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Chapter 6 – Pictorial Sketching

Print handoutsSelect File, PrintEdit the following selections to read:

Select the OK button

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Chapter 6 – Pictorial Sketching

Projection Systems Page 169

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Multiview vs Axonometric Projection

Page 170, Figure 6.2

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Overview Previous discussion centered on multiview

drawings -2D orthographic projections (Chap 5) Focus now on pictorial drawings which look

more like pictures than a multiview drawing (3D).– Easier to visualize design

– Sometimes added to multiview drawing for clarification

– Good for marketing, shows assembly, inspect fits, conceptual ideas

– Not good for dimensioning/manufacturing (can’t show detail)

Exploded Isometric Assembly

Isometric drawings are frequently used to show how parts assemble as in this automobile power module.

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Axonometric Projections

We will focus on isometric sketching.– Note, all angles are equal, and all line

segments are equal (cube)

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Isometric Projection vs. Sketch

Isometric projections are foreshortened because the object is tipped with respect to the viewing plane. Isometric sketches, or drawings, are not usually foreshortened because they still appear proportionate when showing the dimensions full size along isometric axis lines. It is easier just to sketch the full dimension.

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Step by Step: Isometric Sketching

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Axis, Views and Dimensions

Views?

Top

Top

Front

Front

R Side

R Side

Axis? 3D - Isometric

2D - Orthographic

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Axis, Views and Dimensions

Views?

Top

Top

Front

Front

R Side

R Side

Axis? 3D - Isometric

2D - Orthographic

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Axis, Views and Dimensions

Views?

Top

Top

Front

Front

R Side

R Side

Axis?Dimensions?

Width

Height

Depth

W D

H

3D - Isometric

2D - Orthographic

Isometric Line

Isometric Plane

Hidden LinesHidden lines are not usually shown in isometric sketches unless they are needed to show a feature that would be unclear.

Usually the orientation for the isometric drawing should be chosen so that hidden lines aren’t needed.

Holes are assumed to go completely through the object unless their depth is indicated with a note or with hidden lines.

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Axis: 1st Position VS 2nd Position

1st Position 2nd Position

W

H

D

W

H

D

1. Box in overall dimensions.

2. Which view is most descriptive? Sketch as much of it as you can.

Isometric Lines

Non-isometric Line

Non-isometric Plane

Isometric Plane

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Solid Modeling Demo Pro/ENGINEER (planes)

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Example¼” GRID

Locating Features

To locate a feature such as the upper block, make measurements from an existing corner as shown here.

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Plotting Points

3 4

2 1

2, 3, 1,4 1, 2 4, 3

1. Number the plane you want to locate.2. Number the plane in the other views.3. Locate the plane in the isometric view point by point.

Point 1:

0, 0, 0

W, H, D

0, 0, 0

0, 0, 0

1.5, 1.5, .5

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Plotting Points

3 4

2 1

2, 3, 4, 1 1, 2 4, 3

1. Number the plane you want to locate.2. Number the plane in the other views.3. Locate the plane in the isometric view point by point.

Point 1:

0, 0, 0

0, 0, 0

0, 0, 0

2

Point 2:

1 .5, 1.5, .5

1.5, 1.5, .5

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Plotting Points

3 4

2 1

2, 3, 4, 1 1, 2 4, 3

1. Number the plane you want to locate.2. Number the plane in the other views.3. Locate the plane in the isometric view point by point.

Point 1:

0, 0, 0

0, 0, 0

0, 0, 0

2

Point 2:

1

4

3

Point 3:

.5, 1.5, .5

1.5, 1.5, .5

1.5, 1.5, 1

Point 4: .5, 1.5, 1

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Plotting Points

3 4

2 1

2, 3, 1,4 1, 2 4, 3

1. Number the plane you want to locate.2. Number the plane in the other views.3. Locate the plane in the isometric view point by point.

Point 1:

0, 0, 0

0, 0, 0

0, 0, 0

2

Point 2:

1

4

3

Point 1’:

.5, 1.5, .5

1.5, 1.5, .5

.5, 2, .5

Point 4’: .5, 2, 1

1’,

, 1’

, 4’

1’

4’

4’

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Plotting Points

3 4

2 1

2, 3, 4, 1 1, 2 4, 3

1. Number the plane you want to locate.2. Number the plane in the other views.3. Locate the plane in the isometric view point by point.

Point 1:

0, 0, 0

0, 0, 0

0, 0, 0

2

Point 2:

1

4

3

Point 2’:

.5, 1.5, .5

1.5, 1.5, .5

1.5, 2, .5

Point 3’: 1.5, 2, 1

1’, 4’

, 1’

, 4’

1’

4’

3’

2’

, 2’

, 3’

2’, 3’

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Plotting Points

3 4

2 1

2, 3, 4, 1 1, 2 4, 3

1. Number the plane you want to locate.2. Number the plane in the other views.3. Locate the plane in the isometric view point by point.

