Extension 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

Extension 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

Leader 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. .

Arrowheads 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.

DIMENSIONING INCLUDES MEASUREMENTS, NOTES AND

SYMBOLS

6

1. 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

Procedures 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.

The 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.

Cartesian Coordinate System

Polar 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

Absolute 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

Boolean Commands. Union ( or ?) adds parts

together Subtract or Difference ( ? ) removes

parts or features Intersection ( or ? )

Intersects overlapping volumes into a single

feature

Purpose of a Sketch

- Quickly easily get an idea on paper
- Design sketches
- Freehand technical sketches
- Technical illustrations

Freehand Technical Sketch

Design Sketch

Technical Illustration

Sketching Lines

- Vertical lines
- Top to bottom
- Long straight lines
- Series of short straight lines

Sketching Circles Arcs

- Begin by lightly constructing a square

Sketching Angles

- Begin with 90 angle

60

45

30

Subdivide once

Subdivide twice

Sketching

- Types of Sketches
- Single-view
- Multi-view
- Pictorials

Single-view Sketching

- Technical purposes
- Front view
- Most descriptive features

Multi-view Sketching

- Technical sketch
- Front view
- Top view
- Side view

Pictorial Sketches

- Quickly communicate an idea
- Three dimensions in one view
- Width
- Height
- Depth

Pictorial Sketches

- Three (3) types
- Isometric
- Oblique
- Perspective

Isometric Sketch

HEIGHT

WIDTH

DEPTH

Isometric Sketching

- Three equally spaced axes of 120

Isometric Sketching

- Receding lines
- Typically 30 off horizontal

Isometric Sketching

- Circular shapes appear as ellipses

Isometric Ellipses

- Correct ellipse orientation

Isometric Sketching

- Non-Isometric lines
- Locate endpoints and connect

Oblique Sketch

HEIGHT

DEPTH

WIDTH

Oblique Sketching

- Front view is drawn true shape and size

Oblique Sketching

- Receding edges are usually drawn at an angle of

30, 45, or 60

Oblique Sketching

- Circles and curves drawn on frontal plane will

appear true shape and size

Perspective Sketches

2-Point Perspective

1-Point Perspective

Perspective Sketches

- Objects appear as the eye would see them
- Most realistic type of pictorial sketch
- Most difficult pictorial sketch to draw

Drafting Equipment

- Drawing board/table

Drafting Equipment

- Drawing Horizontal lines
- T-square
- Parallel edge
- Drafting Machine
- Arm/elbow type
- Track type

Drafting 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

Drafting 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.

Drafting Equipment - Scales

- Engineer (Civil)
- Mechanical drafter
- Metric
- Architecture

Drafting 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

Drafting 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

Lettering

- 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

Lettering 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

Lettering

- 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

Lettering 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

Guidelines

- 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

Types 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

Lettering 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

Drawing Lines

- Use parallel edge (or T-square) to draw

horizontal lines - Lean pencil at about 60
- Use triangles to draw vertical and inclined lines

Drawing Lines at Standard Angles

Scale 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

Reading a Mechanical Scale

- FRACTIONAL INCH SCALE (FULL SIZE)

Reading a Mechanical Scale

- FRACTIONAL INCH SCALE (HALF SIZE)

Reading a Decimal Scale

- DECIMAL INCH SCALE (FULL SIZE)

Reading a Decimal Scale

- DECIMAL INCH SCALE (HALF SIZE)

Reading a Metric Scale

- 11 SCALE (1mm DIVISIONS)

Reading a Metric Scale

- HALF SCALE (2mm DIVISIONS)

Alphabet 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)

Alphabet 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

Alphabet 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

Alphabet of Lines

- Dimension, Extension, Leader Lines
- Thin and dark
- .020 (0.5mm)
- Softer lead (F or HB)

6.125

Multiview 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

Multiview Drawing

- A system that allows you to make a

two-dimensional drawing of a three-dimensional

object

Viewing Objects

- A box is formed by six mutually perpendicular

planes of projection that are located around the

object

Viewing 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

Viewing Objects

- Unfolding the box produces an arrangement of the

six views

Choosing Views

- Most commonly used views
- Front View
- Top View
- Right Side View
- Most descriptive view is typically designated as

the Front View

Choosing 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

Object 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

Object Dimensions

- Front View
- Shows width height
- Top View
- Shows width depth
- Side View
- Shows height depth

Drawing Views of Objects

- Depth can be projected between views by using a

45 miter line

Line 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

Line Types - Hidden

- Edges that cannot be seen from a given view are

indicated by Hidden lines

Line Types - Hidden

- Drawing hidden lines
- .125 (3mm) dashes
- .0625 (1mm) spaces between dashes
- Thin .020 (.5mm)
- Dark F or HB lead

Line Types Center

- Center lines indicate axes of symmetry

Placement of Views

- Views should be visually balanced within the

working space

Steps for Centering a Drawing

- Draw in views using light construction lines

Straight Edges

- Edges that are perpendicular to a plane of

projection appear as a point

2

3

1

Straight 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

Curved 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

Inclined Surfaces

- Inclined surfaces appear as an edge in two

opposite principal views, and appear

foreshortened (not true size) in all other

principal views.

Oblique Surfaces

- Oblique surfaces do not appear either as an edge

or true size in any principal view.

Angles

- 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

Circle

- 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

Circle

- 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

Triangles

- 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

Triangles

- Right Triangle
- One of the angles equals 90
- Hypotenuse
- The side of a right triangle that is opposite the

90 angle

Quadrilaterals

- 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

Quadrilaterals

- Rhombus
- All sides are equal length and opposite angles

are equal - Rhomboid
- Opposite sides are equal length and opposite

angles are equal

Regular Polygons

- Pentagon
- Five sided polygon
- Hexagon
- Six sided polygon
- Octagon
- Eight sided polygon

Regular Polygons

- Distance across flats
- Measurement across the parallel sides of a

polygon - Distance across corners
- Measurement across adjacent corners of a polygon

Solids

- Prism
- Right Rectangular
- Right Triangular

Solids

- Pyramid
- Torus

Geometric 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

Geometric Terms

- Bisect
- Divide into two equal parts
- Tangent
- A line and arc, or two arcs that touch each other

at one point only

Geometric Symbols

- Angle
- Triangle
- Radius
- Diameter

- Parallel
- Perpendicular
- Square
- Centerline

R

Terms 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

Terms Definitions

- Minutes
- The official written record of what was said and

done in a meeting

Terms 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

Terms Definitions

- Second
- An indication by a member that he or she wants to

consider the motion just proposed by another

member

Terms Definitions

- Minority
- Less than half
- Majority
- More than half
- Quorum
- The number of members needed to be present to

legally transact business

Motions 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

Steps 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

Steps 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

Order of Business

- Opening
- Call to order, emblem ceremony, pledge to flag)
- Roll Call
- Reading of Secretarys minutes
- Treasurers report
- Committee reports
- Standing
- Ad Hoc

Order of Business

- Unfinished business
- New business
- Program
- Speaker, film, etc
- Adjournment
- Refreshments

Raps 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