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Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3 Drafting Skills
Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
What is the difference between sketching and technical drawing? Is it necessary to use CAD to create drawings for a design project?
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved. Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Identify the important part of a CAD system used to create technical drawings.
Define the relevant terms related to CAD systems.
Recognize the traditional tools most often used to create technical drawings.
Recall the important terms related to traditional drawing tools.
Show the use of traditional tools and CAD to draw lines, circles, arcs, curves, and erase parts of a drawing.
Produce measurements and scale drawings through the use of scales, dividers, and CAD.
Identify standard pencil grades, and identify those most commonly used for technical drawing.
Recognize the types and thicknesses of the various lines in the alphabet of lines.
3 Drafting Skills
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved. Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
• All engineers should possess some basic skills as they enter the profession
• Sketches and technical drawings are products of the engineering design process
• Engineers must understand the principles behind drafting to work through the design process successfully
3 Drafting Skills
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Using Technical Drawing Tools
3.1 Drafting Tools
Computer-Aided Design/Drafting (CAD)
computer-aided design/drafting (CAD)computer software and related hardware that supplements or replaces traditional hand tools in creating models and technical drawings
>
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Identifying Computer-Aided Drawing Tools
3.1 Drafting Tools
CAD softwareapplication component of a computer-aided drawing system
>
A CAD System Consists of:
CAD Software
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Identifying Computer-Aided Drawing Tools
3.1 Drafting Tools
display devicesviewing component of CAD systems; also known as monitors
>
A CAD System Consists of:
CAD Software Display Devices
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Identifying Computer-Aided Drawing Tools
3.1 Drafting Tools
input devicesequipment used to enter data and interact with software programs such as CAD systems
>
A CAD System Consists of:
CAD Software Display Devices Input Devices
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Identifying Computer-Aided Drawing Tools
3.1 Drafting Tools
output devicesdevices such as printers, plotters, and film recorders, used to make hard copies of drawings created on screen
>
A CAD System Consists of:
CAD Software Display Devices Input Devices
Output Devices
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Identifying Computer-Aided Drawing Tools
3.1 Drafting Tools
storage devicemedium for storing and retrieving information as needed
>
A CAD System Consists of:
CAD Software Display Devices Input Devices
Storage DevicesOutput Devices
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Using Traditional Drawing Tools
3.1 Drafting Tools
Traditional Tools
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Using Traditional Drawing Tools
3.1 Drafting Tools
scaleinstrument used to measure distances on technical drawings
>
Pencils Eraser Paper
CAD TemplatesScale
templatesdevices used to assist in the drawing of repetitive features, such as circles and ellipses
>
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Using Traditional Drawing Tools
3.1 Drafting Tools
combination scaleinstrument used to measure distances that has engineering,
metric, and architectural components
>
Types of Scales
Combination Scale
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Using Traditional Drawing Tools
3.1 Drafting Tools
architect’s scaleinstrument used to create drawings of structures, such as a building or a factory floor layout
>
Types of Scales
Combination Scale Architect's Scale
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Using Traditional Drawing Tools
3.1 Drafting Tools
civil engineer’s scaledecimal scale used to divide into multiple units of 10
>
Types of Scales
Combination Scale Architect's ScaleCivil Engineer’s
Scale
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Using Traditional Drawing Tools
3.1 Drafting Tools
mechanical engineer’s scaleinstrument used to draw mechanical parts, either fractionally divided into 1/16 or 1/32, or decimally divided into 0.01 or 0.02
>
Types of Scales
Combination Scale Architect's ScaleCivil Engineer’s
Scale
Mechanical Engineer’s Scale
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Using Traditional Drawing Tools
3.1 Drafting Tools
metric scalescale used to create scaled technical drawings using SI units
>
Types of Scales
Combination Scale Architect's ScaleCivil Engineer’s
Scale
Mechanical Engineer’s Scale
Metric Scale
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Using Traditional Drawing Tools
3.1 Drafting Tools
International Standards Organization (ISO)international organization that established the metric standard
>
The International Standards Organization (ISO) developed the
International System of Units.
International System of Unitssystem of metric standard; also known as Systeme Internationale
>
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Using Traditional Drawing Tools
3.1 Drafting Tools
templatesdevices used to assist in the drawing of repetitive features, such as circles and ellipses
>
CAD Templates
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
1. Identify five traditional tools used in technical drawing.
3.1 Drafting Tools
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
2. Compare the architect’s, civil engineer’s, and mechanical engineer’s scales.
3.1 Drafting Tools
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3. Explain why an engineer might choose to use a CAD system instead of traditional drawing tools to create technical drawings.
3.1 Drafting Tools
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Drawing a Line Through Two Points
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Drawing Parallel Lines
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Drawing Perpendicular Lines
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Drawing Lines at Angles Relative to a Given Line
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Drawing Irregular Curves
To draw long, irregular curves, a device called a spline is used.
irregular curvestypes of curves that are not circles or arcs; also known as French curves
>
splinelong, flexible device used to draw long, irregular curves
>
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Using Multiview Projections
multiview drawingcollection of flat 2D drawings that work together to show an accurate representation of the overall object
>
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Using Multiview Projections
When creating a multiview drawing of a design, the selection and orientation of the front view is an important first step.
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Using Multiview Projections
Isometric Orthographic
isometricview of a sketch of an object in a three-dimensional view
>
orthographicview or sketch of an object that shows how an object looks from the front, top, right, or other views
>
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Using the Multiview Sketching Techniques
There is a certain technique, or standard set of methods, followed when creating multiview sketches.
The technique includes line conventions, proportioning, and methods for creating circles, arcs, and ellipses.
multiview sketchescollection of drawings that require certain line conventions, proportioning, and methods for creation
>
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Using the Multiview Sketching Techniques
Sketched Alphabet of Lines
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Using the Multiview Sketching Techniques
Line Types on an Engineering Sketch
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Using the Multiview Sketching Techniques
Precedence of Lines
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Using the Multiview Sketching Techniques
Center Line Conventions
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Lettering
Examples of ANSI Standards
ANSI standardsset of standards used in an industry set by the American National Standards Institute
>
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Lettering
font
size and style of a particular typeface >
Most CAD systems can make use of the same fonts available in word processing systems.
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Lettering
type sizemeasurement, in points, of text size
>
Type size is measured in points.
There are 72 points per vertical inch.
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Lettering
Important Text Terms
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Lettering
Other CAD Text Variables
Text Slant Text Rotation Text Aspect Ratio
text slantvariable used to create individual text characters at an angle away from vertical
>
text rotationangle, measured from horizontal, used to create entire lines of text at an angle
>
text aspect ratio
numerical ratio of the width versus the height of individual characters >
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3.2 Drafting Techniques
Lettering
Including Text on Drawings
TitleBlock
RevisionBlock
Bill ofMaterials
GeneralNotes
Dimensions
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
1. Explain how different types of straight lines can be drawn.
3.2 Drafting Techniques
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
2. Summarize the types of text that are included on technical drawings.
3.2 Drafting Techniques
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
3. Evaluate the need to use conventions in drawing hidden line on technical drawings.
3.2 Drafting Techniques
Chapter 3 Drafting Skills Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
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