Title: Dimension lines:
1Extension Line
Dimension lines Shows the beginning and the end
of the measurement. Terminated by
arrowheads. Thin line (dark) weight. Should be
broken to allow for the numbers to be
inserted. Must be a minimum of .375" or 10mm away
from the object. Must be a minimum of .250" or
6mm away from parallel dimension lines.
Dimension Line
2Extension Line
Extension lines Extend the edge of the
object. Thin line (dark) weight. There should be
a visible gap (.0625" or 1mm) between the object
and the start of the extension line. Extension
lines should extend about .125" or 2.5mm beyond
the last dimension line.
Dimension Line
3Leader lines Are drawn from a note or dimension
to place where the note applies. Are drawn at an
angle (usually 30, 45, or 60). Should have a
short (.125" or 3mm) shoulder that if extended,
would intersect the note at mid-height. May end
with an arrowhead or dot. Leaders should not
cross over or through other leaders or dimension
lines. Avoid making leaders parallel or
perpendicular to visible edges. .
4Arrowheads Can be solid filled or open. Should
be approximately .125" or 3mm long. Should be
approximately 2.5 to 3 times as long as wide.
5DIMENSIONING INCLUDES MEASUREMENTS, NOTES AND
SYMBOLS
6
61. Phantom 2. Section 3. Hidden 4.
Cutting/viewing 5. Leader 6. Hidden 7. Center 8.
Visible/object 9. Extension 10. Break 11.
Visible/object 12. Section 13. Extension 14.
Break 15. Dimension
7Procedures for using decimal and metric
measurement. Decimal inches Decimals are the
ANSI standard. Decimals are easier to add,
subtract, multiply and divide than
fractions. Preferably, decimals should be rounded
to two decimal places. Omit zero before the
decimal point for values of less than
one. Fractional inches Used where close
tolerances are not important. The horizontal
fraction bar is preferred. Metric Where linear
measurement are less than 10,000 millimeters, the
millimeter is the standard unit of measure. The
abbreviation for millimeters (mm) is usually
omitted when all dimensions are in
millimeters. The period is used as a decimal
point only in English speaking countries, others
use a comma.
8The number one rule of dimensioning is that of
clarity. Place dimensions where the shape is best
shown. Shortest dimensions placed closest to the
object. Group and align dimensions when
possible. Avoid duplicate and/or unnecessary
dimensions. Try to avoid placing dimensions
inside a view. Avoid crowding dimensions. Avoid
dimensioning to hidden features. Place dimensions
between the views to which they relate. Lines
should be thin and contrast noticeably with
visible lines. Dimensions should be included that
describe both size and location of features. The
diameter of cylinders is dimensioned in the
rectangular view. The diameter of machined holes
is dimensioned in the circular view.
9Cartesian Coordinate System
10Polar CoordinatesPolar coordinates used when you
need to draw the next points at specify angle.
Polar coordinates system in AutoCAD specifies
distance length at which angle. Using polar
coordinate, points entered by typing
_at_distanceltangle Enter
Polar Coordinate System
11Absolute Coordinate System
Relative CoordinatesAfter first points entered,
your next points can be entered by specifying the
next coordinate compare/relative from the first
points. The relative coordinate started with
symbol _at_ tell AutoCAD it was a relative
coordinates. Using relative coordinate, points
entered by typing _at_x,y Enter
12 Boolean Commands. Union ( or ?) adds parts
together Subtract or Difference ( ? ) removes
parts or features Intersection ( or ? )
Intersects overlapping volumes into a single
feature
13Purpose of a Sketch
- Quickly easily get an idea on paper
- Design sketches
- Freehand technical sketches
- Technical illustrations
14Freehand Technical Sketch
15Design Sketch
16Technical Illustration
17Sketching Lines
- Vertical lines
- Top to bottom
- Long straight lines
- Series of short straight lines
18Sketching Circles Arcs
- Begin by lightly constructing a square
19Sketching Angles
60
45
30
Subdivide once
Subdivide twice
20Sketching
- Types of Sketches
- Single-view
