lines and Lettering 101 Architectural Lines and Lettering Test See CD for more information QUESTIONS DIRECTIONS: Answer the following questions with short, complete statements or drawings as needed on an 8 1/2" × 11" sheet of notebook paper, or complete the electronic chapter test on the Student CD. Question 6–17 What are the minimum recommended lettering heights? 1. Letter your name, Chapter 6 Test, and the date at the top of the sheet. 2. Letter the question number and provide the answer. You do not need to write the question. Answers can be prepared on a word processor if approved by your course guidelines. Question 6–19 What is the recommended space between words in a note? Question 6–1 Is there any recommended variation in line darkness, or are all properly drawn lines the same darkness? Question 6–2 What are construction lines used for, and how should they be drawn? Question 6–3 Discuss line uniformity and line contrast. Question 6–4 Define guidelines. Question 6–5 What is the recommended thickness of outlines? Question 6–6 Identify two items that dashed lines represent on a drawing. Question 6–7 Describe a situation in which an extension line is also the center line of a feature. Question 6–8 Extension lines are thin lines that are used for what purpose? Question 6–9 Where should extension lines begin relative to the object and end relative to the last dimension line? Question 6–18 How should letters within words be spaced? Question 6–20 What is the recommended horizontal space between horizontal lines of lettering? Question 6–21 When should guidelines be used for lettering on a drawing? Question 6–22 Why are guidelines necessary for freehand lettering? Question 6–23 Describe the recommended leads and points used in mechanical and automatic pencils for freehand lettering. Question 6–24 Identify a method to help avoid smudging a drawing when lettering. Refer to the Student CD: LINE TECHNIQUES. Question 6–25 For lettering fractions, what is the recommended relationship of the fraction division line to the whole numbers on the same line? Question 6–26 List two manual methods that can be used to make guidelines rapidly. Refer to the Student CD: HINTS FOR PROFESSIONAL LETTERING. Question 6–10 Describe leaders. Question 6–27 Why should the mechanical lettering template be placed along a straightedge when lettering? Refer to the Student CD: HINTS FOR PROFESSIONAL LETTERING. Question 6–11 Describe and show an example of three methods used to terminate dimension lines at extension lines. Question 6–28 Identify an advantage of using lettering guides. Refer to the Student CD: HINTS FOR PROFESSIONAL LETTERING. Question 6–12 How does architectural line work differ from mechanical drafting line work? Question 6–29 Describe a use of lettering machines. Refer to the Student CD: HINTS FOR PROFESSIONAL LETTERING. Question 6–13 What is the advantage of drawing certain outlines thicker than other lines? Question 6–14 If all lines on a drawing are the same thickness, how can walls and partitions, for example, be represented so they stand out clearly on a floor plan? Question 6–15 Describe the proper technique to use for drawing lines with a technical pen. Refer to the Student CD: LINE TECHNIQUES. Question 6–16 Describe proper architectural lettering. Question 6–30 List four uses of transfer materials. Refer to the Student CD: HINTS FOR PROFESSIONAL LETTERING. Question 6–31 The Cartesian coordinate system is also called what? Question 6–32 What is the basis of the Cartesian coordinate system? Question 6–33 Where is the origin found in the Cartesian coordinate system? 102 Architectural Drafting and Design Question 6–34 How are points in the absolute coordinate system located relative to the origin? Question 6–35 How is an absolute coordinate specified that is 4 units on the x axis and 3 units on the y axis? 5. Question 6–36 Describe how relative coordinate points are located. Question 6–37 If the first point is located at 2,2, then how do you specify the next point, using relative coordinates, if it is to be 2 units directly above the first point? Question 6–38 Describe how polar coordinate points are located. 6. 7. 8. Question 6–39 If the first point is located at 2,2, how do you specify the next point, using polar coordinates, if it is to be 2 units directly above the first point? 