Unit 2.Drawing applied to technology - Netmon · Unit 2.Drawing applied to technology Whatare wegoingtoseein thisunit? 2.1 Drawingtoolsandhow touse them 2.2 Draftsandsketches 2.3

Unit 2.Drawing applied to technology

Unit 2.Drawing applied to technology� What are we going to see in this unit?

� 2.1 Drawing tools and how to use them

� 2.2 Drafts and sketches

� 2.3 Scale

� 2.4 Diedric system: Views of an object

� 2.5 Marking and standardizing

It is all about images

2.1 Drawing materials and instruments

Pencil� A pencil has a lead covered with wood. The lead is made with graphite and clay

clay

Graphite

Lead

Woodcover


Pencil hardnessThe more clay it contains the harder the lead willbe. We use letter H for hard pencils and letterB for soft ones.

Hard: HSoft: B

Very hard Hard Medium Soft Very soft

6H 5H 4H 3H 2H H HB B 2B 3B 4B 5B 6B

less clayMore clay

Technique draw Artistic draw


Mechanical pencilsThey hold a graphite lead. They can be used for

technical drawing with a hard lead.

ERASERSErasers are made of rubber, they absorb graphite

and erase it.

Video


Paper� Paper 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.

2.1 DRAWING TOOLS

THE RULER

It 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 triangular set squaresA 45 degree

A 60 degree

Other Drawing tools

2.1 Drawing materials and instrumentsHow to draw vertical and parallel lines with the

set square

Vertical:Parallel:

Activity: Draw the set squares in yournotebook so you can see them in both

positions


Activity :Draw a chessboard using the set square . The separation between squares is

2 cm!

square16 cm

16 cm


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

combining the set squares


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 153

2.1 Drawing materials andinstruments

Drawing angles exercise: you have to obtain, 45º, 75º, 90º, 120º angles combining the set squares


The CompassIt is used for drawing circles and angles

Advice: sharpen the lead tip by rubbing it on a fingernail file

2.2 DRAFT AND DIAGRAMS

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

� Is the initial drawing which shows the fundamental elements of a design and reflects its main concepts


�ATTENTION! � A DRAFT IS NOT A

BAD DRAWING AND A DIAGRAM IS NOT A GOOD DRAWING !!!!!!

2.2 DRAFT AND DIAGRAM

DIAGRAM: It has more information than a rough draft. It includes the measures, therefore it shows the precise size and shape similar to the final drawing.

measure

2.2 DRAFT AND SKETCH

� Activity: draw a sketch of your homecupboard (closet).


theSketch

Sketching to communicate

2.3 Drafting scale

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

A model uses a reduction scale

2.3 Drafting scale

1:2

The Drawingsize

The Real size

2.3 Drafting scale

1200 reality1cm drawing

1:1200

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

Page38

E 1:1200

2.3 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

2.3 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

Safetypin

2.3 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, 1:4 1cm

10cm

2.3 Drafting scale

Scale 2:1

High wide

Drawn 2

Real 1 10 1

Real

2:1

2.3 Drafting scale

Scale 1:2

High wide

Drawn 1

Real 2 10 1

2:1

Real

1:2

2.3 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

2.3 Drafting scale

Scale exercise

• This drawing is 4,5cm long and 2,5 cm high, if we have used a 1:100 scale How high and long is the real car?

4.5cm

2.5cm

2.3 Drafting scale

Scale 1:100

Long High

Drawn 1 4,5 2,5

Real 100 450 250

4.5cm

2.5cm

2.3 Drafting scale

• Activity:

Let’s draw a plan of your classroom using your feet and your hands applying the suitable scale to draw it

1 foot: 20cm1 hand: 10cm

31 feet are equivalent to 620cm

24 feet are equivalent to 480cm

4,5 hands = 45cm

3,5 hands=35cm

Therefore we have

2.3 Drafting scale

4hands x 18cm/hand= 72cm

3hands x 18cm/hand= 54cm

31 feet x 20cm/foot= 620cm

24 feet x 20cm/foot=480cm

2.3 Drafting scale

Which scale could we use to draw the classroom and your desks in your notebooks?

length width

Classroom 620cm 480cm

Desk 72cm 54cm

Classroom Long wide

Drawn 1 6,2 4,8

Real 100 620 480

Desks Long wide

Drawn 1 0,72 0,54

Real 100 72 54

2.3 Drafting scale

Let’s use the 1:100 scale, so the drawing will be 100 times smaller than reality

2.3 Drafting scale

• Homework:

