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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 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 hard Hard Medium Soft Very soft
6H 5H 4H 3H 2H H HB B 2B 3B 4B 5B 6B
less clay More clay
Technique draw Artistic 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 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.
See picture in Page 41
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.
See picture in Page 40
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
The difference between them is that the draft gives us a simple idea of the object and the sketch gives us a complete defined picture with measures
DRAFT SKETCH
2.2 DRAFT AND SKETCH
Activity: draw the draft and sketch of your pencil
2.3 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 1:500000
The Drawing size
The Real size
2.3 Drafting scale
1:2
The Drawing size
The Real size
Page 38
2.3 Drafting scale
200 reality 1cm drawing
1:200
1 cm measured on the drawing is equivalent to 200cm 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 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 2:1
Drawing
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: 1:1, 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
4.5c
m
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: 20cm 1 hand: 10cm
feet are equivalent to cm
hands = cm
Hands= cm
Therefore we have
2.3 Drafting scale
hands x 10cm/hand= cm hands x cm/hand= cm
feet x 20cm/foot= cm
feet x 20cm/foot= cm
feet are equivalent to cm
hands = cm
Hands= cm
Therefore we have
2.3 Drafting scale
Long 9 hands x 10cm/hand= 90 cm Wide 7 hands x 10cm/hand= 70 cm Long 32 feet x 20cm/foot=640 cm Wide 23 feet x 20cm/foot=460 cm
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
Real 100 620 460
Desks Long wide
Drawn 1
Real 100 90 70
2.3 Drafting scale Let’s use the 1:100 scale, so the drawing will be 100 times smaller than reality
2.4 Diedric system 07/12/2011 Drawing exam: Scale, Views and marking
2.4 Diedric system The diedric system represents the objects using a perpendicular projection on a plane
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 The projection or VIEW consists of drawing just what we see when we are perpendicular to the object and to the plane
Page 28
Floor view
Front view Right Profile view
1
2
4 5
6
Rayo proyectante
3
1
2
3
4 5
6
7
7 8
© Pedro J. Castela
Floor view
Front view Right Profile view
Floor view
Front view
Right Profile view
1
2
7
4 5
6
3
© Pedro J. Castela
Floor view
Front view
Right Profile view
1
2
4 5
6
3
7
© Pedro J. Castela
1
2
4 5 6
3
7
1
2
3
4 5
6
7
8
© Pedro J. Castela Floor view
Front view Right Profile view
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
Left Profile view
Floor view
Front view
Front view
Floor view
Left Profile view
2.4 Diedric system IMPORTANT: Follow these rules
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
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 around,
that is, the left profile is situated on the right
front
floor
Left profile Right profile
floor
front
Draw the left profile, floor and front view of your pencil case. Use a 1:4 scale
front
floor
Left profile
Draw the left profile, floor and front view of my tamagochi. Use a 1:4 scale
front
floor
Left profile
2.4 Diedric system
Insert video
2.4 Diedric system
Insert video
2.4 Diedric system
Exercise: Draw the front, left profile and floor views of the class chair
front
floor
Left profile
2.4 Diedric system
Check with your rule that all lines are matched
2.4 Diedric system
Correct with RED color your exercise and copy my picture
2.4 Diedric system Exercise 11: Complete the views of the following objects
Page 31
You have to use Pencil Rules Draw big PICTURES
2.4 Diedric system Exercise 11: Complete the views of the following objects
2.4 Diedric system Exercise 11: Complete the views of the following objects
2.4 Diedric system Exercise 11: Complete the views of the following objects
Vamos a ver cómo se dibujan las vistas de la pieza mostrada en la figura, utilizando un papel cuadriculado (cuadrícula grande), de manera que cada cuadrícula de la pieza equivale a una cuadrícula del papel.
© Pedro J. Castela Haz clic para continuar
2.4 Diedric system
A
B
Para dibujar la vista de alzado nos fijamos en cuánto mide la pieza de ancho (A = 5) y de alto (B = 6) y dibujamos un rectángulo de esas medidas. Sólo tienes que contar los cuadritos.
