© Dr Simin Nasseri Southern Polytechnic State University 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 10 Image Slides Engineering Graphics I Dr Simin Nasseri Southern Polytechnic State University © Copyright 2010

© Dr Simin Nasseri Southern Polytechnic State University 2 OBJECTIVES After completing this chapter, the student will be able to: 1. Explain orthographic and multiview projection. 2. Identify frontal, horizontal, and profile planes. 3. Identify the six principal views and the three space dimensions. 4. Apply standard line practices to multiview drawings. 5. Create a multiview drawing using hand tools or CAD. 6. Identify normal, inclined, and oblique planes in multiview drawings. 7. Represent lines, curves, surfaces, holes, fillets, rounds, chamfers, runouts, ellipses, and space curves in multiview drawings. 8. Apply visualization by solids and surfaces to read multiview drawings. 9. Explain the importance of multiview drawings. 10. Identify limiting elements, hidden features, and intersection of two planes in multiview drawings.

© Dr Simin Nasseri Southern Polytechnic State University 3 Figure Multiview representations of common geometric shapes

© Dr Simin Nasseri Southern Polytechnic State University 4 Figure Surfaces that are parallel to the lines of sight will appear as edges

© Dr Simin Nasseri Southern Polytechnic State University 5 Figure Top views Front views Angles are true size when they are in a normal plane.

© Dr Simin Nasseri Southern Polytechnic State University 6 Figure 10.50

© Dr Simin Nasseri Southern Polytechnic State University 7 Figure Rounded ends or partial cylinders are represented in the circular view by arcs and by rectangles in the adjacent views. If the cylinder is tangent no change of plane is shown. This length is equal to the diameter

© Dr Simin Nasseri Southern Polytechnic State University 8 Figure If tangency does not exist then a line is used to represent the change of plane between the partial cylinder and the prism. This length is equal to the diameter

© Dr Simin Nasseri Southern Polytechnic State University 9 Figure An ellipse is used to represent a hole or circular feature that is viewed at an angle other than perpendicular or parallel.

© Dr Simin Nasseri Southern Polytechnic State University 10 Figure Minor diameter = D sin(30) Diameter D Minor diameter = D sin(45) Minor diameter = D sin(80)

© Dr Simin Nasseri Southern Polytechnic State University 11 Figure A through hole is a hole that goes all the way through an object, is represented in one view as two parallel hidden lines for the limiting elements, and is shown as a circle in the adjacent view. A blind hole is a hole that is not drilled all the way through the object. Counterbored holes are used to allow the heads of bolts to be flush or below the surface of the part.

© Dr Simin Nasseri Southern Polytechnic State University 12 Figure Countersunk holes are commonly used for flathead screws, and are represented by 45 degree lines. A spotface hole provides a place for heads of fasteners to rest by creating a smooth surface on cast parts. The representation of a threaded hole is shown. In all hole representations a line must be drawn to represent the change that occurs between the large and small diameter.

© Dr Simin Nasseri Southern Polytechnic State University 13 Figure A fillet is a rounded interior corner and a round is a rounded exterior corner normally found on a cast or forged part. When a surface is to machined to a finish, a finish mark in the form of a v is drawn on the edge view of the surface to be machined.

© Dr Simin Nasseri Southern Polytechnic State University 14 Figure A chamfer is a beveled corner used on the openings of holes and the ends of cylindrical parts, to eliminate sharp corners.

© Dr Simin Nasseri Southern Polytechnic State University 15 Figure Examples of filets and rounded corner.

© Dr Simin Nasseri Southern Polytechnic State University 16 Figure Finish mark symbols These marks are placed on engineering drawings to indicate machine finished surfaces.

© Dr Simin Nasseri Southern Polytechnic State University 17 Figure 10.60

© Dr Simin Nasseri Southern Polytechnic State University 18 Figure A runout is a special method of representing filleted surfaces that are tangent to cylinders.

© Dr Simin Nasseri Southern Polytechnic State University 19 Figure Examples of runouts in multiview drawings.

© Dr Simin Nasseri Southern Polytechnic State University 20 Figure Examples of runouts in multiview drawings.

© Dr Simin Nasseri Southern Polytechnic State University 21 Figure If a right cylinder is cut at an acute angle to the axis, an ellipse is created.

© Dr Simin Nasseri Southern Polytechnic State University 22 Figure Irregular or space curves are created by plotting points along the curve in one view, and then transferring or projecting the points into the adjacent views. Figure 10.65

© Dr Simin Nasseri Southern Polytechnic State University 23 Figure When two cylinders intersect a line of intersection is formed. Notice the change in diameter of the pink cylinder and the representing line of intersection.

© Dr Simin Nasseri Southern Polytechnic State University 24 Figure When cylinders intersect prisms: large prisms are represented using true projection, while small prisms are not.

© Dr Simin Nasseri Southern Polytechnic State University 25 Figure When cylinders intersect cylinders large holes or slots are represented using true projection, while small holes and slots are not.

© Dr Simin Nasseri Southern Polytechnic State University 26 Figure Examples of the standard representations of various geometric forms. Find different lines, surfaces, tangencies, holes, fillets, rounds, chamfers, runouts, ellipses, and space curves in these multiview drawings.

© Dr Simin Nasseri Southern Polytechnic State University 27 Examples of the standard representations of various geometric forms. Find different lines, surfaces, tangencies, holes, fillets, rounds, chamfers, runouts, ellipses, and space curves in these multiview drawings.

© Dr Simin Nasseri Southern Polytechnic State University 28 Figure Test yourself: Given the top view, make isometric sketches of possible 3-D objects.

© Dr Simin Nasseri Southern Polytechnic State University 29 Figure Here are possible solutions!

© Dr Simin Nasseri Southern Polytechnic State University 30 Figure When multiview drawings are created from a given pictorial view, surfaces can be labeled to check the accuracy of the solution.

© Dr Simin Nasseri Southern Polytechnic State University 31 Figure Missing line problems can be used to develop visualization. (you had an assignment on these)

© Dr Simin Nasseri Southern Polytechnic State University 32 Figure Vertices labeling can also be used to check the accuracy of multiview drawings.

© Dr Simin Nasseri Southern Polytechnic State University 33 Figure A partial view used on a symmetrical object. ANSI standards of multiview drawings form the common language used by engineers and technologists for communication information. A partial view shows only what is necessary to completely describe the object. A conventional break line is placed in a location where it does not coincide with a visible or hidden line.

© Dr Simin Nasseri Southern Polytechnic State University 34 Figure Revolution conventions used to simplify the representation of ribs and webs. ANSI revolution conventions allow geometry to be revolved into positions that allow an object to be viewed true size and shape.

© Dr Simin Nasseri Southern Polytechnic State University 35 Figure Revolution conventions used on objects with bolt circles to eliminate hidden lines and improve visualization.

© Dr Simin Nasseri Southern Polytechnic State University 36 Figure Inclined arms can also be revolved perpendicular to the line of sight to allow for better visualization of the object.

© Dr Simin Nasseri Southern Polytechnic State University 37 Figure A removed view may have to be created that is at a different scale and thus cannot be aligned with the existing views.