- Multi-view
- Pictorials
21Single-view Sketching
- Technical purposes
- Front view
- Most descriptive features
22Multi-view Sketching
- Technical sketch
- Front view
- Top view
- Side view
23Pictorial Sketches
- Quickly communicate an idea
- Three dimensions in one view
- Width
- Height
- Depth
24Pictorial Sketches
- Three (3) types
- Isometric
- Oblique
- Perspective
25Isometric Sketch
HEIGHT
WIDTH
DEPTH
26Isometric Sketching
- Three equally spaced axes of 120
27Isometric Sketching
- Receding lines
- Typically 30 off horizontal
28Isometric Sketching
- Circular shapes appear as ellipses
29Isometric Ellipses
- Correct ellipse orientation
30Isometric Sketching
- Non-Isometric lines
- Locate endpoints and connect
31Oblique Sketch
HEIGHT
DEPTH
WIDTH
32Oblique Sketching
- Front view is drawn true shape and size
33Oblique Sketching
- Receding edges are usually drawn at an angle of
30, 45, or 60
34Oblique Sketching
- Circles and curves drawn on frontal plane will
appear true shape and size
35Perspective Sketches
2-Point Perspective
1-Point Perspective
36Perspective Sketches
- Objects appear as the eye would see them
- Most realistic type of pictorial sketch
- Most difficult pictorial sketch to draw
37Drafting Equipment
38Drafting Equipment
- Drawing Horizontal lines
- T-square
- Parallel edge
- Drafting Machine
- Arm/elbow type
- Track type
39Drafting Equipment - Triangles
- 45 Triangle
- Draw vertical lines and lines _at_ 45
- 30 x 60 Triangle
- Draw vertical lines and lines _at_ 30 and 60
- Adjustable Triangle
- Draw lines _at_ 0 to 90
40Drafting Equipment - Leads
SOFT Very soft leads, smudge easily. Used for art
work of various kinds and full-size details in
architectural drawing.
MEDIUM General purpose work. Softer grades
(right) used for technical sketching, lettering,
freehand work. Harder grades (left) used for line
work on machine architectural drawings.
HARD Used where extreme accuracy is required.
Softer grades (right) used for line work on
engineering drawings. Draw very light lines.
41Drafting Equipment - Scales
- Engineer (Civil)
- Mechanical drafter
- Metric
- Architecture
42Drafting Media Types
- Vellum
- Tracing paper treated to make it more transparent
- Most commonly used drafting media
- Polyester drafting films (mylar)
- Very transparent, strong, and lasting
- Strongest drafting media
- Bond
- Standard printing and copy paper
43Drafting Media Sizes
E 44 X 34 48 X 36
D 34 X 22 36 X 24
C 22 X 17 18 X 24
B 17 X 11 12 X 18
A 11 X 8.5 9 X 12
44Lettering
- Practice of adding clear, concise words on a
drawing to help people understand the drawing - Notes lettered on rough sketches are functional
and important to operation - Simple freehand lettering completes the idea
captured in a sketch
45Lettering Composition
- Letter and word spacing should be about uniform
- Space between words should equal the approximate
width of the letter O - Background area between letters should appear
equal
46Lettering
- Practice of adding clear, concise words on a
drawing to help people understand the drawing - Notes lettered on rough sketches are functional
and important to operation - Simple freehand lettering completes the idea
captured in a sketch
47Lettering Composition
- Letter and word spacing should be about uniform
- Space between words should equal the approximate
width of the letter O - Background area between letters should appear
equal
48Guidelines
- Horizontal guidelines keep letters the same
height - Vertical guidelines aid the eye in keeping
letters from slanting - Guidelines are drawn very light and very thin
- Do not need to be erased
- Uniform vertical space should be left between
lines of letters
49Types of Lettering
- ANSI (American National Standards Institute)
- Recognizes the use of single-stroke Gothic
letters - Letters are formed using a series of strokes
- Typically all capital letters are used
- Most common lettering on Engineering Drawings
- Vertical, Uppercase, Gothic
50Lettering Standards
- Typically, most letters are .125 (3mm) tall
- Fractions are typically twice as tall as numbers
- Fraction bar is horizontal and does not touch the
numbers
51Drawing Lines
