1. PowerPoint Presentation
Publisher The Goodheart-Willcox Co., Inc. Tinley Park, Illinois 1

2. Drawing Instruments and Techniques
Chapter 4
Drawing Instruments and Techniques 2

3. Chapter 4 Overview Introduction Orthographic Projection
Three Principal Views
Architectural Manual Drafting Equipment
Freehand Sketching 3
(continued)

4. Chapter 4 Overview Computer-Aided Drafting and Design
Lines Used in Architectural Drafting
Architectural Lettering
CADD Symbols Library 4

5. Learning Objectives
Define the three principal views in orthographic projection.
List and explain the use of architectural drafting equipment.
Explain the difference between size and scale.
Reproduce the standard alphabet of lines.
(continued) 5

6. Learning Objectives
Demonstrate an acceptable architectural lettering style.
Freehand sketch.
Identify the basic components of a CADD workstation. 6

7. Introduction
Understanding basic drafting practices and the use of equipment is expected before attempting architectural drafting.
Most of the equipment and principles are similar to mechanical drafting.
A review of the basic drawing concepts will establish a foundation for architectural drafting. 7

8. Orthographic Projection
Orthographic projection is the most basic drafting technique.
A means of representing the height, width, and depth of a three-dimensional object on two-dimensional paper.
The object is viewed at infinity, thus projection lines are parallel to each other.
Typically, three views are used. 8

9. Orthographic Projection
This camp cottage shows the arrangement of views in orthographic projection. 9

10. Three Principal Views
The three principal views in orthographic projection are the top, front, and right side views.
In architectural drafting, the views are similar but have different names.
The top view of a house is called a plan view; used as the basis for most other drawings.
(continued) 10

11. Three Principal Views
The floor plan is a top view in section taken about half way up the wall.
The front elevation in architectural drafting is the same as the front view in mechanical drafting.
Architectural drafters ordinarily draw a view of each side of the structure, which are called elevations. 11

12. Three Principal Views
How orthographic views are projected. 12

13. Drafting Equipment
An architectural drafter uses equipment that is designed for specific purposes.
Using this specialized equipment requires skill and understanding.
The manual drafter uses traditional equipment such as triangles and scales.
The CADD drafter produces drawings on a computer.
(continued) 13

14. Drafting Equipment Common manual drafting equipment. (continued) 14
(Koh-I-Noor Rapidograph, Inc.)

15. Drafting Equipment
Common CADD workstation. 15

16. Traditional Drafting Equipment
Pencils used in manual drafting are available in wood and mechanical types.
(continued) 16
(Berol USA)

17. Traditional Drafting Equipment
The most popular types of erasers used by architectural drafters are rubber and plastic.
(continued) 17

18. Traditional Drafting Equipment
Electric erasers can be used to quickly erase large areas.
(continued) 18
(Staedtler Mars GmbH & Co.)

19. Traditional Drafting Equipment
Erasing shields are made of metal or plastic. They are thin to provide for accurate erasing.
(continued) 19
(Staedtler Mars GmbH & Co.)

20. Traditional Drafting Equipment
Most architectural drawings are finished on tracing paper, velum, or drafting film.
Paper Sizes
A-size (9" x 12")
B-size (12" x 18")
C-size (18" x 24")
D-size (24" x 36")
E-size (36" x 48")
(continued) 20

21. Traditional Drafting Equipment
Common paper sizes.
(continued) 21

22. Traditional Drafting Equipment
Drawing Boards
Standard sizes:12" x 18", 18" x 24", 24" x 36", and 30" x 42".
Materials: White pine, basswood, and plywood.
T-Squares
Materials: Wood, metal, plastics, and a combination.
(continued) 22

23. Traditional Drafting Equipment
Drafting machines speed the work of the manual drafter and are usually permanently attached to the drafting table.
(continued) 23
(Vemco Corporation)

24. Traditional Drafting Equipment
Triangles are used to draw nonhorizontal lines.
45° and 30°-60° triangles.
Metal or plastic.
Adjustable triangle (shown).
(continued) 24
(Staedtler Mars GmbH & Co.)