Draw a plan of your bedroom using your feet and your hands. Apply a 1:25 scale to draw it

1 foot: 20cm1 hand: 10cm

2.4 Diedric system

2.4 Dihedral system

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

2.4 Dihedral 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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2.4 Dihedral systemTo define an object we only need 3 views, floor, front and

profile:� Floor view : from the top of the object� Front view: facing the object� Profile view: from the side

Profile view

Floor view

Front view

Front view

Floor view

Profile view

2.4 Dihedral system

Dihedral Rules� The front is usually indicated with an arrow� The views distribution

� The front is always on top of the floor

� The profile is situated the other way round, that is, the left profile is situated on the right

front

floor

Left profileRight profile

floor

front

2.4 Dihedral systemRemember:� The same height: the object has the same height on the

floor and on the profile views� The same width: on the front and on the floor views� The same depth: on the floor and on the profile views

2.4 Dihedral system

� Exercise: Draw the front, left profileand floor views of the class chair

2.4 Dihedral system

� Exercise: Draw the front, profile and floor views of the class chair

2.4 Dihedral system

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

2.4 Dihedral system

2.4 Dihedral systemExercise 11: Complete the views of the following objects

2.4 Dihedral system

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

hidden line

2.4 Dihedral system

� Insert video

2.4 Dihedral system

Activity : draw the front, floor and right profile views of this figure colouring each face in one colour.

2.4 Dihedral system

Activity : draw the front, floor and left profile views of this figure colouring each face in a different colour.

2.4 Dihedral system

� Exercice: draw the right profile, front andfloor views of these objects

2.4 Dihedral system

Dimensioning

�Standardizing is the group of rules that defines technical drawing.

� For example:� For paper size we use the DIN rule: A0,A1,A2…� The lines are :○ Thick continuous lines: are used to outline objects○ Thick discontinuous lines: indicate hidden lines○ Thin continuous lines: are used for auxiliary measures

and reference lines

� Dimensions are written on the drawingoutside the object.

� Never write the dimension over theobject unless there is no other option.

Dimensioning

� Dimension lines should be 10 mm awayfrom the drawing or another dimensionline.

� Dimension shoud be placed at thecentre of the dimension line, but neverthrough the middle of a dimension line.

� Dimensions can be written: horizontallyso that they are parallel to the botton ofthe page, aligned so that they are parallel to the dimension line.

Dimensioning

2.5 Marking and standardizing

Dimension line

Auxiliary Line

Measure

Reference line

2.5 Marking andstandardizing

Outside thickcontinuous line

Thick discontinuousline for a hiddenedge


Marking : indicating the real dimensions above the object

2.5 Marking andstandardizing� Activity : draw these views indicating

which rules are broken

Correct WrongCorrect WrongCorrect WrongCorrect Wrong

2.5 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 enlongated, they go from one side to the other

Marking follows some rules


� Auxiliary lines� We place them

perpendicular to the measure lines

� They cross the measure line a little bit

� They never cut the measure line



Correct Wrong


� The measures:� We indicate the real

measure in milimetres, but“mm” is never written

� They are placed above themeasure line, never underit

� We only use the extrictlynecessary measures



Correct Wrong

2.5 Marking and standardizing

� Activity : Draw the front, left profile andfloor views of your pencil marking themeasures

�Let’s revise the important terms

Unit 2.Drawing applied to technology� What are we going to see in this unit?

� 2.1 Drawing tools and how to use them

� 2.2 Drafts and sketches

� 2.3 Drafting scale

� 2.4 Dihedral system

� 2.5 Marking and standardizing

Vocabulary � Paper size � Cellulose� Clay, graphite, lead� Hard and soft pencils� Erasers, technical pencil� Sixty and forty-five degree rules� Sketch, draft, free hand drawing, measures� Scale, real and drawn size, reduction,

enlargement scales� To be reduced 100 times…� Length, height, width� Long, high, wide.

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Unit 2.Drawing applied to technology - Netmon · Unit 2.Drawing applied to technology Whatare wegoingtoseein thisunit? 2.1 Drawingtoolsandhow touse them 2.2 Draftsandsketches 2.3