- Use parallel edge (or T-square) to draw
horizontal lines - Lean pencil at about 60
- Use triangles to draw vertical and inclined lines
52Drawing Lines at Standard Angles
53Scale Drawings
- Measurements can be full size or in some exact
proportion to full size - Triangular scales are typically used to allow for
more scales per stick - Scales are noted on drawings as
- Drawn units actual units
- Drawn units actual units
54Reading a Mechanical Scale
- FRACTIONAL INCH SCALE (FULL SIZE)
55Reading a Mechanical Scale
- FRACTIONAL INCH SCALE (HALF SIZE)
56Reading a Decimal Scale
- DECIMAL INCH SCALE (FULL SIZE)
57Reading a Decimal Scale
- DECIMAL INCH SCALE (HALF SIZE)
58Reading a Metric Scale
59Reading a Metric Scale
- HALF SCALE (2mm DIVISIONS)
60Alphabet of Lines
- Construction lines
- Thin and light
- .020 (0.5mm)
- Hard lead (4H)
- Visible lines
- Thick and dark
- .028 (0.7mm)
- Softer lead (F or HB)
61Alphabet of Lines
- Hidden lines
- Thin and dark
- .020 (0.5mm)
- Softer lead (F or HB)
- .125 (3mm) long dashes w/ .030 (1mm) spaces in
between
62Alphabet of Lines
- Center Lines
- Thin and dark
- .020 (3mm)
- Softer lead (F or HB)
- .125 (0.5mm) dash in center w/ .030 (0.1mm)
spaces between longer lines
63Alphabet of Lines
- Dimension, Extension, Leader Lines
- Thin and dark
- .020 (0.5mm)
- Softer lead (F or HB)
6.125
64Multiview Drawing
- Another name for orthographic projection is
multiview drawing - Involves visualization and implementation
- Ability to see clearly in the minds eye an
object - Process of drawing the object
65Multiview Drawing
- A system that allows you to make a
two-dimensional drawing of a three-dimensional
object
66Viewing Objects
- A box is formed by six mutually perpendicular
planes of projection that are located around the
object
67Viewing Objects
- Lines are formed on the planes by projecting the
edges of the object onto the planes
- These images are called views
- There are six views formed by the planes of a box
68Viewing Objects
- Unfolding the box produces an arrangement of the
six views
69Choosing Views
- Most commonly used views
- Front View
- Top View
- Right Side View
- Most descriptive view is typically designated as
the Front View
70Choosing Views
- Complex objects require three views to describe
its shape - Simple objects can be described with two views
- Ex Soda Can
- Thin objects can be described with only one view
- Depth is given in a note
- Ex Erasing Shield
71Object Dimensions
- All objects have 3 dimensions
- Height
- Distance from top to bottom
- Width
- Distance from side to side
- Depth
- Distance from the front to back
72Object Dimensions
- Front View
- Shows width height
- Top View
- Shows width depth
- Side View
- Shows height depth
73Drawing Views of Objects
- Depth can be projected between views by using a
45 miter line
74Line Types - Visible
- Edges that can be seen in a given view areVisible
or Object lines - Visible lines are thick and dark
- .028 or .7mm
- F or HB lead
75Line Types - Hidden
- Edges that cannot be seen from a given view are
indicated by Hidden lines
76Line Types - Hidden
- Drawing hidden lines
- .125 (3mm) dashes
- .0625 (1mm) spaces between dashes
- Thin .020 (.5mm)
- Dark F or HB lead
77Line Types Center
- Center lines indicate axes of symmetry
78Placement of Views
- Views should be visually balanced within the
working space
79Steps for Centering a Drawing
- Draw in views using light construction lines
80Straight Edges
- Edges that are perpendicular to a plane of
projection appear as a point
2
3
1
81Straight Edges
- Edges that are parallel to a plane of projection
appear as lines - Edges that are inclined to a plane of projection
appear as foreshortened lines
82Curved Edges
- Curved edges project as straight lines on the
plane to which they are perpendicular - Curved edges project as curved lines on the
planes to which they are parallel or inclined
83Inclined Surfaces
- Inclined surfaces appear as an edge in two
opposite principal views, and appear
foreshortened (not true size) in all other
principal views.
84Oblique Surfaces
- Oblique surfaces do not appear either as an edge
or true size in any principal view.
