1. Multiview Sketching Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Multiview Sketching
Introduction to Engineering Design
© 2012 Project Lead The Way, Inc.
Project Lead The Way, Inc.
Copyright 2007

2. Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
2D view of a 3D shape
There are always six principal 2D views of a 3D object
Front, back, top, bottom, left and right
Left view
Project Lead The Way, Inc.
Copyright 2007

3. Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Multiview Drawings (Orthographic Drawings or Orthographic Projection Drawings)
Shows two or more two-dimensional views of a three-dimensional object.
Provides 2D shape drawing of an object.
When combined other with dimensions, the drawings serve as the main form of communication between designers and manufacturers.
Blueprints
Ortho means straight; rectangular; upright.
Project Lead The Way, Inc.
Copyright 2007

4. Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
The six principal views of orthographic Projection drawings (Multiview drawings or orthographic drawing)
Project Lead The Way, Inc.
Copyright 2007

5. Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
The six principal views of orthographic Projection drawings (Multiview drawings) or orthographic drawing
Project Lead The Way, Inc.
Copyright 2007

6. Orthographic Projection
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Orthographic Projection
Orthographic Projection is the easiest technique used to create multiview drawings.
Orthographic Projection is the projection of the features of an object onto an imaginary plane.
Plane is a flat surface that goes on forever but has no depth
The projection of the features from the object to the plane is made by lines of sight that are perpendicular to the imaginary plane.
Perpendicular meets at 90 degree angles
Project Lead The Way, Inc.
Copyright 2007

7. Orthographic Projection (Glass Box Method)
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Orthographic Projection (Glass Box Method)
The best way to understand orthographic projection (glass box method) is to imagine an object contained inside a glass box.
Project Lead The Way, Inc.
Copyright 2007

8. Orthographic Projection (Glass Box Method)
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Orthographic Projection (Glass Box Method)
There is a total of six glass walls surrounding the object. Each wall represents a projection plane onto which a two- dimensional object view will be created.
Project Lead The Way, Inc.
Copyright 2007

9. Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Projection Plane
Also referred to as a plane of projection or picture plane, is an imaginary surface that exists between the viewer and the object.
The projection plane is the surface onto which a two-dimensional view of a three-dimensional object is projected and created.
Project Lead The Way, Inc.
Copyright 2007

10. Orthographic Projection
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Orthographic Projection
Start by focusing only on the front projection plane.
A person standing in front of the object would see only the five corners identified in black. 2 3 1 4
line of sight
at 90° angle to projection plane 5
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Copyright 2007

11. Orthographic Projection
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Orthographic Projection
Projection lines are used to project each corner outward until they reach the projection plane.
Project Lead The Way, Inc.
Copyright 2007

12. Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Projection Line
An imaginary line that is used to locate or project the corners, edges, and features of a three-dimensional object onto an imaginary two-dimensional surface.
Project Lead The Way, Inc.
Copyright 2007

13. Orthographic Projection
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Orthographic Projection
The visible edges of the object are then identified on the projection plane by connecting the projected corners with object lines.
Project Lead The Way, Inc.
Copyright 2007

15. Orthographic View Selection
Recommendations for how to select the front view
Most natural position or use
Shows best shape and characteristic contours
Longest dimensions
Fewest hidden lines
Most stable and natural position

16. Orthographic View Selection
Best shape
description
No hidden edges
Longest dimension
Most natural position
BEST FRONT VIEW

17. Orthographic Projection Visually Explained
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Orthographic Projection Visually Explained
Project Lead The Way, Inc.
Copyright 2007

18. STOP HERE

19. Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Multiview Drawing
All three-dimensional objects have width, height, and depth.
Width is associated with an object’s side-to-side dimension.
Height is associated with an object’s top-to-bottom dimension.
Depth is associated with an object’s front-to-back dimension.
Project Lead The Way, Inc.
Copyright 2007

20. Multiview Drawing TOP VIEW FRONT VIEW RIGHT-SIDE VIEW
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Multiview Drawing
TOP VIEW
FRONT VIEW
RIGHT-SIDE VIEW
Project Lead The Way, Inc.
Copyright 2007

