Graphic Expression and Communication

Unit 7 Technologies 1st ESO – IES Poeta Julián Andúgar Antonio Ruiz Hernández

Graphic Expression

 We have to distinguish between:  Artistic drawing  No rules  Express feelings and emotions  Technical drawing  International standards (rules)  Transmit ideas – Represent objects

Graphic Expression

 Aims of graphic expression in Technology: 1.

To design objects or organise ideas 2.

To show our ideas to other people 3.

To make our designs attractive

Graphic Materials



Pencil.

They have a wooden case with a lead inside made of

graphite

and

clay

.

+

Graphic Materials: Pencil

 There are two types of pencil: H and B.

 Hard pencils (H)  Thin lines  Technical drawing  Soft pencils (B)  Thick lines  Artistic drawing Intermediate

Graphic Materials: Paper

  Paper can be classified by

size

,

weight

and

finish

.

Depending on the

size

we distinguish different formats:  Starting with DIN-A0 (Deustche Industrienorm): 118.9 cm A3 A4 A5 A1 A2

Graphic Materials: Paper

 Depending on the

weight

the paper is thicker or thinner.

 Depending on the

finish

we distinguish:  Rough paper  Smooth paper  Shiny paper

Drawing tools



Ruler.

We use it to measure the length of a segment.



Protractor.

We use it to measure and draw angles.

Drawing tools



Set square.

For drawing parallel and perpendicular lines. They come in two shapes:  Right-angled isosceles triangle.

 Right-angled scalene triangle

Drawing tools



Compasses.

Two connected arms, one with a sharp metal point and the other with a lead. It is used to draw circles and arcs.

Sketch, Diagram and Technical Drawing   

Sketch.

object.

Freehand. Shows first idea of the

Diagram.

Freehand. Gives more specific information: measurements, materials,…

Technical drawing:

Same information as a diagram, but using drawing tools (ruler, set squares, compasses,… or a computer) Sketch Diagram Technical Drawing

Scales 

Definition.

We use the scales to fit the objects on the drawing surface (paper).

 There are 3 types of scales:  Full Scale. We draw the life-size object. (S = 1:1).

 Scale to reduce . To draw objects bigger than the paper. (S = 1:X). Examples: S=1:2, S=1:10…  Scale to enlarge . (S = X:1). Examples: S=2:1, S=5:1,…

Dimensions  

Definition.

We use dimensions measurements of an object.

to indicate the Dimension rules   1 st .

Normally dimensions are expressed in milimeters. If not, we have to indicate the units.

2 nd .

Don’t duplicate the information (only draw the necessary dimensions).

  3 rd .

Draw the dimension centered above the dimension line. If it is vertical, draw it on the left.

4 th .

Don’t use parts of the piece as auxiliary dimension lines.

 5 th .

line If possible, no line should cross any dimension

Thank you very much for your attention!