Post on 05-Jan-2016
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.