1. Unit 2.Drawing applied to technology

2. 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

3. 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.

4. 2.1 Drawing materials and instruments
Pencil
A pencil has a lead covered with wood. The lead is made with graphite and clay
Lead
clay
Wood cover
Graphite

5. 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
less clay
More clay
Very hard
Hard
Medium
Soft
Very soft 6H 5H 4H 3H 2H H HB B 2B 3B 4B 5B 6B
Technique draw
Artistic draw

6. 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.

7. 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

8. 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

9. 2.1 Drawing materials and instruments
Activity :Draw a chessboard using the set square. The separation between squares is 2 cm!
16 cm
16 cm
square

10. 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

11. 2.1 Drawing materials and instruments
Drawing angles exercise: you have to obtain, 45º, 75º, 90º, 120º angles combining the set squares

12. 2.1 Drawing materials and instruments
Drawing angles exercise: you have to obtain, 45º, 75º, 90º, 120º angles combining the set squares

13. 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

14. 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

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

16. 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

17. 2.2 DRAFT AND SKETCH
Activity: draw a sketch of your home cupboard.

18. 2.2 DRAFT AND SKETCH
the Sketch

19. 2.3 Drafting scale
We define scale as the relation between the drawing size and the real object
A model uses a reduction scale

20. 2.3 Drafting scale
1:2
The Drawing size
The Real size
Page 38

21. 1:1200 1cm drawing Page 38 2.3 Drafting scale 1200 reality
1 cm measured on the drawing is equivalent to 1200cm in reality
1200 reality
1cm drawing
1:1200

22. 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
Real
Real
drawn

23. 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
Safety pin
2:1
Real
Drawing

24. An example of scale application
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

25. 2.3 Drafting scale
2:1
Scale 2:1
High
wide
Drawn 2
Real 1 10
Real

26. 2.3 Drafting scale
2:1
Scale 1:2
High
wide
Drawn 1
Real 2 10
Real
1:2

27. Scale 1:4 2.3 Drafting scale High wide Drawn 1 Real 4 10 2:1 2:1 2:1
1:2
1:2
1:2
1:2
1:4

28. 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

29. Scale 1:100 2.3 Drafting scale Long High Drawn 1 4,5 2,5 Real 100 450
4.5cm
2.5cm
Long
High
Drawn 1
4,5
2,5
Real
100
450
250

30. 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. 31 feet are equivalent to 620cm
2.3 Drafting scale
24 feet are equivalent to 480cm
Therefore we have
4,5 hands = 45cm
4hands x 18cm/hand= 72cm
3hands x 18cm/hand= 54cm
31 feet x 20cm/foot= 620cm
24 feet x 20cm/foot=480cm
3,5 hands=35cm
31 feet are equivalent to 620cm

32. 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

33. 2.3 Drafting scale Classroom Long wide Drawn 1 6,2 4,8 Real 100 620
Let’s use the 1:100 scale, so the drawing will be 100 times smaller than reality
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

34. 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

35. 15feet= 300cm 20 pies = 400cm habitación lenght Wide bedroom 330 200
Desk
150
Bed
100 70