1. Chapter 18
Working Drawings

2. Objectives
Specify the contents, formatting, and organization of engineering drawings
Correctly prepare and interpret formal, professional engineering drawings

3. Objectives (cont’d.)
Discuss the primary differences between drawings used in manufacturing projects and those used in construction projects
Effectively use scales to measure the length of lines on a drawing

4. Introduction Manufacturing vs. construction drawings
For fabrication or construction, drawings must be presented in formal and professional manner
Must be interpreted in same way by everyone
Engineering drawings considered legal documents
Reflect on quality of originator

5. Making It Formal Working drawings
Show each part in all views necessary to define features, sizes, tolerances, and assembly method
Have prescribed presentation form
Should be organized, neat, and polished

6. Making It Formal (cont’d.)
FIGURE The typical progression of the design of a part from a conceptual hand sketch to a computer 3-D model to a formal working drawing extracted from the model.

7. Sheet Sizes
FIGURE Some relative standard sheet sizes, international and US, used for formal drawings.

8. The Formal Drawing Header in Manufacturing Drawings
FIGURE A typical header for a formal engineering drawing.

9. The Formal Drawing Header in Manufacturing Drawings (cont’d.)
FIGURE Inside the main
title block, the definitions of the
units, scale, and projection angle help the reader to correctly interpret the placement and orientation of the views and the dimensions that are shown on them.
FIGURE The name of the company, a statement of ownership of the drawing contents, and conditions of use are permanently printed in the title block.

10. The Formal Drawing Header in Manufacturing Drawings (cont’d.)
FIGURE Signatures and
dates help establish the history
of development and leave a trail
of accountability.

11. The Drawing Area for Manufactured Parts
Geometry presentation
Area showing object’s geometry should be uncluttered
Complicated objects require larger sheets or multiple sheets

12. Object Views
Use rule of orthogonal projection and multiview representation
Show as many visible edges in their true length as possible
General rule for presenting object
Start with preferred configuration
Add or subtract whatever views are necessary to best show all of the geometry

13. Notes
Special processing, handling, or assembly procedures that are required but cannot be specified by dimensions and tolerances or by materials specifications
Usually numbered and listed together
Generally added whenever you want something done to a part and you do not know how else to specify it

14. Parts, Subassemblies, and Assemblies
FIGURE A set of drawings for a project is organized like the roots of a tree. Individual parts fit into subassemblies or the main assembly. Subassemblies fit into higher subassemblies or the main assembly.

15. Exploded Assembly Drawings
FIGURE An exploded
assembly drawing including a bill of materials for a
machine vise.

16. Outline Assembly Drawings
FIGURE An outline assembly drawing of the machine vise.

17. Sectioned Assembly Drawings
FIGURE A sectioned assembly drawing of the machine vise.

18. The Bill of Materials
Text list of parts, subassemblies, and subassembly parts
Item number, corresponding part number, part name, material from which part is made, and number of times part is used in assembly
Can appear on any assembly drawing or as separate drawing or document
Usually printed as a table on an assembly drawing

19. Manufacturing Detail Drawings
FIGURE Detail drawings for the machine vise.

20. Manufacturing Detail Drawings (cont’d.)
FIGURE Detail drawings for the machine vise. (continued)

21. Manufacturing Detail Drawings (cont’d.)
FIGURE Detail drawings for the machine vise. (continued)

22. Manufacturing Detail Drawings (cont’d.)
FIGURE Detail drawings for the machine vise. (continued)

23. More Examples of Manufacturing Drawings
FIGURE Working drawings for the computer disk drive spindle.

24. More Examples of Manufacturing Drawings (cont’d.)
FIGURE Working drawings for the computer disk drive spindle. (continued)

25. More Examples of Manufacturing Drawings (cont’d.)
FIGURE Working drawings for the computer disk drive spindle. (continued)

26. More Examples of Manufacturing Drawings (cont’d.)
FIGURE Working drawings for the computer disk drive spindle. (continued)

27. More Examples of Manufacturing Drawings (cont’d.)
FIGURE Working drawings for the computer disk drive spindle. (continued)

28. More Examples of Manufacturing Drawings (cont’d.)
FIGURE Working drawings for the computer disk drive spindle. (continued)

29. Construction Drawings
Why construction drawings are different from manufacturing drawings
Construction projects
Typically site-specific and large-scale
Often use the English system of units
Do not often use 3-D modeling
Are always built from the ground up

30. How Construction Drawings Are Different from Manufacturing Drawings
Profile views vs. plan views vs. elevation views
Documentation
Set of construction plans
Specifications (specs)

31. How Construction Drawings Are Different from Manufacturing Drawings (cont’d.)
Bearings
Control points
Benchmarks
Site survey
Existing features or structures

32. How Construction Drawings Are Different from Manufacturing Drawings (cont’d.)
Construction projects too large and expensive to build prototypes
However, small-scale models sometimes used
Unforeseeable problems likely
Changes tracked on as-built drawings

33. Construction Plans Large number of drawings Schedules of materials
Cover sheet, site plan, elevation views, foundation plan, floor plans, electrical plans, roofing plans, sections, detail drawings, etc.
Schedules of materials
PE is legally responsible

34. Cover Sheet
FIGURE Cover sheet and index for the Baraga water treatment plant expansion project.

35. Site Plan
FIGURE Site plan for Baraga water treatment facility showing existing structure as well as nearby highway.

36. Elevation Views
FIGURE Elevation view for overflow and drain portion of lagoon.

37. Foundation and Floor Plans
FIGURE First floor plan
for the Baraga water treatment
facility.

38. Sections FIGURE 18.38. General section through a house showing room
layouts.

39. Detail Construction Drawings
FIGURE Detail drawings showing how a door will be installed in the Baraga water treatment facility.

40. Plan and Profile Drawings
FIGURE
Plan and profile drawing showing the street and corresponding sewage pipe for wastewater system in Baraga.

41. Engineering Scales Virtually all engineering drawings made to scale
Ratios
2:1 means two inches on paper equals one inch on object
Scale indicates how close you are to object

42. Engineer’s Scale
FIGURE Line to be measured at a scale of 1"=200' and a 20 Engineer’s scale.
FIGURE Lines drawn at a scale of 1"=40' and a 40
Engineer’s scale.

43. Metric Scale FIGURE 18.47. Line drawn at a scale of 1:2000 and a 1:20
FIGURE Lines drawn at 1:1 scale and a 1:100 Metric scale.

44. Architect’s Scale
FIGURE Line drawn at a scale of 1⁄4"=1'-0" and a 1⁄4" Architect’s scale.
FIGURE Line drawn at a scale of 1⁄8"=1'-0" and a 1⁄8" Architect’s scale.

45. Considerations for 3-D Modeling
Easy to generate:
Different views
Dimensions
Headers
Software cannot fully interpret functional requirements
E.g., acceptable dimension tolerances

46. Summary
Learned that drawings must be able to communicate desires of engineer or designer
Discussed formal drawing format with proper views, sheet sizes, headers, and drawing organization
Discussed different types of scales and their physical meaning