Arch04.ppt

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only
1
Publisher
The Goodheart-Willcox Co., Inc.
Tinley Park, Illinois

2
Chapter 4
Drawing
Instruments
and
Techniques

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

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

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)

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

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.

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.

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

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)

11
– 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.

12
• How orthographic views are projected.

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)

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

15
Drafting Equipment
• Common CADD workstation.

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

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

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

19
• Erasing shields are made of metal or plastic.
They are thin to provide for accurate erasing.
(continued)

20
• 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)

21
• Common paper sizes.
(continued)

22
• 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)

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

24
• Triangles are used
to draw
nonhorizontal lines.
– 45° and 30°-60°
triangles.
– Metal or plastic.
– Adjustable triangle
(shown).
(continued)

25
• Protractors are
used for
measuring
angles.
– Semicircular and
circular styles.
(continued)

26
• Architectural drafters use architect’s,
engineer’s, and combination scales.

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.

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.

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.

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.

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)

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

33
• Dividers are used
to divide a line into
a number of parts.
– Three types are
shown.
(continued)

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

35
• The beam compass is used to draw
large arcs.
(continued)

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

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

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

39
• Lettering devices
are used when
uniformity of letters
is essential.
– Stencil type.
(continued)

40
• Technical pens are used to ink a
drawing. Points are interchangeable
and range from 000 to 8.
(continued)

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

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

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)

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

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)

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)

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

48
Sketching Horizontal Lines
• There are four basic steps.

49
Sketching Vertical Lines
• There are four
basic steps.

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.

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

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.

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

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.

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

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

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.

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)

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

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.

61
CADD Hardware

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

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

64
CADD Output Devices
• Plotter
– Produces high-quality
drawings (as shown)
using pens or pencils.
• Printer
– Laser and inkjet
printers also produce
good quality.
(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

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

67
Object Lines
• Object lines are heavy lines that outline
features of an object.

68
Hidden Lines
• Hidden lines represent edges that are
behind a visible surface in a given view.

69
Centerlines
• Centerlines indicate the center of holes
and symmetrical objects, such as
windows and doors.

70
Extension Lines
• Extension lines are used to denote the
termination points of a dimension line.
Extension lines

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.

72
Long Break Lines
• Long break lines are used to show that
not all of the part is shown.

73
Short Break Lines
• Short break lines show part of the object
broken away.

74
Cutting-Plane Lines
• Cutting-plane lines are used to show
where the object is sectioned.

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

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

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

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

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.

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

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)

82
• Variations of letters add interest.
(continued)

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

84
• 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)

85
• Draw the first letter of each word larger
than the succeeding letters for emphasis.

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.

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

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