engineering design and presentation introduction to orthographic projection or multiview drawings...

Post on 17-Dec-2015

224 Views

Category:

Documents

2 Downloads

Preview:

Click to see full reader

TRANSCRIPT

Engineering Design and Presentation

Introduction to Orthographic Projection or Multiview Drawings

Copyright © Texas Education Agency, 2012. All rights reserved.

What are Multiview Drawings?

Essentially every object has 6 sides that could be drawn.

2Copyright © Texas Education Agency, 2012. All rights reserved.

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.

3Copyright © Texas Education Agency, 2012. All rights reserved.

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.

4Copyright © Texas Education Agency, 2012. All rights reserved.

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.

5Copyright © Texas Education Agency, 2012. All rights reserved.

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.

6Copyright © Texas Education Agency, 2012. All rights reserved.

Correct Layout? Correct layout

shape should resemble the letter “L”.

Start with the top, then front, & then right side.

7Copyright © Texas Education Agency, 2012. All rights reserved.

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?”

8Copyright © Texas Education Agency, 2012. All rights reserved.

Graph Paper:

*Yes you will draw on this paper

9Copyright © Texas Education Agency, 2012. All rights reserved.

Now let’s look at the “TV Box” that we made.

10Copyright © Texas Education Agency, 2012. All rights reserved.

Count the # of squares for the FRONT View.

11Copyright © Texas Education Agency, 2012. All rights reserved.

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

Copyright © Texas Education Agency, 2012. All rights reserved.

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.

13Copyright © Texas Education Agency, 2012. All rights reserved.

14Copyright © Texas Education Agency, 2012. All rights reserved.

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

15Copyright © Texas Education Agency, 2012. All rights reserved.

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.

17Copyright © Texas Education Agency, 2012. All rights reserved.

18Copyright © Texas Education Agency, 2012. All rights reserved.

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

19Copyright © Texas Education Agency, 2012. All rights reserved.

And RIGHT SIDE views.

20Copyright © Texas Education Agency, 2012. All rights reserved.

21Copyright © Texas Education Agency, 2012. All rights reserved.

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.

22Copyright © Texas Education Agency, 2012. All rights reserved.

Should look like this, LIGHT LINES!

23Copyright © Texas Education Agency, 2012. All rights reserved.

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.

24Copyright © Texas Education Agency, 2012. All rights reserved.

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).

25Copyright © Texas Education Agency, 2012. All rights reserved.

Then Darken in the Visible/Object Lines

26Copyright © Texas Education Agency, 2012. All rights reserved.

NEAT & PRINTED Title Block Text!

27Copyright © Texas Education Agency, 2012. All rights reserved.

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!

28Copyright © Texas Education Agency, 2012. All rights reserved.

If you have done it correctly it will look like this.

Copyright © Texas Education Agency, 2012. All rights reserved.

DARKEST, make your Border / Title Block / “Picture Frame” the darkest line!

Copyright © Texas Education Agency, 2012. All rights reserved.

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

31Copyright © Texas Education Agency, 2012. All rights reserved.

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.

32Copyright © 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.

33Copyright © Texas Education Agency, 2012. All rights reserved.

top related