Co-ordinate systems

Hello Friends,

            This is my first blog on AutoCAD tutorials. I won’t waste time on overview of AutoCAD and its uses which everyone knows. I will start directly with Co-ordinate systems of AutoCAD.

            Co-ordinates systems are not of more use left in recent versions but still knowledge of co-ordinate systems is important as this keeps your mind sharp. 

ABOUT CO-ORDINATE SYSTEM:

    If you want to make any object in autocad you have two options. 

1. you can directly click at any know point or 

2. you can specify co ordinates of the point in command box.

CARTESIAN AND POLAR CO-ORDINATE SYSTEM:

Cartesian co ordinate system works only on linear distance. it have 3 axis X,Y,Z. when u specify any point with (+ or -) sign it prompts autocad to move along positive axis or negative axis at a specified distance.

while working in 2D drafting, we have only 1 plane XY plane which is also known as work plane. X co-ordinate resembles horizontal distance and Y co-ordinates resemble vertical distance.

Polar co-ordinate sytems works with angle as well. in polar co ordinate system only length is specified followed with its angle. 

cartesian co-co ordinate system and polar co-ordinate system, both uses absolute co-ordinate and relative co-ordinates.

Third way of making any lines is to directly specify its distance which is also know as direct distance entry

Units which can be used for linear units are decimal, integer, scientific, architectural, fractional units. And units which can be used with angular measurements are degree, grads, radians, surveyor's unit.

To set any unit system you can use UNITS command.

Note:

• co-ordinate system works purely on units this does'nt represent 1mm or 1 meter. you have to set units as soon as you open your drawing file.

 

Absolute Co-ordinate system: Rectangle of size 5x3 having basepoint as point P1 at co ordinate 3,3  

Use absolute coordinates when you know the precise X and Y values of the point.                                                                

Syntax: - #X co-ordinate, y co-ordinate never use # for specifying 1st point.         

Reference: Always origin. i.e. UCS origin (0,0)                                                                       

P1= 3, 3

P2= #8, 3

P3= #8, 6

P4= #3, 6

 

 

 

Relative Rectangular Co-ordinate system: Draw Rectangle of size 12x26.          

Use relative coordinates when you know the location of a point in relation to the previous point.                          

Syntax: - @X displacement, y displacement,

Reference: Previous point.                                                                                                  

P2= @12, 0

P3= @0, 26

P4= @-12, 0

P1= @0,-26                                                                                 

 

 

Relative Polar Co-ordinate system:  Draw Equilateral triangle of side 30.                                       

Syntax: - @X displacement < Angle

Reference: Previous point.                                                                                                  

P1= @30<0

P2= @30<120

P3= @30<240

Video for the above tutorial: 

Absolute Co-ordinate systems: https://youtu.be/i5jmfvDFqcM

Relative rectangular Co-ordinate system: https://youtu.be/zGlPaLAcixI

Relative Polar Co-ordinate system: https://youtu.be/L96i_OUt0Yk

                                                                                                                       

Related Concepts:

1. About Polyline.
2. About lines.
3. About multilines.

Relates Task:

1. How to draw lines.
2. How to draw polylines.
3. How to draw multiline.
4. How to edit multiline.
5. How to create multiline style.

Related reference:

1. Commands for linear geometric objects.
2. From command.
3. Mid point command.
4. Direct distance entry.
5. How to draw lines with precision.