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Unit 2.Drawing applied to technology
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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
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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.
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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
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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
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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.
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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
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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
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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
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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
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2.1 Drawing materials and instruments
Drawing angles exercise: you have to obtain, 45º, 75º, 90º, 120º angles combining the set squares
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2.1 Drawing materials and instruments
Drawing angles exercise: you have to obtain, 45º, 75º, 90º, 120º angles combining the set squares
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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
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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
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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 !!!!!!
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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
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2.2 DRAFT AND SKETCH Activity: draw a sketch of your home cupboard.
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2.2 DRAFT AND SKETCH the Sketch
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2.3 Drafting scale We define scale as the relation between the drawing size and the real object A model uses a reduction scale
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2.3 Drafting scale 1:2 The Drawing size The Real size Page 38
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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
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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
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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
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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
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2.3 Drafting scale 2:1 Scale 2:1 High wide Drawn 2 Real 1 10 Real
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2.3 Drafting scale 2:1 Scale 1:2 High wide Drawn 1 Real 2 10 Real 1:2
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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
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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
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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
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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
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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
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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
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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
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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
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15feet= 300cm 20 pies = 400cm habitación lenght Wide bedroom 330 200
Desk 150 Bed 100 70
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