Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 81Lecture #2 EGR 110 – Engineering GraphicsReading Assignment: Ch. D in Engineering Graphics Workbook, Series 1.2 or Series 2Sketching Assignment: Sketching Assignment #2Chapter D: Orthographic ProjectionLast week we concentrated on sketching multi-view drawings when given an isometric drawing.This week we will concentrate on sketching isometric drawings when given multi-view drawings.Multi-view DrawingIsometric2Lecture #2 EGR 110 – Engineering GraphicsIsometric Sketching•Isometrics are 2D pictorial drawings that give the impression of being 3D.•Isometrics are primarily intended for visualization.•Isometrics are often not scaled since the lengths of lines may be unscaled in order to give the proper 3D impression.•Isometric sketches use "isometric axes" as shown. •Isometric graph paper is commonly used to sketch isometrics. Be sure that the angled lines form 30 angles with the horizontal and not with the vertical (i.e., the paper can be used only with portrait or landscape orientation, not both). O30 O30Isometric AxesIsometric Graph Paper3Lecture #2 EGR 110 – Engineering GraphicsIsometric Sketching (continued)•Note that lines that are parallel in the actual object will still be parallel.•Remember with circular features to use the "enclosing box" method. However, the "enclosing box" will be a parallelogram rather than a square and the hole or circular feature will appear as an ellipse.Circle is tangent to the midpointsof the “enclosing box”“enclosing box”circle“enclosing parallelogram”ellipseEllipse is tangent to the midpointsof the “enclosing parallelogram”Major axis of ellipseMinor axis of ellipse4Lecture #2 EGR 110 – Engineering GraphicsPossible steps in Isometric Sketching1. Form the "box" which contains the object using construction lines.2. Look for normal surfaces (parallel to the principle planes of the box). Normal surfaces are easiest to sketch first. All normal lines will be parallel to one of the three isometric axes.3. Fill in additional details (inclined planes, oblique planes, rounded edges, etc.)4. For holes or rounded features:a) Locate the "enclosing parallelogram"b) Sketch the major and minor axesc) Locate the midpoints for each side of the "enclosing parallelogram"d) Sketch the ellipse, making sure that it is tangent to each midpoint.e) The major axis of the ellipse is along the longest diagonal of the "enclosing parallelogram" and the minor axis is along the shortest diagonal.5Lecture #2 EGR 110 – Engineering GraphicsExample: Sketch an isometric drawing for the 3-view layout below (Problem A-5 in Engineering Graphics Workbook, Series 1).6Lecture #2 EGR 110 – Engineering GraphicsExample: Sketch an isometric drawing for the 3-view layout below (Problem A-7 in Engineering Graphics Workbook, Series 1).7Lecture #2 EGR 110 – Engineering GraphicsExample: Sketch an isometric drawing for the 3-view layout below.8Lecture #2 EGR 110 – Engineering GraphicsExample: Sketch an isometric drawing for the 2-view layout