AutoCAD Tutorial V: Introduction to Orthographic Projection

You will draw the front, top, and right side views of the following object.

Procedure:

  1. Make a new drawing. Set up the:
    Units: Use English, Use Decimal inches with a Precision of 0.00
    Drawing Limits: Use (0,0) to (12.00, 9.00)
    Drafting Setting: You may want to have a 1” grid, 0.1” snap (Optional)
  2. Zoom—All.
  3. Make the following layers: Visible and Construction.
  4. In your visible layer, draw the visible lines of the front view.
  5. Draw a rectangle using the following commands.
  6. Command: Line
  7. Line Specify first point: Type 0,0.
  8. Specify next point or [Undo]: @3<0
  9. Specify next point or [Undo]: @2<90
  10. Specify next point or [Undo]: @3<180
  11. Specify next point or [Undo]: @2<-90
  12. Specify next point or [Undo]: Enter
  13. Draw a line from 0,1.1 to @1<0
  14. Draw a line from 3,1.1 to @-1<0
  15. Draw a circle with center point 1.5,0.5 and radius 0.25

Note: Some visible features are missing, but this is all we can do for now.

  1. In the construction layer, draw horizontal and vertical projectors off of every feature in the front view. (Hint: To draw perfectly straight horizontal and vertical lines turn the ORTHO on. This restricts lines to be drawn at angles of 0o or 90o only. The ORTHO can be turned on by clicking the icon near the bottom of the screen.) The length of these lines in not important, just very long.

Note: If the computer is snapping to the wrong geometric feature, turn off your OSNAP (object snap).

  1. In the visible layer, draw the visible features in the right side view. (see figure on the next page.)
  2. Draw the L shape using the following commands.
  3. Command: Line
  4. Line Specify first point: Near
  5. to Click your left mouse button near the bottom horizontal construction line (projector).
  6. Specify next point or [Undo]: @2<0
  7. Specify next point or [Undo]: per
  8. to Click on the top horizontal construction line.
  9. Specify next point or [Undo]: @0.5<180
  10. Specify next point or [Undo]: per
  11. to Click on the horizontal construction line just below the top one.
  12. Specify next point or [Undo]: @1.5<180
  13. Specify next point or [Undo]: per
  14. to Click on the bottom horizontal construction line.
  15. Specify next point or [Undo]: Enter

  1. Draw the angled feature using the following commands.
  2. Command: Line
  3. Line Specify first point: int
  4. to Click your left mouse button near the upper left corner of the L shape.
  5. Specify next point or [Undo]: @2<195
  6. Specify next point or [Undo]: Enter
  7. Command: Line
  8. Specify next point or [Undo]: int
  9. to Click on the upper left corner of the base of the L shape.
  10. Specify next point or [Undo]: per
  11. to Click on the top horizontal construction line.
  12. Specify next point or [Undo]: Enter
  13. Trim off the excess lines.

  1. In the hidden layer, draw the hidden lines for the hole in the right side view. (Hint: Use the object snap command INT to snap to where the horizontal construction lines intersect the vertical visible lines.)

  1. In the construction layer, project back from the right side view to the front view.
  2. In the visible layer, draw the missing visible lines in the front view using the appropriate object snap commands.

  1. In the construction layer, draw the projectors need to complete the top view. (see figure on the next page.)
  2. Draw a 45o projector off the upper right corner of the front view using the following commands.
  3. Command: Line
  4. Line Specify first point: int
  5. to Click your left mouse button near the upper right corner of the front view.
  6. Specify next point or [Undo]: @7<45
  7. Specify next point or [Undo]: Enter
  8. Draw vertical projector up from the right side view and horizontal projectors over to the top view. (Hint: Turn the ORTHO on.)
  1. Using similar techniques, draw the visible and hidden features of the top view.
  1. In the center layer, draw the centerlines in the front view using the following steps.
  2. Draw a circle around the circle in the front view that is slightly larger. The two circles should have the same center point.
  3. Draw a horizontal line from the left quadrant of the new circle to the right quadrant.
  4. Draw a vertical line in a similar way.
  5. Erase the new circle that was drawn.

Note: If your centerlines do not break, try a smaller LTSCALE. I suggest a value of 0.4.

  1. Draw the centerlines in the right side and top views using the following steps.
  2. Turn the ORTHO on.
  3. Draw a line from the end point of the horizontal centerline in the front view to perpendicular to the back visible line of the right side view.
  1. Trim this centerline using the front visible line of the right side view as your cutting edge.
  1. Click on the centerline that was just drawn. Notice the blue boxes that appear.
  2. Click on the right blue box and move about 0.25 inches to the left.
  3. Click on the left blue box and move about 0.25 inches to the right.

Note: When extending your centerlines, there is no need to be completely accurate. We just want them to look good. This means that the dashes should be approximately centered.

  1. Follow the same steps to create the centerline in the top view.
  1. Prepare to print the object to scale. You need to print two versions of this assignment. One version should have only the visible layer. The second version should have all layers shown. Refer to the previous manuals on how to print to scale with a title block. Use a custom scale of 1”=1” (1.000) if it will fit. Otherwise use a scale of 1”=2” (0.500). Staple the drawings together.

(Potential Problem: Is it really printed to scale? Cure: Use a ruler to measure the bottom of the front view to confirm its length. If it was drawn 3 inches long in AutoCAD then it should be EXACTLY 3 or 1.5 inches long if you printed at 1"=1” or 1"=2" scale, respectively.)

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