1. Alternate Views Introduction to Engineering Design
© 2012 Project Lead The Way, Inc.

2. Presentation Name
Course Name
Unit # – Lesson #.# – Lesson Name
Alternate Views
In some cases, orthogonal projections and pictorials are not sufficient to specify all the details of a part.
Section View. Used to show “inside” details not apparent on the exterior of the part
Auxiliary View. Used to show features that are located on an inclined surface in true size and shape
Detail View. Used to show a “close-up” view of features that are too small to adequately specify in another view

3. Orthographic Projections (multiviews)
The outside of an object can be shown fully with an Orthographic view. Front, right, top view etc.

4. Hidden lines
However the INSIDE of an object CANT be shown very well with an orthographic projection.
Hidden lines will be mixing with other hidden lines and object line
Plus you can’t dimension to hidden lines
How do you dimension the inside?

5. Cut the object!

6. Before and after cut

7. Section View Provides a view of an object as if it were cut by a saw
So you can have a clear view of the inside of an object
Only used when detail can’t be seen from the outside

8. Cutting plane line Indicates location of the cut Thick and broken line
Big dash, two small dashes big dash two small dashes…
Arrows indicate direction of view
Labeled with a letter for identification on drawing B B
Cutting plane line

9. Section Lines Thin lines usually drawn at a 45 degree angle
Indicates the material that has been cut through in a sectional view
Empty space has no section lines
Hidden lines that were cut through are now object lines

10. Section View Types Full Section View Half Section View
Offset Section View

11. Full Section View Cutting plane line passes fully through the part
Presentation Name
Course Name
Unit # – Lesson #.# – Lesson Name
Full Section View
Cutting plane line passes fully through the part
The cutting plane line is a straight line
The piece being viewed is the piece with the arrows pointing to it, the other piece is disregarded
Doesn’t have to cut exactly in half

12. Full Section Example
Section lines indicate material that is cut by the cutting plane line
Imagine the part is cut at cutting plane line
Direction of View
This half of the part is removed

13. Full Section Example
Section lines indicate material that is cut by the cutting plane line
Imagine the part is cut at cutting plane line
Direction of View
This half of the part is removed

14. Half Section View
Used on symmetrical parts to show inside as well as outside details in one view
One quarter of the part is cut away
Cutting plane line goes halfway through the part (to the center of the part
Used a lot with parts with axis of rotation (when revolve is used

15. Half Section Example Half Section
Only one arrowhead in the direction of view
Note that the cutting plane line cuts away a quarter of the part
Half Section

16. Offset Section Used when several features of an object do not line up
Have one offset section view instead of multiple full section views
Note how the cutting plane line changes direction and follows the center of each feature

18. Presentation Name
Course Name
Unit # – Lesson #.# – Lesson Name
With a tape measure, how would you tell a person the dimensions of the center of the hole?
28 inches from edge on the bottom of board to the center of the hole in a straight line
14 inches vertically from the bottom of the board. Then horizontal until you hit the board

19. Auxiliary Views
Presentation Name
Course Name
Unit # – Lesson #.# – Lesson Name
Orthographic projection of an inclined plane (angled surface) which appears foreshortened in a principle orthographic projection
Used to show the true size and shape of an inclined plane and the features on it
Line of sight is perpendicular with the inclined surface. Looking at the inclined surface straight on.

20. Auxiliary Views
The circle on the inclined surface on the top add right view look like ellipses but in the auxiliary view it is a circle
The inclined surface looks shorter on the top and right view than on the auxiliary view. You see the true size on the auxiliary view.
The location of the hole on the inclined surface can not be determined on the top or right view but it can be on the auxiliary view.
Dimension the inclined surface on the auxiliary view

21. Foreshortened
Foreshortened surfaces do not give a clear or accurate representation of the size or shape of the surface or features and should not be dimensioned
foreshortened face
TOP
FRONT
RIGHT SIDE

22. Auxiliary Views -summary
Presentation Name
Course Name
Unit # – Lesson #.# – Lesson Name
Auxiliary Views -summary
An auxiliary view allows the viewer to look perpendicular to an angled surface to witness the true size and shape of that surface and its features (a hole in this example).
True Height
Auxiliary Distance
TOP
We will not use auxiliary views in this unit, but they will be presented in more detail in Unit 8.
FRONT
RIGHT SIDE

23. Detail Views
An enlargement of a portion of another view to illustrate small features on a part
Not to be confused with a Detail Drawing which is any drawing that contains all the information needed to manufacture a part

24. Detail View Example
A feature is broken out and enlarged for clarity