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2D EssentialsInstructor: Laura Gerold, PECatalog #10614113Class # 22784, 24113, 24136, & 24138Class Start: January 18, 2012 Class End: May 16, 2012

Questions . . .

When you are working on plans that will be used in Europe or Asia.

When do you include the projection angle symbol on plans?

ELLIPSE TEMPLATES

These ellipse guides are usually designated by the ellipse angle, the angle at which a circle is viewed to appear as an ellipse.

DRAWING A FOCI ELLIPSE Major axis = long axis of ellipse Minor axis = short axis of ellipse The foci of the ellipse are two special points E

and F on the ellipse's major axis and are equidistant from the center point. The sum of the distances from any point P on the ellipse to those two foci is constant and equal to the major axis ( PE + PF2= 2A ). Each of these two points is called a focus of the ellipse.

DRAWING A FOCI ELLIPSE Let AB be the major axis and CD the minor axis To find foci E and F, draw arcs R with radius equal to half

the major axis and centers at the end of the minor axis Between E and O on the major axis, mark at random a

number of points. Using a random point (point 3), with E and F as centers

and radii A-3 and B-3, draw arcs to intersect at four points 3’. Use the remaining points to find four additional points on the ellipse in the same manner.

Sketch the ellipse lightly through the points

Drawing an Ellipse

Draw a major axis 5” long and a minor axis 2.5” long. Draw an ellipse by the foci method with at least five points in each quadrant

DRAWING AN ARC TANGENT TO TWO LINES AT ACUTE OROBTUSE ANGLES Given two lines not making a 90° Draw lines parallel to the given lines at distance R from

them to intersect at C the center From C, drop perpendiculars to the given lines to locate

tangent points, T With C as the center and with given radius R, draw the

required tangent arc between the points of tangency

DRAWING AN ARC TANGENT TO TWO LINES AT ACUTE OROBTUSE ANGLES

Draw two intersecting lines at an acute angle, each 2.5 inches long

Draw a 1.5 inch radius arc tangent to the two lines

{TEST REVIEW

50You have the entire class period to complete the test

How Many Questions are on the Test?

True and False Multiple Choice Fill in the Blank Essay Questions Drawing

How are the questions formatted?

All of your drawing utensils A Calculator

This is NOT an open book exam. Other electronic devices can not be

used in place of a calculator

What can I bring?

Circles Squares Bisect an angle Perpendicular Bisect a line Triangles Orthographic Sketches Alphabet of Lines Lettering

What do I need to know how to draw?

Chapter 1 Chapter 2 Chapter 3 (Sections 1-5) Chapter 4 Chapter 5

What Chapters in the Book Will be Covered?

Class Notes (Power Points on Blackboard)

Class Notes you took Homework Textbook

What Should I Use to Study?

Identify and Describe the five phases of the design process

Identify what technical drawings are used for Identify why drawing by hand is still useful Identify who creates technical drawings and

what professions use them Draw & Identify the Alphabet of Lines

Potential Topics on Test

Apply civil engineering scales to sketches of simple objects

Apply architectural scales to sketches of simple objects

Scale a drawing up or down using scale ratios (ex 1:2, 2:1)

Apply standard lettering practice and standards to sketches

Identify negative space

Potential Topics on Test

Describe Prisms Describe Cylinders Describe Pyramids Describe Cones Describe Spheres Describe a Torus Describe Ellipsoids

Potential Topics on Test

Describe Parallelograms Describe a Trapezoid Describe a Trapezium Describe a Regular Polygon up to 8 Sides Describe a Circumference of a Circle Describe Diameter of a Circle Describe Radius of a Circle Describe a Quadrant of a Circle Describe a Chord of a Circle Describe Concentric Circles Describe Eccentric Circles Identify the point at which a line is tangent to an arc Identify the pint at which an arc is tangent to an arc

Potential Topics on Test

Differentiate between the 1st and 3rd Angle Projection

Name and position the 6 primary views Create orthographic sketches of simple

objects Transfer dimensions Apply hidden line conventions to sketches Apply line precedence conventions to

sketches

Potential Topics on Test

Write down a question that you still have about a topic that will be covered on the test.

Share the question and topic with your group

As a group determine the answer to the question

Still stumped? Ask a neighboring group Classroom stumped? Save the question for

the end and ask me

What are you confused about?