25. Traditional Drafting Equipment
Protractors are used for measuring angles.
Semicircular and circular styles.
(continued) 25

26. Traditional Drafting Equipment
Architectural drafters use architect’s, engineer’s, and combination scales. 26

27. Architect’s Scale
Divided into 3/32", 3/16", 1/8", 1/4", 1/2", 3/8", 3/4", 1", 1-1/2", and 3" to the foot.
One edge divided into 16 parts to the inch.
Divisions based on 12 units to the foot.
Used for most work. 27

28. Engineer’s Scale
Divided into 10, 20, 30, 40, 50, and 60 parts to the inch.
Divisions based on 10 units to the inch.
The engineer’s scale is used by the architectural drafter to draw plot plans. 28

29. Combination Scale
Divided into 1/8", 1/4", 1/2", 3/8", 3/4", and 1" to the foot.
One edge is divided into 50 parts to the inch.
One edge is divided into 16 parts to the inch.
Divisions include 12 units to the foot and 10 units to the inch. 29

30. Size Compared to Scale “Size” and “scale” need clarification.
“Half size” means the drawing is one half as large as the object.
Scale: 1/2" = 1'-0" means the drawing is 1/2 scale.
1/2 scale means 1/2" on the drawing = 1'-0" on the object.
Residential plans are generally 1/4" = 1'-0" scale. 30

31. Reading the Scale
The 1/8" = 1'-0" and 1/4"=1'-0" scales are printed on the upper edge of this architect’s scale.
(continued) 31

32. Reading the Scale
The proper method of measuring 16'-4" using the 1/4" = 1'-0" scale. 32

33. Traditional Drafting Equipment
Dividers are used to divide a line into a number of parts.
Three types are shown.
(continued) 33

34. Traditional Drafting Equipment
The compass is used to draw circles, arcs, or radii.
Center-wheel type shown.
(continued) 34

35. Traditional Drafting Equipment
The beam compass is used to draw large arcs.
(continued) 35

36. Traditional Drafting Equipment
Lettering guides are used to draw guidelines for hand lettering.
Types: Ames and Braddock-Rowe.
(continued) 36

37. Traditional Drafting Equipment
Irregular curves are used to draw curved lines that cannot be drawn with a compass.
Flexible curve.
(continued) 37

38. Traditional Drafting Equipment
The case instruments may include dividers, compass, lining pens, pencil pointers, spare parts, small screwdriver, and various other instruments.
(continued) 38

39. Traditional Drafting Equipment
Lettering devices are used when uniformity of letters is essential.
Stencil type.
(continued) 39

40. Traditional Drafting Equipment
Technical pens are used to ink a drawing. Points are interchangeable and range from 000 to 8.
(continued) 40
(Staedtler Mars GmbH & Co.)

41. Traditional Drafting Equipment
Templates serve as guides in drawing special lines or symbols. Most are made of plastic.
(continued) 41
(Berol USA)

42. Traditional Drafting Equipment
Grids are available in a wide variety of sizes and forms: square, isometric, and perspective. 42

43. Freehand Sketching
Freehand sketching is a method of making a drawing without the use of instruments.
Most designers use sketches to “think through” an idea before making the final drawing.
Freehand sketching requires only a pencil and plain or grid paper.
(continued) 43

44. Freehand Sketching
Cross-section paper may be used for freehand sketching. 44

45. Sketching Technique
When sketching, hold the pencil with a grip firm enough to control the strokes.
Your arm and hand should have a free and easy movement.
As you sketch, rotate the pencil slightly between the strokes to retain the point longer.
Initial lines should be sharp and light.
(continued) 45

46. Sketching Technique
Apply light pressure to avoid making grooves in the paper.
Keep your eye on the point where the line will end; use a series of short strokes to reach that point.
When all the lines are sketched, go back and darken the lines.
Strive for neatness and good technique.
(continued) 46

47. Sketching Technique
When sketching, grip your the pencil farther back than you normally would. 47

48. Sketching Horizontal Lines
There are four basic steps. 48

49. Sketching Vertical Lines
There are four basic steps. 49

50. Sketching Inclined Lines
Locate the end points of the line.
Position arm for trial movement.
Sketch several short, light lines.
Focus on end point.
Darken the line. 50

51. Sketching an Angle First, sketch a right angle (90°).
Subdivide the right angle to get the angle you desire. 51

52. Sketching Circles and Arcs
There are several methods of sketching circles and arcs:
Centerline method.
Enclosing square method.
Hand-pivot method.
Free-circle method.
All are sufficiently accurate, so use the best method for a particular situation. 52

53. Centerline Method Locate centerlines. Mark off radius. Position arm.
Sketch the circle in short sweeps.
Darken the circle. 53

54. Enclosing Square Method
Locate centerlines.
Sketch a box equal to the diameter.
Sketch arcs where the centerlines cross the box line.
Sketch the circle. 54

55. Hand-Pivot Method
First, position the pencil and small finger. Then, rotate the paper to sketch the circle. 55

56. Sketching Ellipses
The rectangular method for sketching ellipses is similar to the enclosing square method for circles. 56

