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Lesson
15: Drawing the Bearing Cap in Ortho, Iso and 3d |
FIG. 15a (the Bearing Cap)
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The bearing cap is a part that is easy to understand.
A bearing is a surface where a rotating shaft revolves
within. Bearings are in all kinds of machinery, automobiles,
aircraft, trains and myriad of other motorized vehicels.
That which supports a bearing is a bearing cap of
one configuration or another.
The bearing cap like allot of different kinds of
machine parts as had an evolution and what we see
today with this kind of part displays new designs
and innovations.
As a Draftsman, knowledge of part names and their
function is as important as creating the prints for
their production.This experience lends the Draftsman
to be able to easily make changes in existing parts
for new applications.
In lesson 15 you will be drawing the Bearing Cap
as an example of an existing mechanical part with
widespread use in our world today.
Connecting Your Learning
As you work your way through this lesson, you should
reflect on the following questions:
How did the bearing cap get its name?
How is the ellipse used to obtain the shape of this
model?
How can the Isometric view be created with the trunion?
Which view will I use to extrude this model for a
3d illustration?
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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 of the
bearing cap and dimension the model.
2. Identify the isometric angles used to create isometric
views (30, 90 and 150 degrees)
3. Create an isometric view using the two useful views
of the orthographic's of the Bearing Cap.
4. Adjust the dimscale overall and linear to reflect
full scale dimensions in the ortho/iso drawing.
5. Create the 3d model of the Bearing Cap from the front
orthographic view.
6. Working with colors for visualization enhancement.
7. Using 2 views to illustrate a model.
8. Be able to use draw the ellipse to illustrate circles
and in this case a hemisphere in model.
9. Be able to illustrate a hole with a hidden line property.
Key
Terms
"click
on the key on any of these terms and it will hyperlink
to the course glossary" |
The 15th
model you will be drawing is called the Bearing Cap and
only 2 views are necessary to describe this object in
blue print: top and front views.The Bearing Cap is an
historical part and the concept has been used to hold
bearings that are involving in rotating shafts.
Insert your
Lesson 15 media disk into your CD drive and begin listening
to the avi file: lesson 15a. 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 15b you will be
creating the Isometric view of the Bearing Cap. This particular
drawing is best drawn by locating the centers of ellipses
in the central part of the model as well as the locating
of ellipses that are used for its mounting holes. Please
Insert the Media Disk and listen to lesson 15b. Below is
what your completed assignment should look like when complete.
Please Insert the Media Disk labeled Lesson
15 into your CD drive of your computer and begin listening
how to draw the 3d model of the Bearing Cap. The lesson
avi is titled Lesson 15c and below is an example of a completed
accurate model of the Bearing Cap. You will submit your
drawing using the orbit command to orient the model to its
true isometric "working view".This is what your
completed 3d assignment 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 15 assessment comprises:
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Lesson 15a submitted as a dwg. file
(10 pts.)
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Lesson 15b submitted as a dwg. file.(10
pts.)
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Lesson 15c 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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