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Lesson
3: Drawing the V-Block in Ortho, Iso and 3d |
FIG. 3a (the V-block)
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In Lesson 3 you will be drawing the V Block which
has angled surfaces. 3 views are required to describe
this part.
As you can imagine not all parts that might exist
in our complex world will have flat shapes. Many will
have angled surfaces and ledges within those angled
surfaces.
In this lesson we will be using a "projection
rectangle", to transfer surfaces from one view
to another.
Dimensioning conventions will be illustrated with
this model. One of the major conventions is "minimum
dimensions to describe a part". A Draftsman avoids
redundant dimenions.
Connecting Your Learning
As you work your way through this lesson, you should
reflect on the following questions:
How well did the projection rectangle work transferring
angled surfaces?
What are the usefull views of this part?
Can you see the use of geometry while you are drawing
in ACAD?
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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 V-block orthographic views
2. Identify the isometric angles used to create isometric
views (30, 90 and 150 degrees)
3. Dimension this model using aligned dimensions rather
than unidirectional dimensions.
4. Extrude a region to create the pieces of the model
5. Centering technique use in orthographic views displayed
in paper space.
6. Scaling orthographic's to use when creating an isometric
view
7. Be able to "box in" also called the "Glass
Box" to create an isometric model from orthographic's.
8. Put the pieces of the model together to create the
entire model.
9. Create regions that can be extruded and used to subtract
from the basic shape of the model.
Key
Terms
"click
on the key on any of these terms and it will hyperlink
to the course glossary" |
The 3rd model
you will be drawing is called the V-block because its
function is to block another object from moving. One would
find many blocks in machinery and in power equipment.
This part could be made out of allot of different materials
including metals, ceramics, plastics and wood.
Insert your
Lesson 3a media disk into your CD drive and begin listening
to the avi file: lesson 3a. You can open up both software
programs: ACAD and your media player at the same time
and toggle back and forth between screens, and be able
to draw and listen simultaneously.
Below is
an example of what your completed drawing should look
like. Pay attention to details so you can obtain all your
points for this assignment. It is always better to get
it right the first time, especially when you have what
the finished product should look like. I will mention
in the media files about the Dim-scale of the dimension
text.
The next part of Lesson 3 is creating the
Isometric view of these flat 2 dimensional images of the
v-block. This is where our talent begins to develop in conceptualizing
what this model really looks like. In this lesson you will
be scaling your orthographic views and adjusting the linear
dimscale accordingly. Common sense will say if a scale something
to half its size the dimension scale needs to be doubled.
I will explain this in the lesson disk titled Lesson 3b.
The following is what your completed assignment should look
like when completed.
Please Insert the Media Disk labeled Lesson
3 into your CD drive of your computer and begin listening
how to draw the 3d model of the V-Block. The lesson avi is
titled Lesson 3c and below is an example of a completed accurate
model of the V-Block. You will submit your drawing in South
East Isometric. This is what that 3d model looks like.
*Note:
The Lessons are best viewed with real player, or Windows
Media Player 9 for 2000 Professional
and Version 10 for XP.
After
completing each lesson attach your drawing to an email and
send to your Instructor's email.
email:
losimilar@yahoo.com
Your
Text Book and Reading Assignments
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Text:
Autocad Drafting by
Grout, Resetarits and James
Use
this text as a reference to the media disks that you
are using for the Semester.
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.)
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Lesson 3c 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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e.gaudette all rights reserved_____________________________________________ |
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