1. Chapter 20 Working Drawings
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2. Components of Engineered Product Sketches- document initial design solutions Models- represent the final design solutions Drawings- deliverables for production Production/ Working Drawings Information required to make the part or assembly of a design

3. How much does it cost to make a design change?
Models and drawings are used as _______tools, to manufacture products, and show how complex assemblies are put together.
How much does it cost to make a design change?

4. Complete Set of Working Drawing Objectives
Completely describe parts visually and dimensionally
Show parts in assembly
Identify all parts
Specify standard parts
How do we accomplish these objectives?
________________ Drawings
____ __________ Drawings

5. Assembly Drawings A title block
Drawing showing all the standard and non-standard parts
A bill of Materials (BOM)

6. Sub-Assembly Drawings
A title block
Drawing showing all the standard and non-standard parts
A bill of Materials (BOM)

7. Detail Drawings A title block
Fully defined part (dimensioned and toleranced)
GD&T
Manufacturing information
Weld Symbols
Surface Texture
Process
Material

8. Standard Parts
Not detailed but shown in assembly (Fasteners, bushings, bearings etc.)

9. 4 Major Parts of assembly drawings
All parts drawn in operating position
Parts list (BOM) showing:
Leader lines w/ balloons assigning detail #’s
Machining & assembly operations w/ critical dimensions related to these functions

10. Communicate how part interrelate
Assemblies
Communicate how part interrelate
Exploded vs. Sectioned

11. Rules for Assembly drawings:
Minimum # of views to describe assembly
Dimensions not shown unless necessary to provide overall assembly dimensions or assist in machining operations necessary for assembly (field weld)
Hidden lines omitted except when needed for assembly or clarity
Phantom lines show movement or assembly movements

12. Types of Assembly drawings:
Outline Assembly- exterior shape
Sectioned- interior shape
Pictorial- Isometric view

13. Used to record ALL general information necessary for working drawings
Title Blocks:
Used to record ALL general information necessary for working drawings
Name and Address of Company
Title of Drawing
Drawing #
Names and Dates of designer, checker, issue date, contract # etc.
Design approval, when subcontractors are used
Additional approval block
Predominant drawing scale
J. Drawing Sheet size letter designation
K. Actual or estimated weight of the item
Sheet # of multiple sheets in set
Other information (Surface finish, hardness, heat treatment etc.)

14. Listed in order of importance Manufactured or Purchased Part
Parts lists or Bill of Materials (BOM):
ANSI standards places it in the lower right corner above the titleblock
Listed in order of importance
Manufactured or Purchased Part
Information of standard parts is included (Catalog #, part name and size, etc.)
Information Provided:
Item #
Name of part
Part Material
Quantity
Company assigned part #
Other information (weight, stock size, etc.)

15. Zones Used on large sheets for reference purposes
(Letter and # designation used to specify location on drawing)

16. Revision Block
Per ANSI standard placed in upper right corner of drawing for room to expand down
What does it document?
Design Changes
Tooling Changes
Customer Requests
Errors, etc.
What does it contain?
Date
Name of person making change
Description of Change
Change #
Approval
Zone one drawing where change is taking place

17. Engineering Change Orders/ Notes
(ECO’s/ ECN’s)
Formal request for making a change to existing engineering drawings
Should contain:
Sketches w/ copy of original drawing
Written Description of Change
Reference # to trace change in future

18. and near any view not at that scale
Scale Specifications
Per ANSI standard placed in title block to call out majority of scales shown in each view,
and near any view not at that scale
(If Metric is used somewhere near the title block METRIC or SI should be clearly visible)
Common English Scales?
Full 1:1
Half 1:2
Quarter 1:4
Eighth 1:8
Double 2:1
Common Metric Scales?
Tenth 1:10
Twentieth 1:20
Fiftieth 1:50
Hundredth 1:100

19. Tolerance Specifications
Tolerance Dimensions
General Tolerance Note in Title block
GD&T
Classes of Fit
ANSI Standards:
One place decimal dimension = ± .1
Two place decimal dimension = ± .03
Three Place decimal dimension = ± .010
Angular Tolerances = ± .1˚
Interpret Dimensioning and Tolerancing per ASME Y

20. Redlining $$$$$$$$$$ Drawing is a legal contract
Thorough Check by several people for errors and consistency with industry and company standards
Why do companies have dedicated checkers?
$$$$$$$$$$
Drawing is a legal contract
between producer and client
Designer/ Drafter/ Engineer/ Checker check what?
Choice of views
Consistency
Dimensions
Approvals
Tolerances
Revisions
Clarity
Scale
Standard part specifications
Accuracy
Notes
Title block
Parts list

21. Used when several similar parts have common features (Family of Parts)
Tabular Drawings
Used when several similar parts have common features (Family of Parts)
U bolts
Casters
Air Cylinders

22. Threaded through supports
Homework
Figure :
20.49 Wheel Support
CHANGES:
1” HUB O.D.
Threaded through supports
½” washer on nut end

25. Tolerancing Fits of Size

26. Tolerancing Fits of Size

27. Smallest Hole = 1.0000 Largest Shaft = -1.0035 Interference = -.0035
For 1” or 1.000”
FN2 fit what are the tolerances?
Hole in Support = Upper limit
Hole in Support = Lower Limit
Outer Diameter of Bushing Upper limit
Outer Diameter of Bushing Lower Limit
Smallest Hole =
Largest Shaft =
Interference =
FN What?

28. Smallest Hole =.6250 Largest Shaft = -.6230 Clearance =.0020 RC What?
For 5/8” or .6250”
RC1 fit what are the tolerances?
Hole in bearing Upper Limit
Hole in bearing Lower Limit
Shaft of shoulder screw Upper limit
Shaft of shoulder screw Lower Limit
Smallest Hole =.6250
Largest Shaft =
Clearance =.0020
RC What?