Point 1:

0, 0, 0

0, 0, 0

0, 0, 0

2

Point 2:

1

4

Point 2’:

.5, 1.5, .5

1.5, 1.5, .5

1.5, 2, .5

Point 3’: 1.5, 2, 1

1’, 4’

, 1’

, 4’

1’

4’

3’

2’

, 2’

, 3’

2’, 3’

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Plotting Points1. Number points.2. Locate axis (0,0,0) (W,H,D)3. Locate each point.

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3’ 2’ 1’

3, 3’

2, 2’

1, 1’

4. Connect points.

Point 1?.75, 2, 0

Point 2?

Point 3?

1.5, 1.25, 0

1.5, 2, 0 Points

1,’, 2’, & 3’?

5. Darken appropriate lines.

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Plotting Points1. Number points.2. Locate axis (0,0,0) (W,H,D)3. Locate each point.

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3’ 2’ 1’

3, 3’

1

2, 2’

1, 1’

2

3

3’

2’

1’4. Connect points.

Point 1?.75, 2, 0

Point 2?

Point 3?

1.5, 1.25, 0

1.5, 2, 0 Points

1,’, 2’, & 3’?

5. Darken appropriate lines.

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Plotting Points1. Number points.2. Locate axis (0,0,0) (W,H,D)3. Locate each point.

13 2

3’ 2’ 1’

3, 3’

1

2, 2’

1, 1’

2

3

3’

2’

1’4. Connect points.

Point 1?.75, 2, 0

Point 2?

Point 3?

1.5, 1.25, 0

2.25, 2, 0 Points

1,’, 2’, & 3’?

5. Darken appropriate lines.

Inclined Surfaces in Isometric

Inclined surfaces can not be measured along inclined lines in an isometric sketch. To locate inclined surfaces you must make measurements along the isometric axis lines.

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Locating on a Non-isometric Plane

1

1 1

Locate the center of the circle.

Point 1 coordinates? .5, 1.0625, .75

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Locating on a Non-isometric Plane

1

1 1

1

Locate the center of the circle.

Point 1 coordinates? .5, 1.0625, .75

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Complete the Isometric

2 3

1 4

Point 1:

Point 2:

Point 3:

Point 4:

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Activities Lightly show all construction lines.

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Chapter 6 – Pictorial Sketching

Circles and ArcsPrint handoutsSelect File, PrintEdit the following selections to read:

Select the OK button

Circles in Isometric Circles appear as

ellipses when drawn in an isometric sketch.

Video clip here

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Frontal Plane

Orthographic

Frontal Plane

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Profile Plane

Orthographic

Profile Plane

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Horizontal Plane

OrthographicHorizontal Plane

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Notice Direction of Ellipses Dependent on Sketch Plane

Horizontal Plane

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Notice Direction of Ellipses Dependent on Sketch Plane

Frontal Plane

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Notice Direction of Ellipses Dependent on Sketch Plane

Profile Plane

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Notice Direction of Ellipses Dependent on Sketch Plane

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Step 4: Sketch arcs

Step 1: Select appropriate plane

Step 5: Sketch arcs

Steps to Sketching Ellipse on Frontal Plane

Tangent

Tangent

Step 2: Locate center of circle

Center lines must be parallel to Frontal plane axis lines.

Frontal planeIsometric Axis

Finished frontal plane ellipse

Center point of arc

Center point of arc

Step 6: Darken

Distance Height

Width

Step 3:Determine radius

Lines must be sketched parallel to appropriate axis lines

Radius

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BacksideBox in depth

Locate center

Sketch ellipse

Add tangent lines and darken

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Sketch the Following Soup Cans Show ALL construction lines lightly

Cylinders Ø1 X 2

1 Grid = 1/4”

Thru hole Ø.25

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Thin Object Determine appropriate plane

Locate center of hole

Determine radius Create

ellipse

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Thin Object - Backside

Sketch ellipseLocate

center lines

Box radiusDetermine depth

Darken object lines

Sketch entire ellipse?

Arcs in Isometric Sketches

Arcs are usually sketched by locating their centers and then boxing in the enclosing parallelogram. Sketch the arc tangent to the enclosing box, which is drawn along isometric lines.

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ArcDetermine appropriate plane

Locate center of arc

Determine radius

Create ellipse

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Arc – Bottom Side

Darken

Determine depth

Locate center lines and box radius

Sketch ellipse

Add tangent line

Sketch entire ellipse?

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