Engineering 22
Auxiliary
Views-1
Bruce Mayer, PE
Registered Electrical & Mechanical Engineer
BMayer@ChabotCollege.edu
Engineering 22 – Engineering Design Graphics
1
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Chp7 Learning Goals
 To Develop The Skill to Generate Views
That Show Inclined And NonGlassBox
(Oblique) Surfaces In TRUE Shape In
Multiview Drawings
 To Be Able to Integrate into Standard
MultiView Drawings these AUXILIARY
VIEWS to Clarify the Description of The
Object
Engineering 22 – Engineering Design Graphics
2
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Auxiliary Views
 AUXILIARY views are often used to show INCLINED
and OBLIQUE surfaces in TRUE SIZE.
• Inclined and oblique surfaces do not show true size in the
standard views.
 Auxiliary views are OrthoGraphic views taken from a
direction of sight OTHER than top, front, right side,
left side, bottom, or rear.
 PRIMARY auxiliary views are projected onto a plane
that is perpendicular to only one of the PRINCIPAL
planes of projection and is inclined to the other two.
 SECONDARY auxiliary views are projected from
PRIMARY auxiliary views.
Engineering 22 – Engineering Design Graphics
3
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Auxiliary Views - Graphically
 Principal faces of the above object are NOT
Parallel to the standard planes of projection
 The auxiliary view shows the TRUE Size
and Shape of the hole feature
Engineering 22 – Engineering Design Graphics
4
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Glass Box with Auxiliary Plane
P
 Note Folding Line is PARALLEL to Inclined Surface P
• The Aux Plane Shows Surface P in TRUE Size
– Observe the FORESHORTENING in the Top View
– The Aux Plane is Perpendicular to the Frontal PLANE
Engineering 22 – Engineering Design Graphics
5
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Auxiliary Vs. Principle Views
 Principle planes
• Horizontal (Top and Bottom view)
• Frontal (Front and Back view)
• Profile (Left and Right Side view)
 Auxiliary views
• Definition: An OrthoGraphic view that is
projected onto a plane that is NOT parallel to
ANY of the PRINCIPLE planes
• Purpose: To show the TRUE shape of a detail
that does not lie in one of the principle planes
Engineering 22 – Engineering Design Graphics
6
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Recall Fold-Line Method
 A Fold Line (Hinge) May Be Placed Between Adjacent
Views To Aid In The Construction And Interpretation Of
Multiview Drawings
 Projection Lines Are Always Perpendicular To Fold Lines
 The Distance From a Fold
Use Dist-Xfer
INSTEAD of
Line To Any Specific Point
Mitre-Line
On An Object Is The Same
For Any Related Views
(ex. Top and Side View)
• CRITICAL for DISTANCE
TRANSFER
 Fold Lines Represent a
90° Rotation In Viewpoint
Engineering 22 – Engineering Design Graphics
7
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Aux View Construction – Fold Ln
1.
2.
3.
4.
For the Given Example Drawing With H/F Fold Line
Select a Direction (Line) of Sight (LoS)
Perpendicular to The NonOrthographic Surface
Draw Folding Line F/1 Perpendicular to the LoS
Project Perpendicular Lines Across the Folding
Line To Transfer Feature Distances Used to
Construct The Aux-View. Label Vertices if Needed
Engineering 22 – Engineering Design Graphics
8
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Aux. V. Construction Summary
1. Determine the Line of Sight sight Necessary
To Produce The Desired Auxiliary View
Show in TS
 Front
Engineering 22 – Engineering Design Graphics
9
 Side
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Aux. V. Construction Summary
2. Identify surfaces on the object. Locate
vertices by Dist –Xfer and project to Aux-V.
Project each
point
Engineering 22 – Engineering Design Graphics
10
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Vertex Numbering
 Vertex Numbering is More Critical
to Aux-View Construction Than to
Principle-View Development
 Recall The Vertex Numbering
System From §7.6 in Text
• If a POINT is VISIBLE in a Given
View, Then the Number is Placed
OUTSIDE of the Corner
• If a POINT is HIDDEN, Then Place
The Number on the INSIDE of the
Vertex
Engineering 22 – Engineering Design Graphics
11
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Primary Auxiliary View
 Definition: Any view that is projected from (adjacent
to) one of the principle views and which is not
parallel to any of the principle planes
 A primary auxiliary view is perpendicular to Only
ONE of the principle planes
 ANY INCLINED surface may be shown in TRUE
Shape in the Appropriate primary auxiliary view
 If the fold line for an auxiliary view is PARALLEL to
the EDGE VIEW of an Inclined surface then the
Inclined surface will appear in TRUE shape in the
auxiliary view
Engineering 22 – Engineering Design Graphics
12
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Projection Planes
 A fold line represents the Edge
View of the projection plane for
the adjacent view (Frontal in
this case)
 A line appears in true-length if it
lies in a plane parallel to the
projection plane
 A line which is not parallel to the
projection plane appears
foreshortened
 A line which is perpendicular to
the projection plane appears as
a point
Engineering 22 – Engineering Design Graphics
13
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Lines
TL
X
TL
TL
Engineering 22 – Engineering Design Graphics
14
 A line which is Parallel to a
fold line will appear TRUE
Length in the adjacent view
 A true length line which is
PERPENDICULAR to a
fold line will appear as a
POINT in the adjacent view
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Lines
 All views adjacent to a
point view of a line will
show the line in true length
 A line which does not
appear true length in any of
the principle views is called
an OBLIQUE line
Engineering 22 – Engineering Design Graphics
15
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Surfaces
TS
Engineering 22 – Engineering Design Graphics
16
 A Surface appears in “true
shape” (undistorted) if it is
PARALLEL to the projection
plane
 A surface appears as an edge
parallel to the fold line in all
views adjacent to the true
shape view of the surface
 If any line on a surface appears
as a point then the surface will
appear as an edge
 A surface which does not
appear as an edge in any of the
principle views is called an
OBLIQUE surface
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Aux. View Classification
Proj from
FRONT
View
Proj from
TOP
View
Proj from
SIDE
View