21. Multiview Drawing 45° Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Multiview Drawing
45°
Project Lead The Way, Inc.
Copyright 2007

22. Sketching a Multiview Drawing
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Sketching a Multiview Drawing
Given the overall dimensions of the object, a pencil, and a sheet of graph paper, sketching a multiview drawing can be easily done using points, construction lines, and object lines.
Project Lead The Way, Inc.
Copyright 2007

23. Sketching a Multiview Drawing
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Sketching a Multiview Drawing
Step 1 – Layout the boxes within which the individual views will occur using points and construction lines.
TOP
FRONT
RIGHT SIDE
Project Lead The Way, Inc.
Copyright 2007

24. Sketching a Multiview Drawing
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Sketching a Multiview Drawing
Step 2 – Use construction lines between the views to indicate the geometry of the views.
Project Lead The Way, Inc.
Copyright 2007

25. Sketching a Multiview Drawing
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Sketching a Multiview Drawing
Step 3 – Identify the visible edges with object lines.
Project Lead The Way, Inc.
Copyright 2007

26. Sketching a Multiview Drawing
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Sketching a Multiview Drawing
Step 4 – Locate hidden lines.
Project Lead The Way, Inc.
Copyright 2007

27. STOP

28. Orthographic Projection
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Orthographic Projection
Orthographic projection drawing have six principal view. But in most case three or less are needed.
Project Lead The Way, Inc.
Copyright 2007

29. Number of views needed Orthographic Projection
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
Number of views needed Orthographic Projection
6 views are rarely needed.
Want the least views necessary to show the details of the object
Want the least views necessary to dimension the drawing
Don’t dimension to hidden lines, in that case add another view.
The less views the better but if you really need another view to get a good feel of what the object is you can
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Copyright 2007

30. All six views are not always needed
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
All six views are not always needed
LEFT SIDE
RIGHT SIDE
FRONT
All 6 views are normally not needed. Here is only 4 views but the right and left are mirror images. So we can get rid of the left.
Note that hidden lines are not shown for simplicity.
Do you think the view chosen for the Front View is the best choice? Why or why not?
Left view is not needed. It is a reflection of the right view. So engineers don’t want extra drawings. Just the bare minimum
Remember the recommendations for how to choose a front view:
Most natural position or use
Shows best shape and characteristic contours
Longest dimensions
Fewest hidden lines
Most stable and natural position
An argument can be made for using what would be the Left Side view <click> for the Front View in that it shows the characteristic shape of the chair, but the Front View shown in the slide provides a better view of the decorative wood work on the back of the chair. Either view would suffice as a front view.
Dining Chair
Project Lead The Way, Inc.
Copyright 2007

31. A cylinder only really needs one view. But it can be done with two.
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
A cylinder only really needs one view. But it can be done with two.
5.0
4.0
4.0
5.0
Two view
One view
Project Lead The Way, Inc.
Copyright 2007

32. Number of Orthographic Projections
One View is needed
Some cylindrical shapes
Uniform thickness or shape
two views would be identical
All dimensions properly and easily shown on one view
depth

33. Number of Orthographic Projections
Two Views
Symmetrical part
Second view is necessary for depth since all depth is not constant
A third view would be identical to another one
All detail and dimensions fit on two

34. 2 views are minimum but three show the details are better
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
2 views are minimum but three show the details are better
Project Lead The Way, Inc.
Copyright 2007

35. 3 views are needed Historical example: Leonard P. Karr (1913–1995)
What is this object?
Do you think Mr. Karr aligned his drawing correctly?

36. Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
A Question…
Each of the blocks at the right has the same overall dimensions and color. What else do they have in common?
Project Lead The Way, Inc.
Copyright 2007

37. They all have identical top views!
Multiview Sketching
Introduction to Engineering Design
Unit 2 Technical Sketching and Drawing
A Question…
They all have identical top views!
Project Lead The Way, Inc.
Copyright 2007