RATHER DRAWING DEEPAK SAMEER JHA LOVELY SCHOOL ENGINEERING WHAT DO YOU UNDERSTAND LOOKING AT THE FIGURES SHOWN BELOW SQUARE PLANE RECTANGULAR PLANE CIRCULAR DISC C Y L I ND E R C ONE ID: 596287
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Slide1
ISOMETRIC PROJECTION RATHER DRAWING
DEEPAK SAMEER JHA
LOVELY SCHOOL ENGINEERINGSlide2
WHAT DO YOU UNDERSTAND LOOKING AT THE FIGURES SHOWN BELOW?
SQUARE PLANE
RECTANGULAR PLANE
CIRCULAR
DISC
C
Y
L
I
ND
E
R
C
ONESlide3
WHAT DO YOU UNDERSTAND BY?
CUBE
CUBOIDSlide4
WHAT DO YOU UNDERSTAND BY?
IT IS NOT VERY EASY AND SIMPLE TO INTERPRET AND UNDERSTAND THE ACTUAL COMPONENT BY LOOKING AT THE ORTHOGRAPHIC PROJECTION ALONE.
SO WHAT DO WE NEED?Slide5
DESIGNER’S MIND
MODEL
DRAWING
PRODUCER’S VIEW
PRODUCER’S INTERPRETION OF THE DRAWINGSlide6
Projections: Four Basic Types
Orthographic Projections
Axonometric
Oblique
Perspective
Pictorials
Note: Isometric is a special case of AxonometricSlide7
Isometric projection is a type of an axonometric projection (or pictorial projection).
Isometric means ‘equal measur
e’
.
As
the name suggests, in isometric projection, all the mutually perpendicular plane surfaces of an object and the edges formed by these surfaces are equally inclined to a POP.
In isometric projection, only one view on a plane is drawn to represent the three dimensions of an object. This provides a pictorial view with a real appearance.
WHAT IS ISOMETRIC PROJECTION?Slide8
PRINCIPLE OF Isometric Projection
CUBE
Isometric means equal measure
All planes are equally or proportionately shortened and
tilted
All the major axes (X, Y, Z) are 120 degrees apartSlide9
A VIDEO TO UNDERSTAND WHAT CONCEPT ARE WE ATTEMPTING TO UNDERSTANDSlide10
TERMINOLOGYIsometric axes The three lines
GH
,
GF
and
GC meeting at point G
and making 120° angles with each other are termed isometric axes
. Isometric axes are
often. The lines CB,
CG and CD
originate from point C and lie along
X-, Y
- and Z-axis respectively. The lines
CB and CD
make equal inclinations of 30° with the horizontal reference line. The line
CG is vertical. Slide11
LENGTH
BREADTH
HEIGHT
LETS STANDARDIZE THE AXESSlide12
Isometric lines The lines parallel to the isometric axes are called isometric lines
or
isolines
. A line parallel to the
X-axis may be called an
x-isoline. So are the cases of y-
isoline and z-isoline
.Non-Isometric lines
The lines which are not parallel to isometric axes are called non-isometric lines or
non-isolines. The face-diagonals and body diagonals of the cube shown in Fig. 18.1 are the examples of non-isolines.
Isometric planes
The planes representing the faces of the cube as well as other faces parallel to these faces are called isometric planes or
isoplanes. Note that isometric planes are always parallel to any of the planes formed by two isometric axes.Non-Isometric planes
The planes which are not parallel to isometric planes are called nonisometric
planes or non-isoplanes
(or non-isometric faces).Origin or Pole Point
The point on which a given object is supposed to be resting on the HP or ground such that the three isometric axes originating from that point make equal angles to POP is called an origin
or pole point.
CHARACTERISTICS OF ISOMETRIC PROJECTIONSlide13
Making an Isometric Sketch
Defining Axis
30
o
30
o
60
o
60
o
Isometric AxisSlide14
NOTENO ISOMETRIC VIEW SHALL BE DRAWN WITHOUT DRAWING THE ORTHOGRAPHIC VIEWSSlide15
ISOMETRIC PROJECTION OF STANDARD FIGURESSlide16
RECTANGLESlide17
TRIANGLESlide18
PENTAGONSlide19Slide20
CIRCLESlide21
IRREGULAR SHAPESSlide22Slide23
Using construction lines to construct a cube.
