1. Explain
orthographic and multiview projection. pp. 215-218
2. Identify
frontal, horizontal, and profile planes. pp. 218-219
3. Identify
the six principal views and the three space dimensions.
pp. 224-225
4. Apply
standard line practices to multiview drawings and sketches. p. 228
5. Create a
multiview drawing by sketching or CAD. pp. 231-240
6. Identify
normal, inclined, and oblique planes in multiview drawings. pp. 248-250
7. Represent lines, curves, surfaces, holes, fillets, rounds,
chamfers, runouts, and ellipses multiview sketches. pp. 251-262
8. Explain
the importance of multiviews. pp. 219-222
9. Identify limiting elements, hidden features, and the intersection
of two planes in multiviews. pp. 251-262
10. Apply
visualization by solids and surfaces to multiviews. pp. 282-286
11. Visualize 3-D objects as multiview projections. pp. 271-282
1. Define orthographic projection.
A
parallel projection technique in which the plane of projection is positioned
between the observer and the object and is perpendicular to the parallel lines
of sight. p197
2. How is orthographic projection different from perspective
projection? Use a sketch to highlight
the differences.
Perspective
projection places the viewer at a finite (rather than infinite) distance from
the object. Being a finite distance away
creates projection lines which are not parallel and create distortions in the
projected object which mimic how the object is perceived. pp197-198
3. Define multiview drawings. Make a simple multiview sketch of an
object.
Multiview
drawings use orthographic projection to create two or more views of an object
(three is standard). The views of the
object are defined by the positions of the planes of projection relative to the
object. p199-201
4. Define frontal, horizontal, and profile planes.
The
frontal plane is typically the first plane established and shows the width and
height dimensions of the object. The
horizontal plane shows the depth and width dimensions while the profile plane
shows the depth and height dimensions.
The planes are all mutually perpendicular. pp199-201
5. List the six principal views.
Front,
top, right side, left side, bottom, and back. pp202-204
6. Define fold lines.
The
imaginary hinged edges of the glass box between the planes of projection. They are labeled on the drawing by the
initials of the planes of projection (e.g. the fold line between the horizontal
and frontal planes would be labeled H/F). p204
7. List the space dimensions found on a front view, top view, and
profile view.
Front:
width and height; top: width and depth; profile (right and left side): depth
and height. p205
8. Define a normal plane.
A
surface which is parallel to one of the three principal planes of projection
and perpendicular to the other two. This
surface will be seen in its true size and shape in one view and as edges in the
other two. p227
9. Define an inclined plane.
A
surface which is perpendicular to one of the three principal planes of
projection and inclined to the other two.
This surface will be seen as an edge in one of the views and
foreshortened in the other two. p229
10. Define an oblique plane.
A
surface which is inclined (not parallel) to all three principal planes of
projection. This surface will be seen
foreshortened in all principal views. p229
11. List the eight rules of orthographic projection.
Listed
in Summary, p267.
12. Why is visualization
important in engineering and technical graphics? Is it useful in any other
fields? Are you born with the ability to visualize, or is it learned?
Visualization
is critical to being able to formulate and solve spatial/graphic problems
mentally. It also assists in planning
the construction of drawings, sketches, and CAD models. You are both born with, and can develop,
visualization ability. p246
13. What is the relationship between faces and edges in the
visualization of an object?
Edges
are the lines that form the boundary between two faces of an object. pp249-250
14. Do planar and curved surfaces reveal themselves differently on an
object?
Curved
surfaces reveal limiting elements which represent the farthest outside feature
of the curved surface. p250
15. Explain the different visual results of additive and subtractive
combinations of two solids. Are there
ways of arranging additive or subtractive combinations such that the resulting
object doesn't look any different?
The
additive combination of two solids shows the resultant unique volume occupied
by both the original solids. With a
subtractive combination, the result shows the overlapping volume of the two
solids removed from the first solid. If
the second (subtractive) volume is a null object, the result would be the same.
pp251-252
16. What are the differences in the way normal, inclined, and oblique
faces are visualized? How are cutting
planes used to generate these faces?
A
normal face is seen in its true size and shape while the inclined and oblique
faces are seen foreshortened along either one or two of their axes,
respectively. A cutting plane parallel
to one of the primary projection planes of an object will create a normal face. If this cutting plane is rotated about one
axis, it will create an inclined face, while if it is rotated about two axes,
it will create an oblique face. pp253-254
17. Define a development. How is
it used in visualization?
A
development can be thought of the flattened skin of a solid. Developments are used to visualize the true
size an shape of faces and the relationship of faces to each other on the
object. Developments can also be used to
show the differences between planar, single-curved, and double--curved
surfaces. pp257-258
18. Name the person credited with demonstrating
multiview projections in a book published in 1528.
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