B6
Prepare Orthographic Drawings
Information Sheet
return
to Core Schedule
Textbook: Engineering Drawing and Design,
3rd Edition,
Madsen, Folkestad, et al.
The following links are to PDF versions of this
chapter. This is provided as a convenience if you have not yet obtained the
textbook from the bookstore. Other chapters will not be provided in this format.
You will need access to the textbook for the remainder of the course.
Textbook
- pages 171 to 179
Textbook
- pages 180 to 185
| 1. |
Identify
the need for Multiviews
See textbook page 171
|
Ortho Exercise
Below |
| 2. |
Identify
the six views
See textbook page 173
|
Ortho Exercise
Below |
| 3. |
Define
the three principle views
See textbook page
174
Plan (top) view
The plan view is the view that is projected on to the top
plane, or the view that would be seen when stationed above the object. The
top view is
often called the plan view because this is the view used to plan, or
layout, the architectural scheme in a building.
Frontal
(front elevation) view
The frontal view is the view that would be projected on to the
front plane, or the view that would be seen when stationed in front of the
object. It is sometimes called the front elevation because the view is of
the entire view.
Profile
(or side) view
The profile, or side view is the view that would be projected on to the
side plane, or the view that would be seen when stationed at the side of
the object.
Three
Principle Views
These 3 views are called the principle views because they are the only
3 required to show all the features of an object. We need only 3 views
because we live in a 3-dimensional world (length, width, height).
The decision whether to use the right side view or the left side view
depends on the object we are describing.
If the object is symmetrical we will always choose the right side view. If
the object has more features on the left side that will better help to
describe the object, we will choose the left side view.
|
Ortho Exercise Below |
| 4. |
Use
miter lines
See textbook
pages 174, 175, 179A
mitre line is a line at 45 degrees used to “bend” the projected lines
from the top view to the side view.
In
AutoCAD we could simply copy and rotate
the top view
|
Ortho Exercise
Below |
| 5. |
Select
appropriate views
See textbook pages 175-176
|
Ortho Exercise
Below |
| 6. |
Identify the
intersection of 2 planes
A
line occurs whenever 2 planes intersect at any anlge between 0 and 180
degrees.
|
Ortho Exercise
Below |
| 7. |
Project
circles and arcs
|
Ortho Exercise
Below |
| 8. |
Identify third
and first angle projection
|
Ortho Exercise
Below |
| 9. |
Understand
the characteristics of these objects in orthographic views:
See textbook page
183
a)
Inclined surfaces
An inclined surface is a plane that is not in one of the
three orthographic planes (top, front, side) or is not horizontal
or vertical.
An inclined surface will appear as a foreshortened
(distorted)
plane in the 2 views it cuts through, and as a
true-length line in the other view.
b)
Oblique (skew) surfaces
Oblique, or skew
planes cut across all 3 orthographic planes. They will appear as a
fore-shortened plane with the same number of sides in all 3 views.
Note:
It is helpful to remember that lines that are parallel to each
other will be parallel to each other in every view.
c)
Hidden details and linetype used
Hidden details are features that are not visible (cannot be seen) in a
particular view. We indicated these with a hidden (dashed) line.
_
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
d)
Circles and curves
Remember
that a line occurs when 2 planes intersect (see 6.7). A circle, or curved
surface has an infinite number of planes intersecting, but they have no
area, so we will never see a line.
Consequently,
curved surfaces are peculiar in that they will appear the same in two
views.
|
Ortho Exercise
Below
Ortho Exercise
Below |
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10. |
Recognize
and create border templates for Imperial and Metric drawings
|
Go To Exercise |
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