## ENG 004 Lecture 16, Nov 19, 2012

### Announcements

• Homework #6 due now
• Homework #7 will be posted this afternoon

### Topics

• Geometric Dimensioning and Tolerancing
• Working Drawings

## Five Step Process

1. Isolate and define the functions of the feature/part.
2. Prioritize the functions.
3. Identify the datum reference frame based on the functional properties and control the datum features.
4. Select the proper control.
5. Calculate the tolerance values.

## Working Drawings

### Other Names

Detail drawings, production drawings, final drawings

### Definition

The complete set of standardized drawings specifying the manufacture and assembly of a product based on its design.

Working drawings are either multi-view drawings of a single part providing all the detail necessary to manufacture the part of an assembly drawing showing how previously manufactured parts are put together.

Includes: detail drawings of each non-standard part, an assembly or subassembly drawing showing all the standard and nonstandard parts in a single drawing, a bill of materials, a title block.

### Assembly drawings

are sometimes represented as an exploded pictorial drawing.

### Specifications

Written instructions

## Scale

Views should be scaled to fit on the paper.

Block in boundaries of views to space

Stay within the borders

Views should be aligned, if not they should be labeled

## Common Scales

### English

• 1 = 1: Full
• 1 = 2: Half
• 1 = 4: Quarter
• 1 = 8: Eighth
• 1 = 10: Tenth
• 2 = 1: Double

### Metric

• 1:1 Full
• 1:2 Half
• 1:5 Fifth
• 1:10 Tenth
• 1:20 Twentieth
• 1:50 Fiftieth
• 1:100 Hundredth

## Title Blocks

Used to record all the important information necessary for the working drawings.

• Usually located in the lower right corner
• ANSI Standards
• Continuation block on other sheets may not have as much detail as first sheet

## Common Elements in Title Blocks

• Name and address of Organization/Company
• Title of the drawing
• Drawing number
• Names and dates of the drafters, designer, checker, engineer, issue date, contract number, etc.
• Design approval
• Predominant scale
• Sheet number and sheet size
• Default tolerances
• Units of measure
• Material
• Special finishes
• Weight of the item

## Example Working Drawings

• revision blocks
• borders/zone
• common parts
• parts list
• notes
• hole tables
• detail views
• general tolerances
• exploded view

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