Key rules!
All diagonal lines are at 30
°.
All other lines are vertical.
Keep all construction lines
very
faint.Slide24
Using a cube to create right angle triangles
1
2
3
4
Other examplesSlide25
SOLIDS
PRISM
OPPOSITE ENDS ARE EQUAL JOINED BY RECTANGULAR PLANES
Rectangular Prism (Cuboids)
PENTAGONAL PRISM
HEXAGONAL PRISMCYLINDER
PYRAMIDA PLANE ON ONE SIDE AND AN APEX ON THE OTHER JOINED BY TRIANGULAR PLANES
Rectangular Pyramid PENTAGONAL Pyramid HEXAGONAL Pyramid
CONESlide26
HEXAGONAL PRISMEDGE: 20mm and 50 mm heightSlide27
CYLINDER OF DIA 60 mm and HEIGHT 80 mmSlide28
Step 2 – Ellipse on Front Face
Lines to Tangent Points
- Lines to tangent points
- Corner to corner to get center
Tangent PointsSlide29
Step 3 – Ellipse on Front Face
Tangent Points
Sketch in ArcsSlide30
Step 3 – Ellipse on Back Face and Profile
Draw Tangent Lines for Profile
Complete Visible Part of Back Ellipse
Repeat for ellipse on rear faceSlide31
A PENTAGONAL PYRAMID OF EDGE 30mm and height 60mmSlide32
A CONE OF DIA 60 mm and HEIGHT 80 mmSlide33
Object for PracticeSlide34
Blocking in the ObjectBegin with Front Face
Front Face
Height
WidthSlide35
Blocking in the Object: Add Side Face
Height
Depth
Side FaceSlide36
Blocking in the Object: Add Top Face
Top FaceSlide37
Adding Detail Cut Outs – Part 1Slide38
Adding Detail Cut Outs – Part 2Slide39
Adding Detail Cut Outs – Part 3Slide40
Darken Final Lines - Part 4
Note:
All visible edges
will be darkenedSlide41
CHAPTER 4 : ISOMETRIC DRAWING
LOCAL PUBLICATIONS (001427383-A)
1. Three views of shaped block are shown in Figure 1. Draw a full size isometric view of the block in the direction of arrows shown. The size of grid is 10 mm x 10 mm. All hidden details need not be shown.
FIGURE 1Slide42
STEPS
1. Positioning object.
2. Select isometric axis.
3. Sketch enclosing box.
4. Add details.
5. Darken visible lines.
Sketch from an actual objectSlide43
1. Positioning object.
2. Select isometric axis.
3. Sketch enclosing
box.
4. Add details.
Note
In isometric sketch/drawing), hidden lines are
omitted
unless they are absolutely necessary to completely
describe the object.
Sketch from an actual object
STEPS
5. Darken visible lines.Slide44
1. Interprete the
meaning of
lines
/
areas
in
multiview drawing.
2. Locate the lines or surfaces relative to isometric
axis.
Sketch from multiview drawingSlide45
Front View
Top View
Side View
Example 1 :
Object has only normal surfaces
Bottom View
Bottom
Front
Side
Side
Front
Top
Regular
Reverse
W
D
H
H
D
WSlide46
Example 2 :
Object has inclined surfaces
W
H
q
D
y
x
Front View
y
x
Nonisometric lineSlide47
Nonisometric line
A
A
x
y
x
x
B
B
A
B
C
C
C
x
y
Example 3 :
Object has inclined surfacesSlide48
A
A
B
B
C
D
E
D
E
F
F
x
y
Front View
Regular
C
Example 4
ReverseSlide49
Circle & Arc in Isometric
In isometric drawing, a circle appears as an ellipse.
2. Construct an isometric square.
3. Sketch arcs that connect the
tangent points.
Sketching Steps
1. Locate the centre of an ellipse. Slide50
Circle & Arc in Isometric
3. Construct a perpendicular
bisector from each tangent point.
4. Locate the
four
centres.
5. Draw the arcs with these centres
and tangent to isometric square.
Sketching Steps
Four-centre
method is usually used when drawn an isometric ellipse with drawing instrument.
2. Construct an isometric square.
1. Locate the centre of an ellipse. Slide51
Example 5