QCAD Open Computer Assisted Design

Tema 2. El dibujo aplicado a la TecnologíaWhat are we going to learn?2.1 Basic Graphic Knoledge2.2 Relative, Absolute and Polar

coordinates 2.3 Lines, Squares, Circules2.4 Views of an object2.5 Marking2.6 Perspective

2.1 Basic Graphic Knoledge

In 2D we define a point with two Absolute coordinates:

(X,Y)P1: (X=5, Y=7)

X

Y(5,7)

-X

-Y

Grid reference

2.1 Basic Graphic Knoledge

Exercise: Using your notebook cuadricula mark this points:

0,10

10,10

10,30

20,50

30,30

30, 10

(40,10)

(40,0)

(X,Y)

Grid reference

2.1 Basic Graphic Knoledge

Exercise: Using your notebook grid mark this points:

0,10

10,10

10,30

20,50

30,30

30, 10

(40,10)

(40,0)

(X,Y)

2.1 Basic Graphic Knoledge

Exercise: Draw a line from P1 to P2.

P1 =(5,7) ; P2 =(-4,2)

P1 =(-2,1) ; P2 =(3,4)

Grid reference

2.1 Basic Graphic Knoledge

Exercise: Draw a line from P1 to P2.

P1 =(5,7)

P2 =(-4,2)

P1 =(5,7)

P2 =(-4,2)

Grid reference

2.1 Basic Graphic Knoledge

P1 =(5,7) ; P2 =(-4,2)

2.1 Basic Graphic Knoledge

Polar coordinatesThese use the distance

between points and the angle formed with the horizontal.

2.1 Basic Graphic Knoledge

Exercise: Draw a line from P1 to P2.

P1 =(5,7) ; P2 =(10, 180º)

P1 =(-4,2) ; P2 =(5, 45º)

Grid reference

2.1 Basic Graphic Knoledge

Exercise: Draw a line from P1 to P2.

P1 =(5,7) ; P2 =(10, 180º)

P3 =(-4,2) ; P4 =(5, 45º)

Grid reference

P1 =(5,7) P2 =(10, 180º)

P3 =(-4,2) P4 =(5, 45º)

2.1 Basic Graphic Knoledge

Relative coordinates mark the last point used as the new grid reference from where we mark the next.

Grid reference

P1 =(5,7)

P2 =(@-9,-5)

2.1 Basic Graphic Knoledge

Exercise: Using your notebook grid mark this points:

0,10

@10,0

@20,20

@-20,0

@10,20

@10

(X,Y)

2.1 Basic Graphic Knoledge

Exercise: Using your notebook grid mark this points:

0,10

@10,0

@20,20

@-20,0

@10,20

@10

(X,Y)

2.2 Relativa, Absolute and polar cordinates

Exercise: Using Qcad mark this points:

0,10

10,10

10,30

20,50

30,30

30, 10

(40,10)

(40,0)

(X,Y)

2.2 Relativa, Absolute and polar cordinates

Exercise: Using Qcad mark this points:

0,10

@10,0

@20,20

@-20,0

@10,20

@10

(X,Y)

2.2 Relative, Absolute and Polar coordinates

Welcome to Qcad

2.2 Relative, Absolute and Polar coordinates

We can use Qcad to draw points clicking onThen we have to decide what type of

coordinate we are using:Absolute: and write the (x,y) belowRelative: and write the (x,y) belowPolar: complete the gaps

2.2 Relativa, Absolute and polar cordinates

Exercise: Using Qcad mark this points:

0,10

10,10

10,30

20,50

30,30

30, 10

(40,10)

(40,0)

(X,Y)

2.1 Basic Graphic Knoledge

Exercise: draw these points.

P1 =(5,70º)

P2 =(10, 180º)

P3 =(-4,20º)

P4 =(5, -45º)

Grid reference

2.2 Relativa, Absolute and polar cordinates

Exercise: Using Qcad mark this points:

0,10

@10,0

@20,20

@-20,0

@10,20

@10

(X,Y)

2.3 Lines, Squares, Circules

Exercise using absolute coordinates draw this views

2.3 Lines, Squares, Circules

Marking: Mark, using parallel marking these objects.

2.4 Views of an object

• Draw this object using Qcad.

2.5 Marking

Marking: Mark, using parallel marking these objects.

2.6 Perspective

Regular objects are drawn using the caballera perspective

All lines are parallel to Z, X or

Y axes

2.6 Perspective

Caballera: X and Y axes form a 90º angle and Z axe form a 135º angle

Z axe

Y axe

X axe

90º

90º

135º

2.6 Perspective systemsIn X and Y axes measures are applied directly. But, in order to create a human vision of the object, Z axe form a 135º angle and measures have a ½ reduction

½ reduction in all z measures

10 10 10