It’s time for a review game!

Stand up and Stretch . . .

Which Team Will Dominate? Winning team will each receive 5 extra credit points.

Pick a team name Team members pick a category and answer the next

question in that category All question are answered in order starting with 1 then

2, etc. If the team answers correctly, they get 2 points If they have to use their text to answer, they only get 1

point If nobody on the team is able to answer the question

correctly, they can say “pass.” The next team gets a chance to answer for 1 point.

Information Domination

Design Process 1, 2, 3, 4, 5 Alphabet of Lines 1, 2, 3, 4, 5, 6 Scales 1, 2, 3, 4, 5 Lettering 1, 2, 3, 4 Solids 1, 2, 3, 4, 5, 6, 7, 8 Planar Shapes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Orthographic Sketches 1, 2, 3, 4, 5, 6, 7, 8

Information Domination

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Ready for the Test??

Any additional questions??

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Chapter 5 – ORTHOGRAPHIC PROJECTION

VIEWS OF SURFACESThere are terms used for describing a surface’s orientation to the plane of projection. The three orientations that a plane surface can have to the plane of projection are normal, inclined, and oblique.

Note how a plane surface that is perpendicular to a plane of projectionappears on edge as a straight line

Wisconsin House Hotel – Normal Surfaces

A normal surface is parallel to the plane of projection

It appears its true shape and size on orthographic drawings.

A edges are true length on plane of projection

Normal Surfaces

Use your blocks to make a creation different than last week

Sketch the three necessary views

“Normal” Group Project

Heritage Hill – Inclined Surfaces

An inclined surface is perpendicular to one plane of projection

It is inclined or tipped to adjacent planes Inclined edge is parallel to one plane of projection

and appears true length on this plan (appears as angled line)

Inclined edge appears as a foreshortened line on adjacent planes (appears as horizontal or vertical line)

Inclined Surfaces

Each group gets a right triangular prism

Draw the three necessary views

What was different about drawing the inclined planes versus the normal planes (with the blocks)?

“Inclined” Group Project

Milwaukee Art Museum – Oblique

Surfaces

An oblique surface is tipped on all principal planes of projections

It does not appear on edge or true size in any standard view

An oblique edge appears foreshortened and at an angle in every view

Oblique Surfaces

As a group, try to think of any oblique surfaces you have seen at home, work, or on your way here tonight.

Sketch up a few and present to class

“Oblique” Group Project

ANGLES

If an angle is in a normal plane (a plane parallel to a plane of projection) it will show true size on the plane of projection to which it is parallel.

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Chapter 6 – 2D Drawing Representation

Conventional Representations

Standard orthographic projections don’t always show complex shapes as clearly and simply as you may wish, so certain alternative practices, referred to as conventions, are accepted.

Conventions are like rules for breaking the rules. Note how these views are projected

Orthographic Views of Intersecting and Tangent Surfaces. (Lockhart, Shawna D.; Johnson, Cindy M., Engineering Design Communication: Conveying DesignThrough Graphics, 1st, © 2000. Printed and Electronically reproduced by permission of Pearson Education, Inc., Upper Saddle River, New Jersey.)

What do you notice on these drawings?

Can’t always show all views on a sheet

When this is the case, use a removed view

Two ways to show this. . .

Removed Views

Removed Views – Type 1

Use a View Indicator arrow to show direction of sight

Removed Views – Type 2

Use a Viewing Plane Line

Remove a View from one of your group drawings of today

Create a removed view plane using an indicator arrow or viewing plane line

Group Project – Removed Views

Manufactured Features

• Fillet

• Round

• Counterbore

• Countersink

• Spotface

• Boss

• Lug

• Flange

• Chamfer

• Neck

• Keyway/Keyseat

• Knurl

• Bushing

For class on March 21st, bring in objects with “manufactured features” for use in group projects

Manufactured Features

Overview of Drafting

Review of Drafting

What’s Next?

• Test next week – March 7th

• Spring Break March 14th - NO CLASS• Finish Chapter 6 – 2D Drawing

Representation on March 21st

Questions?

On one of your sketches, answer the following two questions: What was the most useful thing that

you learned today? What do you still have questions

about?

Homework – Due March 21st!

Chapter 5 Review Question: 5Chapter 5 Exercises: 5.2, 5.5 (9), 5.6 (8– no isometric drawing)