8.30A-B Correct center lines for holes and slots.8.30CCenter lines should not terminate at another line or extend between views. Very short,unbroken center lines may be used to represent the axes of very small holes.8.30DCenter lines as bolt circles.8.30ECenter lines as paths of motion.CREATING MULTIVIEW DRAWINGS8.31Some objects can be adequately described with only one view.8.32Cylindrical, conical, and pyramidal objects can be described with two views8.33-38Creating three view drawings by traditional and CAD methods.8.39Before a multiview drawing can be created four basic decisions must be made.Determine the best position of the object.8.40Select the views that will show the least amount of hidden features.8.41Determine the front view which should show the object in its natural view or assembledstate, such as the front view of a car.8.42Determine the minimum number of views needed to describe the object.8.43Once the front view is selected, determine the other views needed to describe the objectwith the fewest number of lines.EDGE VIEWS8.44An edge, or corner, is the intersection of two planes, and is represented as a line on amultiview drawing. A normal edge, or true-length line, is an edge that is parallel to aplane of projection and thus perpendicular to the line of sight.
CHAPTER 8 Multiview Drawings858.45An inclinededge, or line, is parallel to a plane of projection, but inclined to theadjacent planes and appears foreshortened in the adjacent views. Features areforeshortened when the lines of sight are not perpendicular to the feature. An obliqueline is not parallel to any principal plane of projection, therefore, never appears in its truelength or point in any of the six principal views.NORMAL PLANES8.46A normal or principal planeis parallelto one of the principal planes of projection,and therefore is perpendicular to the line of sight.A frontal planeis parallel to the front plane of projection and is true shape and size inthe front and back views. (plane A)A horizontal planeis parallel to the horizontal plane of projection and is true shape andsize in the top and bottom views. (plane B)A profile planeis parallel to the profile plane of projection and is true shape and size inthe right and left views. (plane C)A inclined planeis perpendicular to one plane of projection (edge) and inclined toadjacent planes (foreshortened), and cannot be viewed in true size and shape in any ofthe principal views. (plane D)An oblique planeis oblique to all principal planes of projection. An oblique surfacedoes not appear in its true shape or size, or as a line in any of the principal views:instead, an oblique plane always appears foreshortened in any principal view.REPRESENTATIONS OF COMMON GEOMETRIC SHAPES8.47Multiview representations of common geometric shapes. A point represents a specificposition in space and has no width, height, or depth. A point can represent:The end view of a line.
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- Winter '17
- Orthographic Projection, Parallel projection, Graphical projections, Multiview Drawings