DEPTH of the Object
Shown in TRUE
LENGTH

HEIGHT of the
Object Shown in
TRUE LENGTH
Engineering 22 – Engineering Design Graphics
17

WIDTH of the Object
Shown in TRUE LENGTH
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Reverse Construction
 To Construct a Regular View That Contains
ForeShortened Lines/Surfaces or Ellipses It is often
More Efficient to FIRST Construct the TRUE-Length
Auxiliary view (use dist & offset to xfer “a” or “b”)
• The Regular View Can then Be constructed Using Std Methods
Engineering 22 – Engineering Design Graphics
18
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Reference Planes
 A REFERENCE Plane is formed by moving the FOLD
LINE INTO the body of the object
 The Location is ARBITRARY → Drawer Chooses
• Typical Locations → CenterLine, Object EDGES
Engineering 22 – Engineering Design Graphics
19
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Partial Auxiliary Views
Compare to
Slide-17
 PARTIAL Auxiliary Views are frequently used. The
entire view may be unnecessary and often is difficult to
read. Partial views should be connected to the view
from which it is projected by a centerline or reference
line so that it does not appear lost and unrelated to the
other views. A break line can be used to indicate that
the view is a partial view.
Engineering 22 – Engineering Design Graphics
20
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Auxiliary Sections
 Often An OFF-ANGLE SECTIONAL VIEW is more
Informative Than a Normal Projection View.
 Auxiliary Sections are Constructed by Combining AuxView Projection Techniques With the
Previously Described Sectioning Methods
Engineering 22 – Engineering Design Graphics
21
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Descriptive Geometry
 Gaspard Monge of France Developed
“Descriptive Geometry” in Late 18th Century
 Successive Auxiliary Views Constitute the Basic
Technique of DG
Must go “One View
Back” for Dist-Xfer
Engineering 22 – Engineering Design Graphics
22
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Descriptive Geometry cont

