1 coordinate systems john kirby. 2 coordinate systems in autocad wcs or world coordinate system –...
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1
Coordinate Systems
John Kirby
2
Coordinate Systems in AutoCAD
• WCS or World Coordinate System– Referred to as the top right quadrant (quadrant 1) of
the Cartesian Coordinates System– Used when inputting lines with mouse– Default system for inputting lines
• UCS or User Coordinate System– User defined– Points are typed to locate position by Absolute,
Relative, or Polar input points
3
2D Cartesian Coordinate System
2 4 6 8-2-4-6-8
2
4
6
8
-2
-4
-6
-8
Y Axis
X Axis-X Axis
-Y Axis
Quadrant 1
Quadrant 2
Quadrant 3
Quadrant 4
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Define Absolute Position
• Based on X & Y axes intersection• 0 for X• 0 for Y
2 4 6 8-2-4-6-8
2
4
6
8
-2
-4
-6
-8
Y Axis
X Axis
-X Axis
-Y Axis
5
What is the absolute position?
2 4 6 8-2-4-6-8
2
4
6
8
-2
-4
-6
-8
Y Axis
X Axis-X Axis
-Y Axis
5,5
6
What is the second absolute position?
2 4 6 8-2-4-6-8
2
4
6
8
-2
-4
-6
-8
Y Axis
X Axis-X Axis
-Y Axis
5,5-5,-5
7
What is the third absolute position?
2 4 6 8-2-4-6-8
2
4
6
8
-2
-4
-6
-8
Y Axis
X Axis-X Axis
-Y Axis
5,5-5,5
-5,-5
8
What is the fourth absolute position?
2 4 6 8-2-4-6-8
2
4
6
8
-2
-4
-6
-8
Y Axis
X Axis-X Axis
-Y Axis
5,5-5,5
-5,-5 5,-5
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What size is the object if you connect the four points?
2 4 6 8-2-4-6-8
2
4
6
8
-2
-4
-6
-8
Y Axis
X Axis-X Axis
-Y Axis
5,5-5,5
-5,-5 5,-5
10 units by 10 units
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Draw the same 10 X 10 box using AutoCad
Type line at the command prompt in AutoCAD and press enter
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Input the First Absolute Point
Type 5,5 to specify the first point and press enter.
You have now input the first point in Quadrant 1 to the absolute position of 5 in the X and 5 in the Y position.
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Input the Second Absolute Point
Type -5,5 to specify the next point and press enter.
You have now input the second point in Quadrant 2 to the absolute position of -5 in the -X and 5 in the Y position.
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Input the Third Absolute Point
Type -5,-5 to specify the next point and press enter.
You have now input the third point in Quadrant 3 to the absolute position of -5 in the -X and -5 in the -Y position.
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Input the Fourth Absolute Point
Type 5,-5 to specify the next point and press enter.
You have now input the fourth point in Quadrant 4 to the absolute position of 5 in the X and -5 in the -Y position.
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Completing the 10 x 10 Square
Type c and press enter. This will close the square.
This will close the square to 10 x 10 units when you press the enter key.
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The Completed 10 x 10 Square • This will closed 10 x 10 square. • Press the f2 key and the text window will open that displays all of
the absolute points and commands used in this activity.
AutoCAD text window will open.
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Thinking for Yourself
• Using only Quadrant 1• Draw the initials for your first and last name• Plot the initials using graph paper to layout• Complete the assignment using a CAD
program to draw the absolute points for your initials
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Plot all Points in Quadrant 1
2 4 6 8
6
8
Y Axis
X Axis
2
4
10 12 14 16
10
12
0
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Plot all Points in Quadrant 1
2 4 6 8
6
8
Y Axis
X Axis
2
4
10 12 14 16
10
12
0