Chapter 5Orthographic ProjectionSix Standard ViewsView Placement (3rd angle projection)Revolving an Object to Produce the Six Basic ViewsThe Glass Box MetaphorProjection of an ObjectSlide 8Unfolding the Glass boxThird Angle Projection:Glass Box MethodDEMOHidden LinesPrecedence of LinesExampleHands-On 4Slide 17Necessary Views3 Views - Most CommonTransferring DimensionsMitered SystemSlide 22Slide 23Mitered System cont’d.Slide 25Slide 26Dividers or ScaleSlide 28Also ReviewSlide 30Review Hidden LinesSurface IdentificationView IdentificationConfiguration RuleSlide 35Slide 36Slide 37Points, Lines & PlanesExerciseSlide 40Center LinesSlide 42Slide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50Find Location & Size of a Thru HoleFind Location and SizeSlide 53Slide 54Cylinders, Holes & ArcsChapter 5MultiviewSketching & ProjectionPrint handoutsSelect File, PrintEdit the following selections to read:Select the OK buttonOrthographic ProjectionA system of drawing views of an object using perpendicular projectors from the object to a plane of projection (I.e. paper)Six Standard Views Top, front, right side, left side, back and bottom–Front»Usually shows most detail»If applicable – should show object in operating condition (I.e. car)View Placement (3rd angle projection)Front view usually shows the most detailProjection LinesWhy must views be arranged so that they align?To make it possible for someone to interpret the drawing.Revolving an Object to Produce the Six Basic ViewsThe Glass Box MetaphorImagine that the object you are going to draw is positioned inside a glass box, so that the large flat surfaces of the object are parallel to the walls of the box.–2 horizontal planes –2 frontal planes –2 profile planesFrom each point on the object, imagine a ray, or projector perpendicular to the wall of the box forming the view of the object on that wall or projection plane.–2 horizontal planes (top and bottom views)–2 frontal planes (front and back views)–2 profile planes (right and left side views)Projection of an Object8Projection of an ObjectUnfolding the Glass boxFor Third Angle Projection (the method in the U.S.)Imagine that the walls of the box are hinged and unfold the views outward around the front view.This will give you the standard arrangement of views for 3rd Angle Projection which is used in the US, Canada, and some other countries.10Third Angle Projection:Symbol forthird angle projection shown on dwgFirst Angle Projection:Symbol forfirst angle projectionGlass Box Method12DEMOIf a point, line or plane is in one view, it must be in all the views.13Hidden Lines14Precedence of LinesWhen visible lines, hidden lines and center lines coincide remember:–Visible lines take precedence over hidden lines– Hidden lines take precedence over center lines, For example:Figure 5.3215ExampleDo Hands-On 3 together–Need»HB pencil»Engineering Calculation Paper»Model»Instructions (Sept. Schedule of Assignments in Angel)–Follow instructions»Remember specs for the border & title block are included in the Penn State Erie Graphics Standards and in Handouts folder in AngelLabel–Views – TOP, FRONT, etc.16Hands-On 4Instructions on the webChapter 5MultiviewSketching & ProjectionPart 2Necessary Views•A sketch or drawing should only contain the views needed to clearly and completely describe the object. Choose the views that show the shape most clearly, have the fewest hidden lines, and show the object in a usual, stable, or operating position. One view drawingof a shimOne view drawingof a connecting rod3 Views - Most CommonTopFront Right SideHFF PProjection LinesWidthDepthHeight45°DepthPlanes?Dimensions?Views?Three views necessary?Which view could be eliminated?Reference Line or Fold Line20Transferring DimensionsMitered SystemDividers or ScaleMitered System1. Determine spacing necessary between the front and right side views.a. For example, when dimensioning, more space is needed between the views.clear spaceThis will be the left edge of the right side viewMitered System2. Extend a projection line from the bottom edge of the top view and one from the left side of the right side view until they intersect.clear spaceLeft edge of the right side viewBottom edge of the top viewIntersectionMitered System3. Extend a 45° angled line from the point of intersection.From point of intersection45º2. Project additional points, surface by surface.Mitered System cont’d.11243133. Project additional points, surface by surface.Mitered System cont’d.243187654. Draw the view locating each vertex of the surface on the projection and miter line.Mitered System cont’d.24318765Dividers or Scale•With folding lines•Without folding lines28Hidden Lines29Also ReviewPENN STATE ERIE DRAFTING STANDARDSChapter 5MultiviewSketching & ProjectionPart 331Review Hidden Lines32Surface Identification33View Identification34Configuration RuleNORMAL SURFACEPlane is shown true shape and size. In other words, parallel to one of the principal planes.TSEDGEEDGESURFACE B35Configuration RuleEDGEEDGEINCLINDED SURFACESurface is perpendicular to one plane and will show as an edge on that plane.And the surface is tipped, or inclined, to adjacent planes. The surfaces in these views are foreshortened.36Configuration RuleOBLIQUE PLANE? PLANEEDGENORMAL PLANEEDGEEDGETSSurface is not parallel or perpendicular to any principal plane.37Configuration RuleIs this one correct?? PLANE38Points, Lines & PlanesIf all else fails, –Break the object down to simpler shapes–Locate the height, width and depth of each point.39ExerciseChapter 5MultiviewSketching & ProjectionPart 441Center Lines1/16” GAP1/8” DASH¾” – 1-1/2” LONGThin dark linePurpose of a center line?To show location of a hole, arc, cylinder, etc.42Center LinesExtend center line ¼” past the holeHOW MANY CENTER LINES MISTAKES? Extend center line ¼” past the hole43Center Lines¼” past the end of the hole and/or cylinderEnd of cylinderEnd of holeEnd of hole44Precedence of LinesHIDDEN LINES TAKE PRECEDENCE OVER CENTER LINESOBJECT LINES TAKE PRECEDENCE OVER HIDDEN LINES¼” FROM END OF HOLE1/16” GAP45Center Lines1/16” gapIf longer than 1-1/2” add a dash in the middleINCORRECT46Projection of an ObjectFillets and Rounds: Self locating, so do NOT add center lines, but do draw where sharp corner would be.47Projection of an ObjectPOOR PRACTICEPREFFEREDWhy?Adds clarity48Projection