Post on 17-Dec-2015
Engineering Design and Presentation
Introduction to Orthographic Projection or Multiview Drawings
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What are Multiview Drawings?
Essentially every object has 6 sides that could be drawn.
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Question: What views do you think we draw?
We only draw three (3) of the views because it would be redundant to draw, say the back, because it’s the same as the front.
So we only draw the Top, Front, & Right Side.
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Why only draw these views? We only draw the views needed to fully
show the shape of the object. Choose the view that shows the most
information; that will be your Front View. In some other countries, they do draw the
left view; but, in general, you should draw the right side.
Showing only these three views saves time, makes the drawing easier to understand, and it’s all you need to have to the object manufactured.
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Why do we draw hidden lines?
Hidden lines are used to show something that you can’t see in that view, but you need to know where it is.
Hidden lines need to be drawn correctly and uniformly so that they are easy to see.
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What is difference between an orthographic projection and a drawing?
The result of a orthographic projection is the multiview drawing.
Surfaces of the object are shown in true size/dimension and/or shape.
Follow all drafting and dimensioning rules for drafting like line types, correct tool usage, etc.
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Correct Layout? Correct layout
shape should resemble the letter “L”.
Start with the top, then front, & then right side.
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Points to Ponder:
Pencil Point To Ponder: “Why do you think we only use a pencil & not pens?”
Triangle Point To Ponder: “Why do you only use a triangle and never a scale or ruler for drawing straight lines?”
Draw LIGHT lines and go back to darken when done. Point To Ponder: “Why do we do this?”
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Graph Paper:
*Yes you will draw on this paper
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Now let’s look at the “TV Box” that we made.
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Count the # of squares for the FRONT View.
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Measure 3.5 squares to right & left of the center mark.
Line up bottom of triangle to get straight Vertical lines.
3.5 3.5
12
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If you are drawing it right, the views – lines – measurements will all line up. Think the “L” format (Lined Up).
Use either triangle when drawing a line to keep it uniform & neat/straight.
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Repeat the process by looking at the Front View. Lightly draw
what you see centered on the construction lines you drew
already. It should look like this.
Construction Line or Center Mark Top View
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Project your lines over all ways.16Copyright © Texas Education Agency, 2012. All rights reserved.
Count the squares and
LIGHTLY draw them centered
over the construction
lines you already drew for the TOP
view.
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Looking at the Top View, lightly draw what you see centered on the construction lines you drew already. It should look like this.
Construction Line or Center Mark
Top View
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And RIGHT SIDE views.
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Repeat the process by looking at the Right Side
View, lightly draw what you see so that it fits in the box. Think “connect the dots” to finish it up. It should look
like this.
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Should look like this, LIGHT LINES!
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Draw Projection Lines to meet the angle line. Then
draw straight down.
Construction Line or Center Mark Top View
Do the same for the horizontal lines in the Front View.
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This is what it will look like if
you did it right. ALL lines are light! See how the views
line up and meet. That means less
measuring and work for us!
“L” Format (Lined Up).
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Then Darken in the Visible/Object Lines
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NEAT & PRINTED Title Block Text!
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Make sure that you Dimension EACH of your drawings!
Because when you remove the master graph paper, you will need know these sizes for
future use!
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If you have done it correctly it will look like this.
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DARKEST, make your Border / Title Block / “Picture Frame” the darkest line!
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Now, grade yourself using the rubric on each paper. Notice how the points change. The points given is the MAX you could receive for each problem.
I will be going back and checking these. I will adjust as needed, so be HONEST! Otherwise, the score drops auto 5 pts if you give yourself, say 25 pts, when you only deserve 22 pts.
2 3
4 5
4 22
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Remember to….
Always darken in your titleblock’s border.
Always neatly letter your text. Complete the self assessment rubric,
your teacher will double check this. Tomorrow you will draw more
complicated multiviews but with less instructions just examples shown.
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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.
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