isometric projections eg

8/13/2019 Isometric Projections EG

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Isometrics

Axes equallyseparated (120)H, W, and Dmeasurements are truesize along iso. axes

Angles must be locatedby coordinatesCircles appear asellipses on all surfaces


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Isometric projection: axes

The 3 axis meet at A,B form equal angles of 120deg and they are called Isometric AxesOA is vertical, OB is inclined at 30deg to theright, OC is inclined at 30deg to the left

Any lines parallel to these Isometric Line Any planes parallel Isometric Planes


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Iso-lines & Iso-planes: examples


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Non-isometric lines

Non-isometric lines are the lines that are not parallel to any of the iso-lines.They are drawn by transferring the distance of X or Y from multi-viewto iso-view, not the actual length itself.

L is orthogonalnot equal to L inisometric


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Isometric angles & non-iso lines

Example of producing non-isometric lines.The position of point Z isobtained in the isometricview, by transferring thedistance of X and Y.


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Drawing iso-circles

To draw an iso-circle, onleft plane, Diameter 20mm

(a) Draw centre lines, vertical& 30deg to left.

(b) Draw (construction line)20mm square box. Thecentre lines should divide

each side by half.

(c) Draw straight lines; 1-2 & 1-3 and 2-5 & 2-6.(d) Point 7 is the intersection between line 1-2 & 2-5, and similarly point 8, 1-3 & 2-6 on the other

side.(e) Set your compass to the distance 7-2, draw an arc with centre at point 7, from point 2 to point 5.

Do the same on the other side.(f) Set your compass to the distance 1-2, draw an arc with centre (1), from (2) to (3).

(a)

12

3

4

5

6

7

8

2

5

4

5

6

(b) (c)

(d)(e) (f)


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Isometric Ellipses


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Sketching isometric cylinderStart by drawing the bounding box.The front end of the cylinder is sketched using the previous technique.

The far end of the cylinder is a partial iso-circle. Sketch until meeting thetangent with the two straight lines.


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Producing Isometric Sketches

Sketch an isometric box. Sketch the view on each faces, starting withisometric lines.

Add in non-iso lines and other detailsDarken all visible lines.


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6.4 Producing Isometric drawing


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IsometricSketching


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2. Define an isometric axis.

3. Sketching the enclosing box.

4. Estimate the size an and relationship of each

details.

5. Darken all visible lines.

1. Place the object in the position which its shapeand features are clearly seen.

Sketch from an actual object


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STEPS

1. Positioning object.

2. Select isometric axis.3. Sketch enclosing box.

4. Add details.

5. Darken visible lines.

Sketch from an actual object


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1. Positioning object.

2. Select isometric axis.

3. Sketch enclosingbox.

4. Add details.

Note In isometric sketch/drawing), hidden lines are omit tedunless they are absolutely necessary to completely

describe the object.

Sketch from an actual objectSTEPS

5. Darken visible lines.


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1. Interprete the m ean ing o f l ines /areas in

multiview drawing.

2. Locate the lines or surfaces relative to isometricaxis.

Sketch from multiview drawing


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Front View

Top View

Side View

Example 1 : Object has only normal surfaces

Bottom View

Bottom

Front

Side

SideFront

Top

Regular

Reverse

W D

H

H

D W


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Example 2 : Object has inclined surfaces

W

H

D

y

x Front View

y

x

Nonisometric line


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Nonisometric line

A

A x

y

x

xB

B

AB

C

C

C

x

y

Example 3 : Object has inclined surfaces


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A

A

B

B

C D

E

D

EF

F

x

y

Front View

Regular

C

Example 4

Reverse


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Circle & Arc in IsometricIn 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.


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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.


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Example 5


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Irregular Curve in Isometric

1. Construct points along the

curve in multiview drawing.

2. Locate these points in the

isometric view.

3. Sketch the connecting lines.

Steps

isometric projections eg

Documents