Unit 1.Drawing applied to technology

What are we going to see in this unit?1.1 Drawing materials and

instruments1.2 Drafts and sketches1.3 Drafting scale1.4 Diedric system1.5 Marking and standardizing1.6 Perspective systems

Unit 1.Drawing applied to technology

1.1 Drawing materials and instruments

PaperPaper is made of cellulose that is obtained

from trees The paper size that we use is A4 . It is the

result of dividing 1 m2 (A0) four times by half the longest side.

1.1 DRAWING TOOLS

THE RULERIt is a precision tool that makes it possible to measure and to transfer a distance.

TRIANGULAR SET SQUARE A set square is a tool for drawing perpendicular (vertical) and parallel lines and for obtaining angles. There are 2 types of trianglular set squares

A 45 degree

A 60 degree

1.1 Drawing materials and instrumentsHow to draw vertical and parallel lines

with the set square

Vertical: Parallel:

Activity: Draw the set squares in your notebook as you can see

them in both positions

1.1 Drawing materials and instruments

Drawing angles: we can get 15º, 30º, 45º, 60º, 75º, 90º, 120º, 135º…angles

combining the 30º, 45º , 60º and the 90º angles from the set squares

You don't have to copy them because you can find them in your text book on page 25

1.1 Drawing materials and instruments

Drawing angles exercise: you have to obtain, 45º, 75º, 90º, 120º angles

combining the set squares

Solution

1.1 DRAFT AND SKETCH

DRAFT: It is a free hand drawing (just with a pencil). We show an idea or object without totally defining it.

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1.1 DRAFT AND SKETCH

ATTENTION! A DRAFT IS NOT A BAD DRAWING AND A SKETCH IS NOT A GOOD DRAWING !!!!!!

1.1 DRAFT AND SKETCH

The sketch: It is a free hand drawing too, but it includes the measures, therefore it shows the precise size and a shape similar to the final drawing.

measure

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1.3 Drafting scale

We define scale as the relation between the drawing size and the real object

A model uses a reduction scale

1.3 Drafting scale

1:2

The Drawing

size

The Real size

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1.3 Drafting scale

1200 reality1cm drawing

1:1200

1 cm measured on the drawing is equivalent to 1200cm in reality

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1.3 Drafting scale

Scale types:• Reduction scale: it is used to

represent big objects, so they can be drawn on paper– We usually use: 1:2 1:5 1:10…

In this example we have reduced 1000 times the real size of the tree

1:1000 Realdrawn RealReal

1.3 Drafting scaleEnlargement scale: it is used to

represent small objects so we can see them on paper

– It is used: 2:1 5:1 10:1 …

In this example the drawing is two times the real object

2:12:1

Drawing

Real

Safety pin

1.3 Drafting scale

An example of scale application• Let’s draw a pencil that is 10cm

high and 1cm wide using different scales: 2:1, 1:2, 1:41cm

10cm

1.3 Drafting scale

Scale 2:1

High wide

Drawn

Real 10 1

Real

2:1

1.3 Drafting scale

Scale 1:2

High wide

Drawn 1

Real 2 10 1

2:1

Real

1:2

1.3 Drafting scale

Scale 1:4

High wide

Drawn 1

Real 4 10 1

Real

2:1

1:2

1:4

Real

2:1

1:2

Real

1:2

2:1

Real

1:2

1.3 Drafting scale

Scale exerciseUsing an electronic microscope we can see a virus that is 1,5pm. This picture is 6 cm long, do you know the scale used to draw it?

1.3 Drafting scale

Scale ???:1

Long

Drawn ????? 6 1010pm

Real 1 1,5 pm

1.4 Diedric system

1.4 Diedric system

The diedric system represents the objects using a perpendicular projection on a plane

1.4 Diedric systemThe projection or VIEW consists of drawing just what we see when we are perpendicular to the object and to the plane

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1.4 Diedric system

Insert video

1.4 Diedric system

Insert video

1.4 Diedric systemTo define an object we only need 3 views, floor, front

and profile:Floor view: from the top of the objectFront view: facing the objectProfile view: from the side

Profile view

Floor view

Front view

Front view

Floor view

Profile view

1.4 Diedric system

Diedric RulesThe front is usually indicated with an

arrowThe views distribution

The front is always on top of the floorThe profile is situated the other way around,

that is, the left profile is situated on the rightfront

floor

Left profile

Right profile

floor

front

1.4 Diedric systemRemember:The same height: the object has the same height on

the floor and on the profile viewsThe same width: on the front and on the floor viewsThe same depth: on the floor and on the profile

views

1.4 Diedric systemExercise: Draw the front, left profile

and floor views of the class chair. This chair is 80 cm high, 40 cm wide and 40 cm deep. Use the proper scale

1.4 Diedric system

Where do we have to be situated to see these objects like circles?

