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):

84.1

cm

118.9 cm

A5

A1

A2

A3

A4

Graphic Materials: Paper Depending on the weight the paper is

thicker or thinner.

Depending on the finish we distinguish: Rough paperSmooth paperShiny 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. Freehand. Shows first idea of the object.

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 to indicate the

measurements of an object. Dimension rules

1st. Normally dimensions are expressed in milimeters. If not, we have to indicate the units.

2nd. Don’t duplicate the information (only draw the necessary dimensions).

3rd. Draw the dimension centered above the dimension line. If it is vertical, draw it on the left.

4th. Don’t use parts of the piece as auxiliary dimension lines.

5th. If possible, no line should cross any dimension line

Thank you very much

for your attention!