85Angles
- Acute Angle
- Measures less than 90
- Obtuse Angle
- Measures more than 90
- Right Angle
- Measures exactly 90
- Vertex
- Point at which two lines of an angle intersect
86Circle
- Radius
- Distance from the center of a circle to its edge
- Diameter
- Distance across a circle through its center
- Circumference
- Distance around the edge of a circle
- Chord
- Line across a circle that does not pass at the
circles center
87Circle
- Has 360
- Quadrant
- One fourth (quarter) of a circle
- Measures 90
- Concentric
- Two or more circles of different sizes that share
the same center point
88Triangles
- Equilateral
- All three sides are of equal length and all three
angles are equal - Isosceles
- Two sides are of equal length
- Scalene
- Sides of three different lengths and angles with
three different values
89Triangles
- Right Triangle
- One of the angles equals 90
- Hypotenuse
- The side of a right triangle that is opposite the
90 angle
90Quadrilaterals
- Square
- Four equal sides and all angles equal 90
- Rectangle
- Two sides equal lengths and all angles equal 90
- Trapezoid
- Only two sides are equal length
91Quadrilaterals
- Rhombus
- All sides are equal length and opposite angles
are equal - Rhomboid
- Opposite sides are equal length and opposite
angles are equal
92Regular Polygons
- Pentagon
- Five sided polygon
- Hexagon
- Six sided polygon
- Octagon
- Eight sided polygon
93Regular Polygons
- Distance across flats
- Measurement across the parallel sides of a
polygon - Distance across corners
- Measurement across adjacent corners of a polygon
94Solids
- Prism
- Right Rectangular
- Right Triangular
95Solids
96Geometric Terms
- Circumscribe
- Process of creating a polygon that fully encloses
a circle and is tangent to all of the polygons
sides - Inscribe
- Process of creating a polygon that is fully
enclosed by a circle at its corners
97Geometric Terms
- Bisect
- Divide into two equal parts
- Tangent
- A line and arc, or two arcs that touch each other
at one point only
98Geometric Symbols
- Angle
- Triangle
- Radius
- Diameter
- Parallel
- Perpendicular
- Square
- Centerline
R
99Terms Definitions
- Parliamentary Procedure
- A set of rules for conduct at meetings which
keeps assemblies orderly and guarantees that all
people have equal opportunity to express
themselves - Item of Business
- A single matter to be discussed or acted on by an
organization
100Terms Definitions
- Minutes
- The official written record of what was said and
done in a meeting
101Terms Definitions
- Standing
- A regular committee which usually serves for a
one year period to plan/carry out activities that
fall w/in a certain subject matter - Majority vote
- More than half the votes cast
- Two-thirds vote
- Two-thirds or more of the legal votes cast
102Terms Definitions
- Second
- An indication by a member that he or she wants to
consider the motion just proposed by another
member
103Terms Definitions
- Minority
- Less than half
- Majority
- More than half
- Quorum
- The number of members needed to be present to
legally transact business
104Motions their Purposes
- Main motion
- To present an item of business for consideration
and action by the assembly - Amend
- To change a main motion in some way add to, take
away from, or substitute words for - Postpone
- To defer action of a motion until a later time
105Steps for Processing aMain Motion
- Obtain the floor
- Be recognized by the Chair by standing and saying
Mr. Chairman - Chair assigns the floor
- The Chair recognizes one of the members by
pointing or nodding - Member makes the motion
- States I move that
- Another member seconds the motion
106Steps for Processing aMain Motion
- Chair restates the motion to the assembly
- Motions is discussed/debated by the assembly
- Vote is taken on the motion
- Vote is announced and appropriate action is taken
107Order of Business
- Opening
- Call to order, emblem ceremony, pledge to flag)
- Roll Call
- Reading of Secretarys minutes
- Treasurers report
- Committee reports
- Standing
- Ad Hoc
108Order of Business
- Unfinished business
- New business
- Program
- Speaker, film, etc
- Adjournment
- Refreshments
109Raps of the Gavel their Purposes
- One rap
- Everyone should be seated
- Two raps
- The meeting is called to order
- Three raps
- Everyone should stand up