57. Sketching Irregular Curves
Sketch an irregular curve by connecting a series of points at intervals of 1/4" to 1/2" along its path. 57

58. Proportion in Sketching
Proportion is the size relationship of one part to another or to the whole object.
Keep the same width, height, and depth in proportion.
Unit method.
Pencil-sight method.
(continued) 58

59. Proportion in Sketching
Gauge proportions using the pencil-sight method. 59

60. CADD
Computer-aided drafting and design (CADD) consists of hardware and software components.
Hardware components include the physical devices.
Software programs are used to create drawings or other documents.
Output devices produce drawing hard copies. 60

61. CADD Hardware 61

62. CADD Software
The programming commands tell the computer hardware which drawing and design tasks to perform.
General and AEC CADD are available.
(continued) 62

63. CADD Software This is a CADD-generated drawing. 63
(SoftPlan Systems, Inc.)

64. CADD Output Devices Plotter Printer
Produces high-quality drawings (as shown) using pens or pencils.
Printer
Laser and inkjet printers also produce good quality. 64
(DesignJet Division, Hewlett-Packard)

65. Architectural Alphabet of Lines
Border Lines
Object Lines
Hidden Lines
Centerlines
Extension Lines
Dimension Lines
Long Break Lines
Short Break Lines
Cutting-Plane Lines
Section Lines
Guidelines
Construction Lines 65

66. Border Lines
Border lines are very heavy lines used to form a boundary for the drawing.
Use a 0.70mm pen. 66

67. Object Lines
Object lines are heavy lines that outline features of an object.
Use a 0.50mm pen. 67

68. Hidden Lines
Hidden lines represent edges that are behind a visible surface in a given view.
Use a 0.35mm pen. 68

69. Centerlines
Centerlines indicate the center of holes and symmetrical objects, such as windows and doors.
Use a 0.25mm pen. 69

70. Extension Lines
Extension lines
Extension lines are used to denote the termination points of a dimension line.
Use a 0.25mm pen. 70

71. Dimension Lines
Dimension lines are used to show size and location. They have a dimension figure halfway between the ends of the dimension line.
Use a 0.25mm pen. 71

72. Long Break Lines
Long break lines are used to show that not all of the part is shown.
Use a 0.25mm pen. 72

73. Short Break Lines
Short break lines show part of the object broken away.
Use a 0.70mm pen. 73

74. Cutting-Plane Lines
Cutting-plane lines are used to show where the object is sectioned.
Use a 0.70mm pen. 74

75. Section (Crosshatch) Lines
Section lines or crosshatch lines are used to show that a feature is sectioned.
May represent different types of material.
Use a 0.25mm pen. 75

76. Guidelines
Guidelines are used in hand lettering to keep lettering straight.
Very light lines.
Drawn in pencil only. 76

77. Construction Lines
Construction lines are used in the process of constructing a drawing.
Should not be reproduced.
Not inked or plotted. 77

78. Line Type Application
In manual drafting, all lines are black and vary only in width. Colors may be used in CADD. 78

79. Pencil Hardness Guidelines
Range from 9H (very hard) to 9B (very soft).
Use 6H for construction and guidelines.
Use 4H for dimension, extension, center, leader, long break, and section lines .
Use 2H for object, hidden, cutting plane, short break, and border lines.
Use H for lettering. 79

80. Architectural Lettering
There is no single style of architectural lettering. Most lean toward the artistic.
Develop your own style. 80

81. Developing a Lettering Style
Use guidelines for hand lettering.
Experiment with variations of letters.
Select an artistic lettering style.
Apply a basic technique to similar letters.
Make a mental picture of each letter.
Practice “your” style to gain precision.
Use your style in your work.
(continued) 81

82. Developing a Lettering Style
Variations of letters add interest.
(continued) 82

83. Developing a Lettering Style
The space between letters in a word is not constant.
Learn the spacing that looks best.
(continued) 83

84. Developing a Lettering Style
Words should not appear to run together or be too far apart.
Space between words should usually equal the height of an uppercase letter.
Most information lettered on a drawing is 1/8" or 3/32" high.
Try making the first letter in each word 1/8" and the remainder 3/32" high.
(continued) 84

85. Developing a Lettering Style
Draw the first letter of each word larger than the succeeding letters for emphasis. 85

86. CADD Symbols Library
Using a CADD symbols library provides a time savings.
Standard symbols are included in most CADD software programs.
Symbols are stored on the disk and are called up when needed.
User created symbols are possible.
Symbols may also be inserted using a digitizing tablet. 86

87. CADD Symbols Library
Symbols may be called up from the symbols library. 87