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Introduction

Orthographic projections are used to

represent 3D components on a flat surface

in a 2D form. The two main types are First

Angle Projection and Third Angle Projection

(TAP). We will focus on TAP.

Three views are usually used to indicate the

shape fully: A Plan, a Front view and a Right

view. Complex shapes can require a fourth;

Left view.

Orthographic 6

6a Orthographic representation

Isometric representation

Front

Plan

Right

Left

Front

Plan

RightLeft

Plan

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Setting up a Third Angle Projection

Fig 6.1a shows the positioning of views

relative to each other.

Study the diagrams on sheet 6.11 then

complete the exercises on the following

sheets in this chapter.

Orthographic 6.1

Isometric representation

6.1a Third Angle Projection

Front RightLeft

Plan

Orthographic 6.11 Setting up a TAP drawing

1 On an A4 sheet of paper draw the plan first in a faint pencil line, allowing space below to

draw the front, left and right views.

2 Allow 30 mm between the bottom line of the plan and the top line of the front view and

project all widths down from the plan.

3 Project 45° swing lines from the outside edges of the front view. 4 Project all depths horizontally from the plan on to the swing lines then vertically down

to the right side view. Project heights horizontally from the front view to the right side

view. Repeat process to establish the left view.

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45°45°

swing line

30mm

Plan

Front RightLeft

Plan

Front

Plan

Front

Third Angle Projection

Fig 6.2b shows a component drawn in

Third Angle Projection with one view missing.

Complete by drawing the missing view.

Refer to fig 6.2a for dimensions; e.g. the

front view is seven units wide.

6.2a Isometric representation

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Orthographic 6.2

Plan

Front RightLeft

6.2b Third Angle Projection

Plan

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Third Angle Projection

Orthographic 6.3

Complete the TAP drawings

by adding the missing views.

Show all hidden detail with

dotted lines. Refer to figs 6.3a

and 6.3b for dimensions.

Draw directly onto this sheet

using a pencil and ruler. Draw

in ink when you are certain

your solutions are correct.

6.3a

6.3b

Front RightLeft

Plan

Front RightLeft

Use the squares on the grid to

complete the TAP drawings.

Use a ruler and pencil and

show all hidden detail with

dotted lines. Refer to figs

6.4a and 6.4b for dimensions.

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Orthographic 6.4 Third Angle Projection

Plan

Front RightLeft

Plan

Front RightLeft

6.4a

6.4b

Pen Project

Photo Album Project