Unit 2 Drawing appplied to technologies
71
Unit 2.Drawing applied to technology
Transcript of Unit 2 Drawing appplied to technologies
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 m2 (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 hardnessThe 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 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
2.1 Drawing materials and instruments
Mechanical pencilsThey hold a graphite lead. They can be used for
technical drawing (if used )with a soft lead.
ERASERSErasers are made of rubber, they absorb graphite and erase it.
2.1 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
2.1 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
2.1 Drawing materials and instruments
Activity :Draw a chessboard using the set square. The separation between
squares is 2 cm!
square16 cm
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 instrumentsThe CompassIt 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 sizePage 38
2.3 Drafting scale
1200 reality1cm drawing
1:1200
1 cm measured on the drawing is equivalent to 1200cm in reality
Page 38
2.3 Drafting scaleScale 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
2:12:1Drawing
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, 1:41cm
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
4.5c
m
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= 72cm3hands x 18cm/hand= 54cm31 feet x 20cm/foot= 620cm24 feet x 20cm/foot=480cm
2.3 Drafting scale
Which scale could we use to draw the classroom and your desks on 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 wideDrawn 1 0,72 0,54Real 100 72 54
2.3 Drafting scaleLet’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
15feet= 300cm20 pies = 400cm
habitación lenght Wide
bedroom 330 200
Desk 150 150
Bed 100 70
2.4 Diedric system
2.4 Diedric systemThe diedric system represents the objects
using a perpendicular projection on a plane
2.4 Diedric systemThe 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 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
Draw the left profile, floor and front view of your pencil case.
2.4 Diedric systemDiedric RulesThe front is usually indicated with an arrowThe 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 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 Diedric systemExercise: Draw the front, left profile
and floor views of the class chair
2.4 Diedric system Exercise: Draw the front, profile and
floor views of the class chair
2.4 Diedric systemWhere do we have to be situated to see these objects like circles?
2.4 Diedric system
2.4 Diedric systemExercise 11: Complete the views of the following objects
Page 31
2.4 Diedric systemExercise 11: Complete the views of the following objects
2.4 Diedric systemExercise 11: Complete the views of the following objects
2.4 Diedric systemExercise 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 systemInsert video
2.4 Diedric systemActivity: draw the front, floor and right
profile views of this figure colouring each face in one colour.
2.4 Diedric systemActivity: draw the front, floor y left profile views of this figure colouring
each face in a different colour.
2.4 Diedric systemExercice: draw the right profile, front and
floor views of these objects
2.4 Diedric system
2.4 Diedric system
2.5 Marking and standardizingThe 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 standardizingActivity: 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: 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 standardizingActivity: 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 standardizingActivity: 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.
