1. Multi-view Drawing
Gamal Prather

2. Multi-view Drawings
Pictorial sketches are great for engineers to explain ideas and communicate what the final part will look like to the customer.
Unfortunately, pictorial drawings have some disadvantages.
Foreshortened views and distorted features do not allow for accurate prototyping.
Many times, for parts to be accurately depicted, you need straight on views of each surface.

3. Orthographic Drawings
These straight-on views are called ORTHOGRAPHIC PROJECTIONS
aka MULTIVIEW DRAWINGS
These views are perpendicular to a line of sight
There are 6 of these views to any object

4. Orthographic Drawing The arrows represent the line of sight associated
with each view.
View the Orthographic
Drawings for this object

5. Orthographic Principal Views
Front,
Top and Right views
are used most often. You can
see how other views resemble
these three except they are not
as clear due to hidden lines.
Note how the views
are oriented. Each view is
adjacent to the other as
if they were unfolded
from a 3D shape.
ISO

6. Orthographic Angle of Projection
The example you have just seen is shown in THIRD ANGLE projection
This is the standard in the United States and Canada
The rest of the world draws in FIRST ANGLE projection

7. Orthographic Spatial Quadrants and Planes
This sketch shows the
quadrants where the angles
of projection are made from
In 3rd angle projection,
the projection planes used
to create views are
as shown in red.
Top
Front
Right Side

8. Orthographic 3rd Angle Projection
Views are projected onto planes
that exist on the face of that view.
Arrows show the direction of the
projection
ISO Symbol

9. Orthographic Spatial Quadrants and Planes
In 1st angle projection
the projection planes used to
create the views are
as shown in red.
Top
Front
Side

10. Orthographic 1st Angle Projection
Views are projected onto planes
that exist on the opposite face of the
view you want to display. The
arrows show the direction
of the projection.
ISO Symbol

11. View Selection Finding the best view of a part can be tricky
Two or more sides may look like the best solution for a front view.
On the next slide is a list of characteristics that you should use in choosing your views.

12. View Selection Criteria
The front view should show the ...
Shows best shape and characteristic contours
Longest dimensions
Fewest hidden lines
Most stable and natural position

13. View Selection No hidden lines in any views Most natural position
for isometric view
Best shape
description
Longest
Dimension

14. Selecting Number of Views
How many views do you need?
Usually not more than 3, but you may only need one or two.

15. One View Selection Two views Uniform shape. will be identical
All dimensions easily
shown on one view

16. One View Selection It is also possible to have one view drawings
of objects that are flat
and have even thickness.
Gauges and gaskets are
two such objects. We
have a gauge here on the
left.

17. Two View Selection Symmetrical parts. A third view
would be identical to the other
views
Second view is necessary for
depth.

18. Line Precedence
Different line types frequently must be drawn in the same space
LINE PRECEDENCE helps us decide which lines to draw
Generally you should draw …
Object lines over hidden lines and centerlines
Hidden lines over centerlines
Cutting plane lines over centerlines

19. Precedence of Lines An object line here takes precedence
over the center line. However we
draw short thin lines beyond the
object to show there is a center line
underneath the object line.

20. Precedence of Lines Object lines took precedence over
the hidden lines you would see
from the hole. The center line in
the top view would show the depth
of the hole as well as the right
side view.

21. References
Madsen, David A., Shumaker, Terence M., Stark, Catherine, Turpin, J. Lee, Engineering Drawing and Design Second Edition,Delmar Publishers, 1996, ISBN
Brown, David, You Can Draw, North Light Books, Cincinnati, Ohio, 1986, ISBN
Olivo, Dr. C. Thomas, Olivo, Thomas P., Basic Blueprint Reading and Sketching Sixth Edition, Delmar Publishers Inc., 1993, ISBN
Johnson, Cindy M., Lockhart, Shawna D., Engineering Design Communication, Prentice Hall, 2000, ISBN
Spencer, Henry Cecil, Dygdon, John Thomas, Novak, James E; Basic Technical Drawing 6th Edition; Glencoe McGraw Hill; New York, New York,1995, ISBN

22. Do you want to be a good sketcher?
Practice
First Slide