1.4 Diedric systemExercise 11: Complete the views of the following objects

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1.4 Diedric system

Non visible lines: when we know there is a hidden line we have to draw it using a discontinuous line

hidden line

1.4 Diedric system

Activity: draw the front, floor and left profile views of this figure coloring each face in one color. Apply a proper scale

30cm

100cm

100cm

20cm

1.4 Diedric system

Exercice: draw the right profile, front and floor views of these objects

100cm

1.5 Marking and standardizingThe standardizing is the group of

rules that define objects in technical drawing.

1.5 Marking and standardizingUsing a standard language we can define the size, materials and properties of an object so that anyone can read it

1.5 Marking and standardizingThere are several elements used to draw a object, but we are going to see only the most relevant:

1.PaperFor paper size we use the DIN rule: A0,A1,A2…

1.5 Marking and standardizing

2.- Lines

The lines are:Thick continuous lines: are used to outline objectsThick discontinuous lines: indicate hidden linesThin continuous lines: are used for auxiliary measures

and reference lines.Dots and thin discontinuous lines: indicate a

circumference or cylinder axis

1.5 Marking and standardizing

Measure line

Auxuliary Line

Measure

Circumference axis line

Reference line

1.5 Marking and standardizing

Marking : indicating the real dimensions above the object

1.5 Marking and standardizing.

The measure lines: We place them parallel to

the edge and slightly separated

They are limited by the auxiliary lines

The arrows are thin and elongated, they go from one side to the other

Marking follows some rules

1.5 Marking and standardizing

Auxiliary linesWe place them

perpendicular to the measure lines

They cross the measure line a little bit

They never cut the measure line

1.5 Marking and standardizing

The measures:We indicate the real

measure in milimetres, but “mm” is never written

They are placed above the measure line, never under it

We only use the extrictly necessary measures

Measure line ends

Arrow: ends in a aux. Line

Line: ends in a measure line

Dot: ends in a line objectMeasures position

1.5 Marking and standardizing

Activity: draw these views indicating which rules are broken

Correct Wrong

Exercice: Make a file of this object, drawing its views including all measures, AND SCALE

Assembled sizeWidth: 79 cmWood widht: 5 cmDepth: 39 cmHeight: 79 cmMax load/shelf: 13 kg

1.6 Perspective systems

Which one of these objects is a cube?

1.6 Perspective systemsThey are all cubes,

but drawn with different

perspectives

1.6 Perspective systemsBut, what is a perspective?It is an approximate representation, on a flat surface (such as paper), of an image as it is perceived by the eye.

1.6 Perspective systemsThe simplest one is the one point perspective, where all

lines go to one vanishing point

Vanishing Point

Video link

Acceso directo a 1punto habitacion.lnk

1.6 Perspective systemsIf we want to create a more realist drawing we have to

use a two point perspective

Now we have two vanishing points, where the left and right lines go

1.6 Perspective systemsFinally, we have the three points

perspective, that creates an almost real view

Lines go to the left, the right and the floor

vanishing points

1.6 Perspective systemsRegular objects are drawn using the

caballera perspective

All lines are parallel to Z, X

or Y axes

1.6 Perspective systems

X and Y axes form a 90º angle and Z axe form a 135º angle

Z axe

Y axe

X axe

90º

90º

135º

1.6 Perspective systemsIn X and Y axes measures are applied directly. But, in order to create a human vision of the object, Z axe form a 135º angle and measures have a ½ reduction

½ reduction in all z measures

1.6 Perspective systems

Exercise. You have to present the standard file of this object that has to describe the scale used, measures, views and caballera perspective.

Measures: Assembled sizeWidth: 79 cmDepth: 39 cmHeight: 149 cmWood width: 5 cmMax load/shelf: 13 kgStandard File Data:Name and Family nameGrade and GroupScale and unitsName of the file and short description