DIEDRIC SYSTEM

2.4 Diedric system

2.4 Diedric system The diedric system represents the objects using a perpendicular projection on a plane

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

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 Profile view Floor view Front view Front view Floor view Profile view

Draw the left profile, floor and front view of your pencil case.

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 round, that is, the left profile is situated on the right front floor Left profile Right profile floor front

2.4 Diedric system Remember: 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 Exercise: Draw the front, left profile and floor views of the class chair

2.4 Diedric system Exercise: Draw the front, profile and floor views of the class chair

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 Exercise 11: Complete the views of the following objects Page 31

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

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 Insert video

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.

2.4 Diedric system Exercice: draw the right profile, front and floor views of these objects

2.4 Diedric system

2.4 Diedric system

2.5 Marking and standardizing The standardizing is the group of rules that defines technical drawing. For example: For paper size we use the DIN rule: A0,A1,A2… 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

2.5 Marking and standardizing Reference line Measure Measure line Auxuliary Line

2.5 Marking and standardizing Outside thick continuous line Thick discontinuous line for a hidden edge

2.5 Marking and standardizing Marking : indicating the real dimensions above the object

2.5 Marking and standardizing Activity: draw these views indicating which rules are broken Wrong Wrong Wrong Wrong Correct Correct Correct Correct

2.5 Marking and standardizing. Marking follows some rules: see page 37 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 enlongated, they go from one side to the other

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 Activity: draw these views indicating which rules are broken Wrong Correct

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

2.5 Marking and standardizing Activity: draw these views indicating which rules are broken Wrong Correct

2.5 Marking and standardizing Activity: Draw the front, left profile and floor views of your pencil marking the measures

Let’s revise the important terms

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

Vocabulary Paper size Cellulose Clay, graphite, lead Hard and soft pencils Erasers, technical pencil Sixty and forty-five degree rules Sketch, draft, free hand drawing, measures Scale, real and drawn size, reduction, enlargement scales To be reduced 100 times… Length, height, width Long, high, wide.