Coordinate Systems John Kirby 1 Coordinate Systems in
Coordinate Systems John Kirby 1
Coordinate Systems in Auto. CAD • 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 2
2 D Cartesian Coordinate System Y Axis 8 6 Quadrant 2 Quadrant 1 4 2 -X Axis -8 -6 -4 -2 2 -2 4 6 8 -4 Quadrant 3 -6 Quadrant 4 -8 -Y Axis 3
Define Absolute Position • Based on X & Y axes intersection Y Axis 8 • 0 for X 6 • 0 for Y 4 2 -X Axis -8 -6 -4 -2 -2 2 4 6 8 X Axis -4 -6 -8 -Y Axis 4
What is the absolute position? Y Axis 8 5, 5 6 4 2 -X Axis -8 -6 -4 -2 2 -2 4 6 8 -4 -6 -8 -Y Axis 5
What is the second absolute position? Y Axis 8 -5, -5 5, 5 6 4 2 -X Axis -8 -6 -4 -2 2 -2 4 6 8 -4 -6 -8 -Y Axis 6
What is the third absolute position? Y Axis 8 -5, 5 6 4 2 -X Axis -8 -6 -5, -5 -4 -2 2 -2 4 6 8 -4 -6 -8 -Y Axis 7
What is the fourth absolute position? Y Axis 8 -5, 5 6 4 2 -X Axis -8 -6 -5, -5 -4 -2 2 -2 -4 4 6 8 5, -5 -6 -8 -Y Axis 8
What size is the object if you connect the four points? 10 units by 10 units Y Axis 8 -5, 5 6 4 2 -X Axis -8 -6 -5, -5 -4 -2 2 -2 -4 4 6 8 5, -5 -6 -8 -Y Axis 9
Draw the same 10 X 10 box using Auto. Cad Type line at the command prompt in Auto. CAD and press enter 10
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. 11
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. 12
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. 13
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. 14
Completing the 10 x 10 Square Type c and press enter. This will close the square to 10 x 10 units when you press the enter key. 15
The Completed 10 x 10 Square • This will closed 10 x 10 square. • Press the f 2 key and the text window will open that displays all of the absolute points and commands used in this activity. Auto. CAD text window will open. 16
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 17
Plot all Points in Quadrant 1 Y Axis 12 10 8 6 4 2 0 2 4 6 8 10 12 14 16 X Axis 18
Plot all Points in Quadrant 1 Y Axis 12 10 8 6 4 2 0 2 4 6 8 10 12 14 16 X Axis 19
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