with the right side parallel to the profile plane.The block is then drawn, using all six views ofmulti-view projection.By careful examination of figure 5-22, you willsee that the lines AB, AE, BD and BC and thesurfaces ABC, ABE, and BDE are oblique tothree regular planes of projection. The lines areforeshortened and the surfaces are not shown intheir true shape in any of the six normalviews.The first step in the drawing of any auxiliaryview is to draw the object in normal multi-viewprojection, as shown in figure 5-23. A minimumof two orthographic views is necessary. The spacebetween these views is generally greater thannormal. The reason for this will become apparent.Notice in figure 5-23, in the front view, that Ais the end point of line AE (top view) and C isthe end point of CD.The second step is to decide which line orsurface is to be shown in an auxiliary view andwhich orthographic view it will be projected from.The following facts must be considered whenrendering this decision:1. Front or rear auxiliary views are alwaysprojected from a side view.2. Right or left auxiliary views are alwaysprojected from a front view.3. An elevation auxiliary view is alwaysprojected from the top view.The third step is to select the auxiliary andreference planes. The auxiliary plane is simply aplane parallel to the desired line or linesrepresenting an edge view of the desired surface.In figure 5-24, the true length of line AB and thetrue shape of surface ABE are desired. A left sideauxiliary view is needed. The auxiliary plane isdrawn parallel to line AB in the front view. LineAB actually represents an edge view of surfaceABE. The reference plane (top view) representsan edge view of the orthographic view (front view)from which the auxiliary view will be projected.Therefore, when front, rear, or side auxiliaryviews are desired, the reference plane will alwaysbe in the top view. When elevation auxiliary viewsare drawn, the reference plane may be in any viewin which the top view is represented by a straightline. The reference plane in figure 5-24 is the edgeof the top view that represents the front view.Remember that, although these planes arerepresented by lines, they are actually planesrunning perpendicular to the views.Step four is to project and locate the pointsdescribing the desired line or surface. Drawthe projection lines from the orthographicview perpendicular to the auxiliary plane.Then take the distances from the reference plane,whether by scaling or with a compass. Thedistances are the perpendicular distances fromthe reference plane to the desired point. In figure5-24, the projection lines are drawn from pointsA, B, and C in the front view, perpendicular tothe auxiliary plane. The projection line frompoint A indicates the line on which point Ewill also be located. The projection line frompoint C designates the line of both C and D,and that from B locates B only. To transferthe appropriate distances, first, look for anypoints lying on the reference plane. Thesepoints will also lie on the auxiliary planewhere their projection lines intersect it (points Aand C). To locate points B, D, and E, measurethe perpendicular distances they are from thereference plane in the top view and transferthese distances along their respective projectionlines in the auxiliary view. The points areequidistant from both the reference and auxiliaryplanes. Therefore, any line parallel to thereference plane is also parallel to the auxiliaryplane and equidistant from it.The fifth step is to connect these points.When the total auxiliary view is drawn, it issometimes hard to discern which lines should beindicated as hidden lines. A rule to remember isas follows:Those points and lines lying furthest awayfrom the auxiliary plane in the orthographic viewbeing projected from are always beneath any pointor line that is closer. In figure 5-24, point C(representing line CD) in the front view is furtherfrom the auxiliary plane than any line or surfaceit will cross in the auxiliary view. Therefore, itwill appear as a hidden line.The final step is to label and dimension theauxiliary view. The labeling must include anadequate description. The term AUXILIARYmust be included along with the location of theview in relation to the normal orthographic views(LEFT SIDE AUXILIARY VIEW, REARELEVATION AUXILIARY VIEW, and soforth). Dimensions are given only to those linesappearing in their true length. In figure 5-24,only lines AB, AE, and BE on the auxiliary viewshould be dimensioned.5-15
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