engineering graphics basic drafting facts and tools copyright © texas education agency, 2012. all...
TRANSCRIPT
Engineering Graphics
Basic Drafting Facts and Tools
Copyright © Texas Education Agency, 2012. All rights reserved.
What is the difference between Sketching & Drafting?
Essentially the difference is that when you are sketching, you ONLY use a pencil and your hand.
The minute you use a tool like a triangle, you are drafting, because a tool helps you draw things more precisely.
2Copyright © Texas Education Agency, 2012. All rights reserved.
How many views does every object have?
They are six (6) views we could draw, but we only draw three (3).
Top, Front, & Right Side.
We will cover these more in depth later.
3Copyright © Texas Education Agency, 2012. All rights reserved.
We draw oblique pictorials, of which the front view angle is 900 and the sides are 450.
Cabinet = Full depth Cavalier = ½ depth
We will cover these more in depth later4Copyright © Texas Education Agency, 2012. All rights reserved.
We draw isometric pictorials in which all of the views are drawn at 300.
We will cover these more in depth later5Copyright © Texas Education Agency, 2012. All rights reserved.
Different lines we could draw.
There actually many more, these are just the basics.
We will cover these more in depth later.
6Copyright © Texas Education Agency, 2012. All rights reserved.
Straight Edge Guides
Purpose is to line up drawings and keep everything square.
Drafting Arm
T Square
Parallel Bar
8Copyright © Texas Education Agency, 2012. All rights reserved.
Templates
Quickly and accurately draw objects that are drawn often.
There are MANY more, each for it’s own use.
Examples: architectural, landscape, electronics, etc.
Circle Templates
Ellipse Template
9Copyright © Texas Education Agency, 2012. All rights reserved.
Drawing
Mechanical Pencils: for drawing, use the .5mm for all general work. Use the .7mm for darker or finished work.
.5mm is the “work horse”keep all lines light until you are finishing it up.
Eraser Shield is for erasing parts of the drawing. It will help keep you from erasing the parts that are correct.
Lettering Guide is used to create guide lines for lettering.
Mechanical Pencils (2)
.5mm & .7mm
Eraser Shield
AMES Lettering Guide
10Copyright © Texas Education Agency, 2012. All rights reserved.
Irregular Curves
Used to help draw circular items.
Examples: ellipses, cycloids, etc.
Flexible Curve
French Curves
11Copyright © Texas Education Agency, 2012. All rights reserved.
Clean Up ToolsUsed to erase
mistakes.
Used to clean off your drawing & work station.
NEVER use just your hand to clean up or you will smear the lead!
Eraser
ALWAYS clean up behind yourself! Leave the station as clean, or cleaner, than when you used it!
Brush
12Copyright © Texas Education Agency, 2012. All rights reserved.
Layout ToolsCompass is used to
draw precise circles, arc, etc.
Can also be used to help layout marks.
Divider is used to get precise measurements, & transfer measurements.Divider
Bow Compass
13Copyright © Texas Education Agency, 2012. All rights reserved.
TrianglesUsed to draw perfectly
square lines with the straight edges tools.
Each has the most commonly used angles required.
When combined, they can get you all of the other angles you might need.
30/60 Triangle “Tall & Skinny”
45 Triangle “Short & Fat”
600
300
450
450
14Copyright © Texas Education Agency, 2012. All rights reserved.
Drafting Scales
Used to draw objects precisely or exactly.
Engineers: deals primarily with inches and based on 10 “parts”.
Architectural: deals with feet & inches.
16 is regular ruler. All other the fractions represent a foot or 12”.
Metric based on MM & 10 “parts”. Refer to lessons on Scales for
more information.
15Copyright © Texas Education Agency, 2012. All rights reserved.
Summary
You need to know your tools and how to correctly use them.
Yes, Auto CAD is the most used tool, but you must understand how the process works. Then, you’ll become a better drafter.
Also, very often you maybe called upon to draw something with no computer around, so you will be better prepared if you know these tools and how to use them.
16Copyright © Texas Education Agency, 2012. All rights reserved.
Remember to….
Use this information to complete the “ABC” Review Sheet for this lecture.
17Copyright © Texas Education Agency, 2012. All rights reserved.
BONUS: Want to learn more about the history of drafting?
Essentially, drafting has been around since man first started drawings.
Write a 1 page synopsis about what you learn about the History of Drafting.
This website has an excellent explanation of the History of Drafting.
http://www.uen.org/utahlink/tours/tourViewCategory.cgi?category_id=21312&tour_id=14435
18Copyright © Texas Education Agency, 2012. All rights reserved.
Textbook
Texas approved publishers are: Goodheart-Willcox Delmar Learning Prentice Hall
All have a companion workbook’s with more problems. I recommend using it, or any other approved textbook, i.e., if you are ATC or TechPrep and must teach using local colleges textbook.
19Copyright © Texas Education Agency, 2012. All rights reserved.b