ALZADO
© Pedro J. Castela Haz clic para continuar
2.4 Diedric system
La cara que tenemos más cerca mide D = 2 cuadros de altura, por tanto trazamos una línea a dos cuadros de la base del rectángulo que contiene a la vista de alzado.
D
A
B
ALZADO
© Pedro J. Castela Haz clic para continuar
2.4 Diedric system
Para terminar la vista de alzado, observa que tanto la rampa como la cara vertical tienen la misma altura (4 cuadros). Sin embargo, la rampa tiene 2 cuadros de ancho y la cara vertical 3.
D
A
B
ALZADO
La cara vertical y la rampa tienen la misma altura.
© Pedro J. Castela Haz clic para continuar
2.4 Diedric system
La vista en planta se sitúa justo debajo de la vista de alzado y en ella vemos la pieza desde arriba. Sus dimensiones serán A = 5 y C = 5, es decir, un cuadrado de 5 x 5.
D
A
B
PLANTA
C
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2.4 Diedric system
Para dibujar la cara superior observemos que E = 2 cuadros. Por tanto, trazamos una línea paralela a la cara superior del cuadrado que contiene a la vista en planta, a una distancia de 2 cuadros.
D
A
B
PLANTA
E
C
© Pedro J. Castela Haz clic para continuar
2.4 Diedric system
Para dibujar la cara inferior y la rampa observemos que las dos tienen una profundidad de 3 cuadros, pero distinto ancho. Por tanto, trazamos una línea que separe ambas caras, de manera que la rampa tenga 2 cuadros de ancho.
D
A
B
PLANTA
E
C
La cara inferior y la rampa tienen la misma profundidad.
© Pedro J. Castela Haz clic para continuar
2.4 Diedric system
La vista de perfil izquierdo se dibuja a la derecha del alzado, a su misma altura. En principio, dibujamos un rectángulo de altura B = 6 y ancho C = 5 cuadros. Después borraremos las líneas que sobren.
D
A
B
PERFIL IZQUIERDO E
C
C
B
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Observemos que la cara más cercana tiene forma de L. Por tanto, la dibujamos así, teniendo en cuenta las dimensiones D = 2 y E = 2 cuadros.
D
A
B
PERFIL IZQUIERDO E
C
C
B
E
D
© Pedro J. Castela Haz clic para continuar
2.4 Diedric system
La cara correspondiente a la rampa tiene forma de triángulo rectángulo. Observa que la rampa tiene una altura de 4 cuadros y una profundidad de 3cuadros. Su longitud no importa. Para terminar, borramos las líneas que sobran.
D
A
B
PERFIL IZQUIERDO E
C
C
B
E
D
© Pedro J. Castela Haz clic para continuar
2.4 Diedric system
Este sería el resultado final. La vista de alzado y la vista en planta están en la misma vertical y tienen el mismo ancho (A), mientras que las vistas de alzado y de perfil están en la misma horizontal y tienen la misma altura (B).
© Pedro J. Castela Haz clic para continuar
2.4 Diedric system
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
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.
Tabla vistas
Completa Esta tabla
Solución
Ejercicio para casa. 46 y 48 de la página 46 : realiza el perfil derecho, alzado y planta de estas figuras
Ejercicio para casa. 46 y 48
Solución
2.5 Marking and standardizing
Marking is the standard language that engineers use to define the size, materials and properties of an object so that anyone can understand it
2.5 Marking and standardizing 2.- Lines
Measures are in mm, other units are marked 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. Dots and thin discontinuous lines: indicate a circumference or
cylinder axis
2.5 Marking and standardizing
Measure line
Auxuliary Line
Measure
Circumference axis line
Reference line
Measure line ends
Measures position
2.5 Marking and standardizing
Activity: Draw the front, left profile and floor views of these objects marking the measures. Apply the correct scale
2.5 Marking and standardizing
You have to use a frame
2.5 Marking and standardizing
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 elongated, they go from one side to the other
Marking follows some rules
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 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
Solución Tabla vistas
Ejercicio
Ejercicio para casa. 46 y 48
Ejercicio para casa. 46 y 48
Ejercicio