1. Thursday, October 28th 2004
ENGR
Sectioned Views

2. Learning Objectives
List and recognize by name; symbol; and ANSI number these materials:
- Cast Iron Aluminum Brass, Bronze,
- Steel Zinc or Copper
Identify a drawing as being a:
- Full Section Offset Section Revolved Section
- Half Section Broken-Out Section - Removed Section
Given an orthographic view; draw section views:
- In Pencil or In AutoCAD
Use revolutions and partial views (as conventional practices) to construct sectional views of an object.
List the parts of a drawing which do not get crosshatched, even if the cutting plane passes through them.
Sketch a cutting plane for any of the sections listed above

3. Readiness Assessment Test 9.2.1
Individually answer the following questions. You will be given 2 minutes:

4. Readiness Assessment Test 9.2.1
Individually answer the following questions. You will be given 2 minutes:
List 4 types of sectional views.

5. Team Discussion Item As a team, discussing the following question:
What is the purpose of sectional views?

6. Purpose of Sections Show internal detail
Replace complex orthographic views
Describe materials in an assembly
Depict assembly of parts

7. Sectioning Practices Different parts at different angles
Hatch spacing of about 1/16”-1/8”
Cutting plane line .020” wide (bold)
Section or hatch lines -- thin .007”
Visible lines -- wide .015”
Not parallel or perpendicular to boundary

8. Sectioning Practices
When sectioning an assembly of several parts, draw section lines at varying angles to distinguish separate parts.

9. Most common ANSI Material Patterns
ANSI No Name Pattern
ANSI Cast Iron, General
ANSI Steel
ANSI Brass, Bronze, Copper
ANSI Magnesium, Aluminum
Earth

10. What is ANSI? .

11. Available Hatch Patterns in AutoCAD

12. Cutting Plane
CUTTING PLANE LINE
The sight arrows at the end of the cutting plane are always perpendicular to the cutting plane.
Line thickness of the cutting plane is the same as the visible object line.
The direction of the arrow indicates the line of sight.

13. Types of Sections……..Fig #:
Broken-out section……………6.3
Conventional breaks………….6.4
Full section……………………..6.5
Half section……………………..6.8
Revolved section……………..6.10
Removed section……………..6.11
Offset section………………
(See Essentials of Engineering Design Graphics by Vinson for figure references)

14. Full Section Cutting plane passes through entire object
Hidden lines are omitted
Visible lines “behind” the cutting plane must be shown

15. Individual Exercise (7 min) ● Sketch a full section of the object shown below

16. Individual Exercise (7 min) ● Were you correct
Individual Exercise (7 min) ● Were you correct ? ● What material (hatch pattern) did you use?

17. Half section: A quarter of assembly removed
CUTTING PLANE LINE
A quarter of assembly removed
Half of view is cross-hatched
ALL hidden lines may be omitted
Center line divides halves
Center line remains only if associated feature is sectioned

18. Offset section: Bend the cutting plane to show more features
CUTTING PLANE LINE
Bend the cutting plane to show more features

19. Offset section: Sectional view does not denote location of offset
CUTTING PLANE LINE
Sectional view does not denote location of offset

20. Revolved section: Show cross- sections by rotating sections 90o
The section view stays on the object.

21. Removed section:
Removed sections are offset from the object.

22. Broken out section: Used to section a small portion of the object
Does not modify the rest of the view

23. Conventional Practices
Conventional practices are accepted drawing techniques that violate the rules of orthographic projection
They are designed to simplify orthographic drawing of complex features.

24. Aligned Parts:
Arms
Lugs

25. Aligned Parts:
Ribs & Holes
Single Arm

26. Parts Not Sectioned.
Don’t crosshatch (even though the cutting plane may pass thru them):
Ribs, webs, spokes
Thin parts like gaskets
Ball bearings, roller bearings
Most vendor items:
 Bolts  Washers  Shafts
 Nuts  Screws  Pins

27. Partial Views Use partial views to conserve space
Which half depends on whether you section the view or not.

28. Conventional breaks: …….For extremely large parts

29. Crosshatching in AutoCAD
AutoCAD can apply a given pattern to fill an area
The area must be a closed area
To fill the area use the BHATCH command.

30. Pair Homework Assignment
Drawings (in AutoCAD):
28 all
29 all
32 a, b, c
34 all
Due: Beginning of class 10.2

31. Stop