PowerPoint Presentation: Chapter 5 Pictorial Sketching
PowerPoint Presentation: Objectives Be able to explain the difference between an axonometric projection and an oblique projection . Be able to explain the difference between an isometric projection and an isometric drawing/sketch . Be able to create an isometric and oblique sketches from an actual object and multiview drawing .
PowerPoint Presentation: Axonometric & Oblique Projection
PowerPoint Presentation: Axonometric Projection A B C D Parallel & normal to picture plane Line of sight A B C D
PowerPoint Presentation: Axonometric Projection Type of axonometric drawing a b c 2. Dimetric Two angles are equal. b a c 3. Trimetric None of angles are equal. a b c 1. Isometric All angles are equal. A B C D A B C D Axonometric axis Axonometric axis Axonometric axis
PowerPoint Presentation: A B C D Line of sight Parallel & oblique to picture plane Oblique Projection A D C B
PowerPoint Presentation: Oblique Projection A D C B B C D A Oblique drawing angle 30 o 45 o 60 o Type of Oblique drawing 45 o 45 o 1) Cavalier 2) Cabinet Full scale Half scale
PowerPoint Presentation: Isometric Projection & Isometric drawing
PowerPoint Presentation: Rotate 45 about vertical axis Tilt forward (35 o 16 ’ ) Isometric Projection All edges foreshorten about 0.8 time.
PowerPoint Presentation: Isometric Drawing Isometric drawing is a drawing drawn on an isometric axes using full scale . Isometric projection (True projection) Isometric drawing (Full scale) Forshorten Full scale
PowerPoint Presentation: Positions of Isometric Axes Isometric axes can be arbitrarily positioned to create different views of a single object. Regular isometric Reverse axis isometric Long axis isometric View point is looking down on the top of the object. View point is looking up on the bottom of the object. View point is looking from the right (or left) of the object.
PowerPoint Presentation: Distance in Isometric Drawing Isometric line is the line that run parallel to any of the isometric axes. Isometric axes True-length distances are shown along isometric lines. Nonisometric lines
PowerPoint Presentation: Isometric Sketching
PowerPoint Presentation: 2. Define an isometric axis. 3. Sketching the enclosing box. 4. Estimate the size an and relationship of each details. 5. Darken all visible lines. 1. Place the object in the position which its shape and features are clearly seen. Sketch from an actual object
PowerPoint Presentation: STEPS 1. Positioning object. 2. Select isometric axis. 3. Sketch enclosing box. 4. Add details. 5. Darken visible lines. Sketch from an actual object
PowerPoint Presentation: 1. Positioning object. 2. Select isometric axis. 3. Sketch enclosing box. 4. Add details. Note In isometric sketch/drawing), hidden lines are omitted unless they are absolutely necessary to completely describe the object. Sketch from an actual object STEPS 5. Darken visible lines.
PowerPoint Presentation: 1. Interprete the meaning of lines / areas in multiview drawing. 2. Locate the lines or surfaces relative to isometric axis. Sketch from multiview drawing
PowerPoint Presentation: Front View Top View Side View Example 1 : Object has only normal surfaces Bottom View Bottom Front Side Side Front Top Regular Reverse W D H H D W
PowerPoint Presentation: Example 2 : Object has inclined surfaces W H q D y x Front View y x Nonisometric line
PowerPoint Presentation: Nonisometric line A A x y x x B B A B C C C x y Example 3 : Object has inclined surfaces
PowerPoint Presentation: A A B B C D E D E F F x y Front View Regular C Example 4 Reverse
PowerPoint Presentation: Circle & Arc in Isometric In isometric drawing, a circle appears as an ellipse. 2. Construct an isometric square. 3. Sketch arcs that connect the tangent points. Sketching Steps 1. Locate the center of an ellipse.
PowerPoint Presentation: Circle & Arc in Isometric 3. Construct a perpendicular bisector from each tangent point. 4. Locate the four centers. 5. Draw the arcs with these centers and tangent to isometric square. Sketching Steps Four-center method is usually used when drawn an isometric ellipse with drawing instrument. 2. Construct an isometric square. 1. Locate the center of an ellipse.
PowerPoint Presentation: Example 5
PowerPoint Presentation: Irregular Curve in Isometric 1. Construct points along the curve in multiview drawing. 2. Locate these points in the isometric view. 3. Sketch the connecting lines. Steps
PowerPoint Presentation: Oblique Sketching
PowerPoint Presentation: Object Orientation Guidelines Place complex features (arc, hole, irregular shape surface parallel to frontal plane.
PowerPoint Presentation: Object Orientation Guidelines The longest dimension of an object should be parallel to the frontal plane. GOOD WORSE GOOD WORSE
PowerPoint Presentation: Object Orientation Guidelines Which orientation is better ?
PowerPoint Presentation: D 45 ESTIMATE DEPTH ESTIMATE LINES Sketch from actual object
PowerPoint Presentation: Sketch from multiview drawing
PowerPoint Presentation: Sketch from multiview drawing
PowerPoint Presentation: A B C D E Sketch from multiview drawing
PowerPoint Presentation: A B C D E Sketch from multiview drawing
PowerPoint Presentation: A B D E C Sketch from multiview drawing
PowerPoint Presentation: A B D E C Sketch from multiview drawing