1Mechanical and Aerospace Engineering Dept., SJSUKen Youssefi

Orthographic Projection

2 Dimensional View of an object

Ken Youssefi 2Mechanical and Aerospace Engineering Dept., SJSU

ME20/Tech20 – Engineering Design Graphics

Geometry and projection techniques.

• Graphics Theory

• Visualization

Ability to mentally process 3D information.

Drawing rules and industry practices.

• Standards & Conventions

Computer-Aided-Design (CAD) software (2D & 3D)

.AutoCAD (2D) and Pro/E (3D)

• Tools

Mechanical, Structural, Electrical, Architectural and

Art & Design, Industrial Design, …..

• Applications

Ken Youssefi 3Mechanical and Aerospace Engineering Dept., SJSU

Different Viewpoint

Ken Youssefi 4Mechanical and Aerospace Engineering Dept., SJSU

Parallel Projection

Perspective

Parallel

Ken Youssefi 5Mechanical and Aerospace Engineering Dept., SJSU

Orthographic Projection

Ken Youssefi 6Mechanical and Aerospace Engineering Dept., SJSU

Standard 2D views

Ken Youssefi 7Mechanical and Aerospace Engineering Dept., SJSU

Standard Views of Primitive Solids

Ken Youssefi 8Mechanical and Aerospace Engineering Dept., SJSU

View Orientation

Poor orientation

Good orientation

Ken Youssefi 9Mechanical and Aerospace Engineering Dept., SJSU

View Selection

Use minimum number of views to describe the object

Select the most descriptive views

Ken Youssefi 10Mechanical and Aerospace Engineering Dept., SJSU

Conventional PracticesHoles, Ribs & Webs – Principle of Revolution

Ken Youssefi 11Mechanical and Aerospace Engineering Dept., SJSU

Conventional Practices

Ken Youssefi 12Mechanical and Aerospace Engineering Dept., SJSU

Conventional Practices - Intersections

Ken Youssefi 13Mechanical and Aerospace Engineering Dept., SJSU

Miter Lines

Miter lines are used to transfer depth information.

O

45o line drawn from point O

Standard multiviews

Ken Youssefi 14Mechanical and Aerospace Engineering Dept., SJSU

Homework #1 – Due Friday 9/8multiviews

Problems 6, 26, 47, and 57 – page 276-280 (5th edition)

page 269-272 (4th edition)

page 364 (3rd edition)

Freehand sketch the three standard views (front, top, and right side). Select the left side of

the 3D drawing as the front view. Sketch 2 problems per page. Drawings should be somewhat proportional.

Ken Youssefi 15Mechanical and Aerospace Engineering Dept., SJSU

Conventional Practices - Tangency

Ken Youssefi 16Mechanical and Aerospace Engineering Dept., SJSU

Fillets, Rounds & Chamfers

Ken Youssefi 17Mechanical and Aerospace Engineering Dept., SJSU

Top view

Ken Youssefi 18Mechanical and Aerospace Engineering Dept., SJSU

Ken Youssefi 19Mechanical and Aerospace Engineering Dept., SJSU

Edge Lines – Principal & InclinedPrincipal lines appear vertical, horizontal or as point views. Inclined lines appear inclined in one view.

2

Ken Youssefi 20Mechanical and Aerospace Engineering Dept., SJSU

Edge Lines – Oblique

Oblique line appears inclined in all views

Ken Youssefi 21Mechanical and Aerospace Engineering Dept., SJSU

Principal PlanesPrinciple planes are parallel to principal orthographic planes

Ken Youssefi 22Mechanical and Aerospace Engineering Dept., SJSU

Inclined PlanesInclined planes are perpendicular to two opposite orthographic planes.

Ken Youssefi 23Mechanical and Aerospace Engineering Dept., SJSU

Oblique PlanesOblique planes are neither parallel nor perpendicular to any principal orthographic planes.

Ken Youssefi 24Mechanical and Aerospace Engineering Dept., SJSU

Type of Planes

Principal

Oblique

Inclined

Ken Youssefi 25Mechanical and Aerospace Engineering Dept., SJSU

Edge View of a PlanePrincipal planes appear in true size in one plane and as an edge

view in the other two planes.

Ken Youssefi 26Mechanical and Aerospace Engineering Dept., SJSU

Homework #2 – Due Friday 9/22/06

4th edition – page 369-374, 5th edition – page 376-381

freehand sketches, two drawings per page

Pictorials

1) Figure 7.61 – draw a perspective view, choose a vanishing point at the upper right hand corner

2) Problem 14 – draw an oblique view.

3) Problems 4, 22, and 27 – draw an isometric view, looking down, the left ,side of the isometric should be the front view.