Engineering 22
Section
Views-2
Bruce Mayer, PE
Registered Electrical & Mechanical Engineer
BMayer@ChabotCollege.edu
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Learning Goals
 Properly Create Section (CutAway) Views to Show Internal
Features Of Objects That Are
Not Easily Understood In
Standard Orthographic
Projection View Drawings
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Learning Goals cont
 Use and/or Apply
• How & Where to Construct the Cutting
Plane Line
• Section Lines (a.k.a. “Hatch Lines”)
• Several Types of Section Drawings
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Section Drawing Types





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
Full Section (done so far)
Half Section
Offset Section
Broken-Out Section
Revolved Section
Removed Section
Special Section
Conventions
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Full Section
 The cutting plane passes completely
through the part as a single flat plane
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Half Section
 The cutting plane only passes half way through the
part
 The other half is drawn as usual
 Hidden lines are not shown on either half of the part
 A center line is used to separate the two halves
 Mostly used on cylindrical parts
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Offset Section
 The multiview drawing is often difficult to interpret
when there are several hidden features on the object
 A sectioned view makes the object much easier to
understand
 An offset section allows the cutting plane to pass
through all of the significant internal features
 There may be several bends/kinks in the cutting plane
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Offset Section cont
 The actual part would show a new visible line
(at the edge) at the bend in the cutting plane
• Since the cutting plane bend is arbitrary, do not
show the line representing this bend in the
sectioned drawing
 Hidden lines
are NOT
shown
 Be sure to
include object
lines BEHIND
the cutting plane
Engineering 22 – Engineering Design Graphics
8
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Broken Out Section
 Only a portion of the view is sectioned
 A jagged break line is used to divide the
sectioned and unsectioned portion of the
drawing
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Revolved Section
 A cross section of the part is revolved 90° and
superimposed on the drawing
 A jagged break line may be used to divide the revolved
section from the rest of the drawing
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Revolved Section Caveats
 Superimposition of Rev-Sec
requires Removal of All
ORIGINAL Lines
Underneath the Section
 Retain the TRUESHAPE of the Rev-Sec
Regardless of the LineDirection in the VisibleView
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Removed Section
 Similar to the revolved section
except that the sectioned
drawing is not superimposed
on the drawing but placed
adjacent to it
 The view and the cutting
plane are labeled (Sec. A-A)
 The removed section may be
drawn at a different scale
• Very Useful for Detailing Small
Parts or Features
Engineering 22 – Engineering Design Graphics
12
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Intersections - Windows
a) The Offset of the intersection
from the Visible Lines is
SMALL or Negligible
•
Can DisRegard the True
Projection and Align to Vis-Lines
b) The Larger Intersection Does
Have a Substantial Offset
From the Visible Lines
•
Engineering 22 – Engineering Design Graphics
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Use the True-Projection to
position the intersection
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Intersections - PortHoles
c) The Offset of the intersection
from the Visible Lines is
SMALL or Negligible
•
Can DisRegard the True
Projection and Align to Vis-Lines
d) Larger Intersections
•
•
Engineering 22 – Engineering Design Graphics
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For the Smaller Hole Use Tube
OD (R1) and ID (r1) Arc at Depth
Found by True Projection
For Hole K, rk = r1, SemiEllipses
of Intersection appear as
Straight-Lines
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Special Sections
 There are special rules (conventions) that are followed
to make some parts more understandable
 Some features are rotated to their TRUE RADIAL
position in sectioned views
 The object is difficult to
understand using standard
multiview drawings where
hidden lines are used to
represent internal features
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Special Sections cont
 Many Times If a part is sectioned as it would actually
appear if cut, the details of Features such as ribs and
holes may not be clear
 Since the goal is to make the drawing easy to interpret
the drawing is modified by the following std conventions
• The cutting plane shows that the features are revolved to their
true radial position
• Hidden features are not shown
• The sectioned drawing
produced is a DISTORTED, but
CLEARER, picture of the object
• The section drawing appears
as a full section
• The arrows show the direction
of the view
Engineering 22 – Engineering Design Graphics
16
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Special Sections cont
 Ribs/Webs are not
sectioned when the
cutting plane
passes through
them lengthwise
 Ribs are sectioned
if the cutting plane
passes through
them at other
orientations
Engineering 22 – Engineering Design Graphics
17
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Special
Sections
cont
 The side view is replaced by a full section view
 The cutting plane shown in the Front view shows the
direction of the line of sight
 The holes and ribs have been revolved to their true
radial position
 The ribs are not sectioned in this orientation
 The section lines are all drawn at the same angle
since the object is one solid part
Engineering 22 – Engineering Design Graphics
18
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Conventional Breaks
 Use Conventional Breaks to Shorten an
Elongated Object
 “Jagged” Lines are used to Break Non-Circular
Cross-section Objects
 “S” Breaks are Preferred for Cylindrical Objects
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Demo – Pipe Intersection
 Let’s make a
Cross Section for
a Drilled, ThickWalled Pipe
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Final Result
Engineering 22 – Engineering Design Graphics
21
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
All Done for Today
Blue Print
CrossSec
Circa 1862
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Engr/Math/Physics 25
Appendix
f x   2 x  7 x 
9x  6
3
2
Bruce Mayer, PE
Licensed Electrical & Mechanical Engineer
BMayer@ChabotCollege.edu
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Intersect Demo
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Intersect Demo cont
Engineering 22 – Engineering Design Graphics
25
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Hatch Procedure-1
Engineering 22 – Engineering Design Graphics
26
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Hatch Procedure-2
 Hatch
DiaLog
Box
4
Engineering 22 – Engineering Design Graphics
27
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Hatch Procedure-3
 Pick Hatch Areas by
Clicking ONCE
ANYwhere within
the Region
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Hatch Procedure-4
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt
Hatch Procedure-5
 All Done
Engineering 22 – Engineering Design Graphics
30
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-12_Section-Views-2.ppt