chapter 15 pictorial drawings engineering drawing and design engineering drawing and design seventh...
TRANSCRIPT
Chapter 15Chapter 15
Pictorial Drawings
EngineeringDrawing and Design
EngineeringDrawing and DesignSeventh EditionSeventh Edition
15-1 Pictorial drawings-axonometric, oblique &
perspective• Used to explain complicated engineering
drawings to the untrained**• Help with design work in space• Train new employees in the shop• Speed up & clarify assembly of a machine• Transmit ideas• Aid in developing the power of visualization
PICTORIAL DRAWINGS
AXONOMETRIC PROJECTION
FRONT VIEW SIDE VIEW
PICTORIAL DRAWINGS
OBLIQUE PROJECTION
FRONT VIEW SIDE VIEW
PICTORIAL DRAWINGS
PERSPECTIVE PROJECTION
FRONT VIEW SIDE VIEW
Axonometric Projection
• The lines of sight are perpendicular to the plane of projection, but the 3 faces of a rectangular object are all inclined to the plane of projection*
• 3 forms of Axonometric Projection*– Isometric: 3 principal faces and axes are equally
inclined to the plane of projection– Diametric: 2 of the 3 are equally inclined– Trimetric: all 3 faces and axes of the object make
different angles with the plane of projection
PICTORIAL DRAWINGS
AXONOMETRIC PROJECTION
PICTORIAL DRAWINGS
TYPES OF AXONOMETRIC DRAWINGS
PICTORIAL DRAWINGS
TYPES OF AXONOMETRIC DRAWINGS
PICTORIAL DRAWINGS
TYPES OF AXONOMETRIC DRAWINGS
PICTORIAL DRAWINGS
AXONOMETRIC PROJECTION
USE OF THIS SET ENABLES YOU TO SHOW THEOBJECT FROM THESE 48 VIEWPOINTS.
PICTORIAL DRAWINGS
TYPES OF AXONOMETRIC DRAWINGS
USE OF THIS SET ENABLES YOU TO SHOW THEOBJECT FROM THESE 144 VIEWPOINTS.
Isometric drawings• Revolving the object at an
angle of 45⁰ to the horizontal so that the front corner is toward the viewer and then tipping the object up or down at 35⁰ 16’
• 3 visible faces appear equal in shape & side faces are at 30⁰ to horizontal*
• Isometric grid paper & ellipse templates aid sketching
• Vertical axis (height)• Left & right axes 30⁰ from
horizontal (length & width)• All lines drawn true length*• Hidden lines omitted• Nonisometric lines are
sloping surfaces and are created by locating their endpoints
15-2&3: Isometrics continued
• Circles on any of the 3 faces appear as an ellipse
• Isometric ellipse templates
• Fillets & rounds• Threads• Break lines• Isometric assembly
drawings
• Isometric sections are taken on a plane parallel to the face of one of the cubes
• Section lines are shown at 60⁰ with horizontal or in a horizontal position depending on where the cutting plane line is located
PICTORIAL DRAWINGS
ISOMETRIC AXES AND PROJECTION
PICTORIAL DRAWINGS
ISOMETRIC AXES AND PROJECTION
PICTORIAL DRAWINGS
DEVELOPING AN ISOMETRIC DRAWING
PICTORIAL DRAWINGS
SEQUENCE IN DRAWING AN OBJECT HAVING NONISOMETRIC LINES
PICTORIAL DRAWINGS
ORIENTING THE DIMENSION LINE, ARROWHEAD, AND EXTENSION LINE
PICTORIAL DRAWINGS
DIMENSIONING AN ISOMETRIC DRAWING
PICTORIAL DRAWINGS
ISOMETRIC GRID PAPER
PICTORIAL DRAWINGS
CURVED SURFACES IN ISOMETRIC
PICTORIAL DRAWINGS
SEQUENCE IN DRAWING ISOMETRIC CIRCLES
PICTORIAL DRAWINGS
DRAWING CONCENTRIC ISOMETRIC CIRCLES
PICTORIAL DRAWINGS
DRAWING ISOMETRIC ARCS AND CIRCLES
PICTORIAL DRAWINGS
ISOMETRIC SECTIONING
PICTORIAL DRAWINGS
ISOMETRIC SECTIONING
PICTORIAL DRAWINGS
CONVENTIONAL BREAKS IN ISOMETRIC
PICTORIAL DRAWINGS
FILLETS AND ROUNDS IN ISOMETRIC
PICTORIAL DRAWINGS
THREADS IN ISOMETRIC
15-4 Oblique projection
• This method is based on the procedure of placing the object with 1 face parallel to the frontal plane and placing the other 2 faces on oblique (receding) planes to left or right, top or bottom, at a convenient angle
• 3 axes of projection: horizontal, vertical, receding
• One face of the object is shown without distortion
Oblique projection: Cavalier and Cabinet Methods
• In cavalier all lines are made to their true length measured on the axes of projection
• Oblique sketching paper
• In cabinet, the lines on the receding axis are shortened by ½ their true length to approximate more closely what the human eye would see
• Cabinet is the more commonly used form especially for circles & arcs
PICTORIAL DRAWINGS
TYPES OF OBLIQUE PROJECTION
PICTORIAL DRAWINGS
OBLIQUE SKETCHES
PICTORIAL DRAWINGS
OBLIQUE PROJECTION
PICTORIAL DRAWINGS
DIMENSIONING AN OBLIQUE DRAWING
PICTORIAL DRAWINGS
OBLIQUE SECTIONS
PICTORIAL DRAWINGS
OBLIQUE ROUNDS AND FILLETS OBLIQUE BREAKS
OBLIQUE THREADS
15-6 Parallel or 1-point perspective
• Perspective is a method of drawing that depicts a 3-D object on a flat plane as it appears to the eye
• More realistic than axonometric or oblique• Main elements of a perspective drawing– Picture plane (plane of projection)– Station point (position of observer’s eye)– Horizon (imaginary horizontal line taken at eye level)– Ground line (base line off the picture plane & object)
PICTORIAL DRAWINGS
PERSPECTIVE PROJECTION
PICTORIAL DRAWINGS
PERSPECTIVE DRAWINGS
RECORDING THE PICTURE ON THE PICTURE PLANE
PICTORIAL DRAWINGS
TYPES OF PERSPECTIVE DRAWINGS
PICTORIAL DRAWINGS
ONE-POINT PERSPECTIVE
PICTORIAL DRAWINGS
ANGULAR, OR TWO-POINT PERSPECTIVE
PROJECT POINTS A AND B DOWN FROM PICTURE PLANE TO LOCATE POSITIONS OF LEFT AND RIGHT VANISHING POINTS
PICTORIAL DRAWINGS
ANGULAR PERSPECTIVE GRID
CAD APPLICATIONS
3D VIEWS MENU
CAD APPLICATIONS
3D SURFACES IN AUTOCAD
CAD APPLICATIONS
3D SURFACES PULL-DOWN MENU
CAD APPLICATIONS – SOLID MODELS
WIRE FRAME
CAD APPLICATIONS – SOLID MODELS
NURBS
CAD APPLICATIONS – SOLID MODELS
NURBS