Transcript Slide 1

Innovation and Inventions
Unit 2
ETP 2006 – Jeff Pegg
This material is based upon work supported the National Science foundation under Grant No.
0402616. Any opinions, findings, and conclusions or recommendations expressed in this material
are those of the author(s) and do not necessarily reflect the view of the National Science
Foundation (NFS).
Drafting is the part of industry concerned with the preparation
of drawings needed to develop and manufacture
modern-day products.
•Drafting is frequently called a “UNIVERSIAL LANGUAGE”
because it communicates ideas in graphic or picture form.
•Like other languages, symbols that have special and specific
meanings are used to accurately describe the shape, size, type
of material, finish and fabrication of an object.
•The symbols have been standardized over most of the world
making it possible to interpret and understand drawings made
in other countries.
We will be doing Mechanical Drawing, which means we will
be using tools to complete the drawings.
Drawing from “Exploring drafting basic fundamentals” John R. Walker
Any object in nature has how many sides?
6
What are the views?
Top
Left
Side
Back
Front
Right
Side
Bottom
The three (3) that we will use are Front, Top and Right Side.
Measuring
•If your drawings are to be made accurate, you
must be able to make accurate measurements.
•The ruler that we will be using is measured to
1/16 of an inch.
•I know that most of you could measure
something that is 4 inches long.
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2
3
4
5
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But what happens when the measurement
is less that one inch?
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You will see that there are smaller lines
between the Inch marks.
We will be going from the largest marks (1 Inch) to the
smallest marks ( 1/16 of an inch) on a ruler.
As we are going from the largest to smallest each time we are
dividing the number by ½.
So we will take the 1 inch mark and make it into a fraction.
Which is 1/1 and we will divide it by 2.
Or take the fraction and multiply by 1/2
1/1X1/2= 1/2
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2
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The next shortest line is ½ X ½ = ¼.
1/4
3/4
1/2
2/4
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1
The next shortest line is ¼ X ½ = 1/8.
1/8
3/8
1/4
2/8
7/8
5/8
3/4
1/2
6/8
2/4
4/8
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The smallest line that we will use is:
1/8 x ½ = 1/16
1/16
3/16
5/16
1/8
2/16
7/16
9/16
3/8
1/4
2/8
4/16
5/8
1 0/16
6/16
1/2
2/4
4/8
0
11/16
8/16
13/16
15/16
7/8
3/4
14/16
6/8
12/16
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Basic drawing that you will be doing.
1. Orthographic projection (Three View)
2. Pictorial
A. Isometric
B. Oblique (Cavalier)
C. Perspective (One Point)
Orthographic Projection.
Permits a three-dimensional object to be drawn
on a flat sheet of paper having only two dimensions.
Pictorial Drawings
A pictorial drawing shows the likeness of the
object as viewed by the eye.
Isometric Drawings
An isometric drawing shows an object as
is. All lines which show the width and
depth are drawn full length.
Also Isometric drawing are drawn to the 3
base lines which are 30 degrees to the left,
30 degrees to the right and vertical or 90
degrees.
90.0°
30.0°
30.0°
Oblique Pictorial Drawings
An Oblique drawing is a pictorial drawing similar to an
isometric drawing, except one surface, the longest
dimension or front is parallel to the picture plane
(and is drawn in true shape and size).
There are three types of Oblique drawings
1. Cavalier Oblique - depth axis lines are drawn at full
scale.
2. Cabinet Oblique – depth axis lines are drawn at onehalf scale.
3. General Oblique – depth axis lines vary from one-half
to full scale.
The angle is usually 45 degrees.
Cavalier Oblique
Cabinet Oblique
General Oblique
Perspective Drawings
Perspective drawing is a drawing used by an
Architect, Artist, or Draftsman to show an object as
it would appear to the eye from a certain location.
There are two types of perspective drawings:
1. One point perspective.
2. Two point perspective.
There is one major point or points used. These are
called vanishing points. All lines are drawn to
vanish points.
A perspective drawing is like standing on a road and
looking at the horizon and the road looks like it
comes together, but it doesn’t.
Vanishing
Point,
To draw the depth, select one line
measure the depth and then draw a
vertical and horizontal line to the other
depth lines.
Vanishing
Point
Vanshing
Point
To draw the depth, measure on depth axis
and the draw a line vertical and the other point
to the vanishing point.
Standards:
Standard 8: Students will develop an understanding of the attributes of design.
Benchmark E Design is a creative process that leads to
useful products and systems.
Standard 9: Students will develop an understanding of engineering design.
Benchmark F Design involves a set of steps, which can be preformed in
different sequences and repeated if needed.
Standard 11: Students will develop abilities to apply the design process.
Benchmark H Apply a design process to solve problems in
and beyond the laboratory- classroom.
Benchmark J Make two-dimensional and three-dimensional
representations of the designed solution.