9. Question 6–40 Explain how a CADD system might have commands and options that allow you to pick points accurately with the cursor. 10. Question 6–41 What is the function of the coordinate display on a CADD system? Question 6–42 Define font. Question 6–43 Define annotation. Question 6–44 What does the term default mean when applied to CADD? 11. second drawing, make all lines the same thickness. Each drawing represents a line thickness technique discussed in this chapter. Use guidelines for all lettering. Using architectural lettering, letter the title FLOOR PLAN; center it below the drawing in 1/4"-high letters. In 1/8"-high letters and centered below the title, letter the following: SCALE: 1/4" = 1'–0". Letter your name and all other notes and dimensions using 1/8" high architectural lettering. Lightly lay out the drawing using construction lines. When you are satisfied with the layout, darken all lines. For the lettering exercise, use 1/8" guidelines with 1/8" space between the lines. Leave a 3/4" minimum margin around the lettering exercise sheet. Make a diazo print or photocopy of your original drawings or lettering exercise sheet as specified by your instructor. Submit your copies and originals for evaluation and grading, unless otherwise specified by your instructor. Problems can be completed manually or with CADD, or both, depending on your specific course objectives and instructions. Confirm this with your instructor. Problem 6–1 Lines and lettering. Given the following information, draw the garage floor plan: 1. Overall dimensions are 24'−0" × 24'−0". Dimensions are measured to the outside of walls. 2. Make all walls 4" thick. Question 6–45 Explain the function of a template drawing. 3. Center a 16'−0" wide garage door in the front Question 6–46 What is another name for a template? 4. Using dashed lines, draw a 4 × 12 header over the Question 6–47 Discuss the purpose of drawing scale factors related to text height. garage door and label it 4 × 12 HEADER with a leader from the note and pointing to the header. Question 6–48 What drawing scale factor should be used if you want text 1/8" (3 mm) high on a drawing with a 1/4" = 1'−0" scale? Show your calculations. 5. Label the garage floor 4" CONC OVER 4" GRAVEL Question 6–49 Give at least three advantages of doing lettering with a CADD system. Question 6–50 Explain how it might be possible to have CADD text that looks like high-quality architectural freehand lettering. PROBLEMS DIRECTIONS: 1. Read all instructions carefully before you begin. 2. Use an 8 1/2" × 11" vellum or bond paper drawing sheet for each drawing or lettering exercise. 3. Use the architect’s scale of 1/4" = 1'–0" for each drawing. 4. Draw the floor plan described in Problem 6–1 twice. On the first drawing, use thick lines for the walls and thin lines for extension, dimension, and symbol lines. On the wall. FILL. Use a leader. Problem 6–2 Lettering practice. Using uppercase architectural lettering with proper guidelines, letter the following statement as instructed: YOUR NAME MOST ARCHITECTURAL DRAWINGS THAT ARE NOT MADE WITH CADD EQUIPMENT ARE LETTERED USING VERTICAL FREEHAND LETTERING. THE QUALITY OF THE FREEHAND LETTERING GREATLY AFFECTS THE APPEARANCE OF THE ENTIRE DRAWING. MANY ARCHITECTURAL DRAFTERS LETTER WITH PENCIL ON VELLUM OR POLYESTER LEAD ON POLYESTER FILM. LETTERING IS COMMONLY DONE WITH A SOFT, SLIGHTLY ROUNDED LEAD IN A MECHANICAL PENCIL OR A 0.5MILLIMETER LEAD IN AN AUTOMATIC PENCIL. LETTERS ARE MADE BETWEEN VERY LIGHTLY DRAWN GUIDELINES. GUIDELINES ARE PARALLEL AND SPACED AT A DISTANCE EQUAL TO THE HEIGHT OF THE LETTERS. GUIDELINES ARE REQUIRED TO HELP KEEP ALL LETTERS THE SAME UNIFORM HEIGHT. THE SPACE BETWEEN LINES OF LETTERING MAY BE BETWEEN HALF TO EQUAL THE HEIGHT OF THE LETTERS. ALWAYS USE GUIDELINES WHEN LETTERING FREEHAND. LEARN TO RELAX SO THAT THE STROKES FOR EACH Chapter 6: Architectural Lines and Lettering 103 Problem 6–3 Given the partial floor plan shown for this problem, identify the line types labeled A through K. LETTER FLOW SMOOTHLY. WHEN YOUR HAND BECOMES TIRED, REST FOR A WHILE BEFORE BEGINNING AGAIN. 54'-0" 34'-0" 15'-6" 8'-0" 7'-6" 11'-0" 11'-9" 3'-0" 3'-9" C B A REFR STA ACK PLUMBING ST D RANGE W/ MICRO OVER OVER F E G R&S 4x8 I 4x8 )2 (2 8 1'-3" X (2) 2 X 10 R&S 4 4'-2" 3' -8 " R 6X8 14 UPPER FLR OVER OVER 2'-4" 3'-4" X 6" J 6'-2" 7'-8" 10 1'-2"1'-8" 1'-10" 1'-10" 3'-6" UP CONC. FILLED HARD POST 5'-4" 3'-8" 1'-10" 9'-6" H K