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Lesson
3: Orthographic's
and Isometrics of the Clamp
Lever |

Modeled and animated by Taylor
Swanson 2004
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Engineering Drafting is explored by the use of ACAD
2002. The above simple model is called the clamp lever
and its application is in securing a part to a machine
where there is a mechanical advantage. The word lever
indicates that there is a mechanical advantage that
is occurring. Below there are key words and you can
look up the word mechanical advantage and the word
lever.
The Clamp Lever is a difficult model to draw and
requires the use of multiple construction lines and
the use of the "Glass box" to produce an
accurate drawing.
Connecting Your Learning
As you work your way through this lesson, you should
reflect on the following questions:
What is the meaning of a lever?
What is the meaning of "mechanical advantage".
How is the "Glass Box Technique" useful
in Engineering Drafting?
Why is it important that all useful views are represented
in orthographic's.
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The State of Arizona has assembled Drafting
standards to make sure that Instruction is thorough
and well thought out by the instructor. By clicking
on the hyperlink below will upload to your browser window
the entirety of these standards. The standards that
are addressed in this lesson are below the hyperlink.
1.0 USE BOARD DRAFTING EQUIPMENT,
INSTRUMENTS AND MEDIA.
2.0 DEMONSTRATE SKETCHING, LETTERING,
AND LINE SKILLS.
- 2.1 Demonstrate freehand sketching skills for drafting
applications.
- 2.2 Demonstrate lettering skills.
- 2.3 Demonstrate line work.
6.0 DEMONSTRATE GEOMETRIC CONSTRUCTIONS
- 6.1 Measure Geometric Constructions.
- 6.2 Develop Geometric Constructions.
8.0 APPLY BOARD DRAFTING SKILLS TO COMPUTER-AIDED
DESIGN/DRAFTING (CADD)
- 8.1 Demonstrate computer skills for a CADD system.
- 8.2 Create dimensional CADD entities.
- 8.3 Create 3 dimensional CADD drawings.
The State of Arizona has also assembled Math
standards and many of these apply directly to
the vocational subject area of Drafting. Drafting
is a very precise discipline and the use of mathematics
is integral to design and manufacturing. Below are
the math standards that are involved in this lesson
1M-P1. Compare and contrast
the real number system and its various subsystems
with
regard to their structural characteristics
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PO 2. Compare subsets of the
real number system with regard to their properties
(commutative, associative, distributive, identity,
inverse and closure properties)
1M-P2. Construct, interpret and
demonstrate meaning for real numbers and absolute
- PO 3. Solve real-world distance problems using
absolute value
- PO 4. Determine, among the solutions to a real-world
problem, which, if any, is reasonable
- PO 2. Define absolute value as the distance from
the origin
4M-P1. Interpret and draw three-dimensional
objects
- PO 1. Sketch prisms, pyramids, cones, cylinders
and spheres
- PO 2. Classify prisms, pyramids, cones, cylinders
and spheres by base shape and lateral surface shape.
- PO 3. Recognize the three-dimensional figure represented
by a two-dimensional drawing.
- PO 5. Make a model of a three-dimensional figure
from a two-dimensional drawing and make a two-dimensional
representation of a three-dimensional object (models
and representations include scale drawings, perspective
drawings, blueprints or computer simulations)
4M-P4. Deduce properties of,
and relationships between, figures from given
assumptions
- PO 1. Find similarities and differences among
geometric shapes and designs using a given attribute
(e.g., height, area, perimeter, diagonals and angle
measurements)
- PO 2. Identify arcs, chords, tangents and secants
of a circle
- PO 3. State valid conclusions using given geometric
definitions, postulates and theorems
- PO 4. Represent pi as the ratio of circumference
to diameter
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Lesson
Objectives
By the end of this lesson you should be
able to:
1. Draw the orthographic views and dimension
according to ASME14.5 using ACAD 2002.
2. Identify the isometric angles used to create isometric
views (30, 90 and 150 degrees)
3. Understand how to use the commands of : line, copy,
move, the @ command and vectoring,
4. Draw an Isometric view from orthographic views.
5. Center orthographic models in paper space using 1.5"
between views.
6. Identify the working view of a model and its front,
top and side views.
7. Using the scale command correctly for 1/2 scale orthographic's.
Key
Terms
"click
on the key on any of these terms and it will hyperlink
to the course glossary" |
The following
is a detailed illustration of the Clamp Lever with all the
required dimensions to replicate the part. In this lesson
you will be creating the Orthographic and Isometric Projection
of this model. Please insert Lesson 3 Media Disk into the
CD drive of your computer and listen to how this object
is drawin in both Orthographic and Isometric.
The following is what your completed Orthographic Projection
of the Clamp Lever should look like before submission.Notice
that we have used different line colors to keep track of
hidden and center lines projected onto the side view.Notice
the scale is 3/8 scale in layout_c. You will learn how to
draw full scale and scale down layout_c to fit the largest
view of the models we draw orthorgaraphically.
Click on image
for larger view

The
following screen capture shows half scale orthographic's
and a full scale Isometric of the Corner Stop. This picture
is an example of what your completed assignment should look
with a print preview.
Click on image
for larger view

*Note: The Lessons are best
viewed with real player and you can download the latest
version by clicking on the words
real
player.
After completing
each lesson attach your drawing to an email and send to your
Instructor:losimilar@yahoo.com
or if you are taking this course in the classroom Print your
assignment and pass it in to be graded.
Your
Text Book and Reading Assignments
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Text:
Engineering Drawing and Design
by Jensen and Helsel
Use
this text as a reference together with the media disks that
you are using for the Semester. I you are a classroom student
media is available on either of 3 Servers.
Lesson 3 assessment comprises:
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Lesson 3a submitted as a dwg file (10
pts.)
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Lesson 3b submitted as a dwg file.(10
pts.)
Rubrics for Grading: The drafting
standards for assessing the quality and accuracy of your drawings
are as follows: Neatness, Accuracy and Lines and Lettering.
One half of one point (.5) will be taking off your score in
relation to NALL.
Submit by email attachment all
of the above lessons as dwg. files and send to your Instructor
whose mail address is. losimilar@yahoo.com
Your Instructor will grade your
drawings within 24 hours and email you back the grade/assessment
of your work. You should take allot of pride in your work.
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