DG Uses auxiliary views to solve
engineering problems. These four auxiliary
views are basic to solving problems in
descriptive geometry
1.
Auxiliary view to show the true length of a line.
2.
3.
4.
Auxiliary view to show the point view of a line.
Auxiliary view to show the edge view of a plane.
Auxiliary view to show the true size of a plane.
Engineering 22 – Engineering Design Graphics
23
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
True Length of a Line
 A line will show TRUE length
in a plane of projection which
is PARALLEL to the line.
 To show a line in true length,
make the FOLD LINE
PARALLEL to the LINE in
question.
 Transfer FL-to-Pt distance
from “One View Back”
Engineering 22 – Engineering Design Graphics
24
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Point View of a Line
 A line will show as a POINT
view when projected onto a
plane PERPENDICULAR to
a TL View.
 To show a point view,
choose the direction of
sight parallel to the line
where it is shown in true
length (FL is  TL View).
 Xfer Dist from One View
Back
Engineering 22 – Engineering Design Graphics
25
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Edge View of a Plane
 A planar surface will show
ON-EDGE in a plane of
projection which shows
any LINE that lies entirely
WITHIN THE PLANE as a
POINT view.
 Choose the direction of
sight parallel to a TL line
lying in the plane (FL is 
to TL Line)
Engineering 22 – Engineering Design Graphics
26
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
True Size of a Surface
 A surface shows
TRUE SIZE when
projected onto a
plane PARALLEL to
it.
 Choose the line of
sight perpendicular
to the edge view of
the plane.
Engineering 22 – Engineering Design Graphics
27
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
Dihedral Angles
 The angle between two planes is called a
DIHEDRAL ANGLE
 Use an auxiliary view to show dihedral angles
in true shape → “Sight Down” the Vertex Line
Engineering 22 – Engineering Design Graphics
28
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
AutoCAD Example
 Given Triangle ABC and The Associated Frontal
& Profile Views Find:
• True Size Drawing of Triangle ABC
• The Area of the TS-Triangle Circumscribing Circle
Given Scale
– 1:160
– Notice the SuperScript
Notation to Indicate View
Engineering 22 – Engineering Design Graphics
29
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
autoCAD Example - Solution
 Draw Horizontal
Construction Lines to
Verify Views as Front
& Side
• OK → Draw F/P
Folding Line
 Profile View Shows
as STRAIGHT LINE
• Must be an EDGE
VIEW of the Triangle
plane
Engineering 22 – Engineering Design Graphics
30
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
AutoCAD Example – Solution.2
 Since Profile View is
EV, The LoS for TS
will be  to EV
• Thus Strike P/1 FL to
Right of Profile View
 Using FL P/1 Extend
Construction Lines
into Aux View
 In Front-V Measure
Offset Distances to
Locate Pts in Aux-V
Engineering 22 – Engineering Design Graphics
31
Connect
Dots
 NOTE: Aux-View No.
1 is a.k.a. “1-Space”
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
AutoCAD Example – Solution.3
 Draw TS Triangle in Aux View-1 
 Use Geometric Construction to Make Circle
• Construct -Bisectors from Two Sides to Locate
Circle-Center; use ACAD “3P” option to Draw circ.
• Use Ruler to measure Circle Diameter on Drawing
TRUE Size
Engineering 22 – Engineering Design Graphics
32
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
AutoCAD Example – Solution.4
 Calculate REAL-World Area
for Circle
2

4
A


d
 For Any Circle cirle
 Scale Diameter
• [1 dwg-mm] = [160 RealWorld-mm]
d real
160 RW  mm
 48 dwg  mm 
 7680 RW  mm  7.68m
1 dwg  mm
 Finally the Real World Area
A   7.68m 
2
Engineering 22 – Engineering Design Graphics
33
4  46.32 m
2

Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
aCAD Example – Distortion Factor
 Use CAD To Calc The Area of the FrontV
(ForeShortented) and AuxV (True Size)
Triangles
 Calc Linear Foreshortening Factor
DF  AFS ATS  543 627  93.06%
Engineering 22 – Engineering Design Graphics
34
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt
All Done for Today
Auxilliary
Views




NORMAL SURFACES are either vertical or horizontal planes that are parallel to the the six principal
planes of projection or normal views.
INCLINED SURFACES are sloping upward or downward at some angle to the horizontal plane of
projection or top view.
ANGLED SURFACES are vertical surfaces that are at some angle to the front, back or side views.
OBLIQUE SURFACES are at some angle to ALL sides of the object
Engineering 22 – Engineering Design Graphics
35
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.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
36
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-13_Aux_View-1.ppt