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 Diedric system  2.5 Marking and standardizing Unit 2.Drawing applied to technology

2.1 Drawing materials and instruments 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 m 2 (A0) four times by half the longest side.

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 Wood cover

2.1 Drawing materials and instruments Pencil hardness The more clay it contains the harder the lead will be. We use letter H for hard pencils and letter B for soft ones. Hard: H Soft: B Very hardHardMediumSoftVery soft 6H5H4H3H2HHHBB2B3B4B5B6B less clay More clay Technique drawArtistic draw

2.1 Drawing materials and instruments Mechanical pencils They hold a graphite lead. They can be used for technical drawing (if used )with a soft lead. ERASERS Erasers are made of rubber, they absorb graphite and erase it.

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 trianglular set squares A 45 degree A 60 degree

2.1 Drawing materials and instruments How 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

2.1 Drawing materials and instruments Activity :Draw a chessboard using the set square. The separation between squares is 2 cm! square 16 cm

2.1 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

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

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

2.1 Drawing materials and instruments The Compass It is used for drawing circles and angles Advice: sharpen the lead tip by rubbing it on a fingernail file

2.2 DRAFT AND SKETCH DRAFT: It is a free hand drawing (just with a pencil). We show an idea or object without totally defining it. Page 41

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

2.2 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 Page 41

2.2 DRAFT AND SKETCH Activity: draw a sketch of your home cupboard.

2.2 DRAFT AND SKETCH the Sketch

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 Drawing size The Real size Page 38

2.3 Drafting scale 1200 reality 1cm drawing 1: cm measured on the drawing is equivalent to 1200cm in reality Page 38

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 Real drawn Real

2.3 Drafting scale Enlargement 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 2:1 Draw ing Real Safety pin

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 Highwide Drawn2 Real1101 Real 2:1

2.3 Drafting scale Scale 1:2 Highwide Drawn1 Real2101 2:1 Real 1:2

2.3 Drafting scale Scale 1:4 Highwide Drawn1 Real4101 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 LongHigh Drawn14,52,5 Real cm 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: 20cm 1 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 on your notebooks? lengthwidth Classroom620cm480cm Desk72cm54cm

ClassroomLongwide Drawn16,24,8 Real DesksLongwide Drawn10,720,54 Real 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: 20cm 1 hand: 10cm

15feet= 300cm 20 pies = 400cm habitaciónlenghtWide bedroom Desk150 Bed10070

2.4 Diedric system

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

2.4 Diedric system The projection or VIEW consists of drawing just what we see when we are perpendicular to the object and to the plane Page 28

2.4 Diedric system To 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 Floor view Profile view

Draw the left profile, floor and front view of your pencil case.

2.4 Diedric system Diedric 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 profile Right profile floor front

2.4 Diedric system Remember: 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 Diedric system Exercise: Draw the front, left profile and floor views of the class chair

2.4 Diedric system Exercise: Draw the front, profileand floor views of the class chair

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

2.4 Diedric system

2.4 Diedric system Exercise 11: Complete the views of the following objects Page 31

2.4 Diedric system Exercise 11: Complete the views of the following objects

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

2.4 Diedric system Insert video

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

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

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

2.4 Diedric system

2.5 Marking and standardizing The 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

2.5 Marking and standardizing Measure line Auxuliary Line Measure Reference line

2.5 Marking and standardizing Outside thick continuous line Thick discontinuous line for a hidden edge

2.5 Marking and standardizing Marking : indicating the real dimensions above the object

2.5 Marking and standardizing Activity: draw these views indicating which rules are broken Correct Wrong Correct Wrong Correct Wrong Correct 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: see page 37

2.5 Marking and standardizing Auxiliary lines  We place them perpendicular to the measure lines  They cross the measure line a little bit  They never cut the measure line

2.5 Marking and standardizing Activity: draw these views indicating which rules are broken Correct Wrong

2.5 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

2.5 Marking and standardizing Activity: draw these views indicating which rules are broken Correct Wrong

Activity: Draw the front, left profile and floor views of your pencil marking the measures 2.5 Marking and standardizing

Let’s revise the important terms

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 Diedric system  2.5 Marking and standardizing Unit 2.Drawing applied to technology

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.