Chapter 9 Multiview Drawings 203

202 Exploring Drafting Chapter 9 Multiview Drawings 203

Multiview 9 Drawings

OBJECTIVES Drafting vocabulary

After studying this chapter, Blocking in Orthographic you should be able to: Depth projection Engineering ◆ Understand the principles of Positive mass working drawings orthographic projection. Primary projection First-angle plane ◆ Use orthographic projection to develop projection Primary view multiview drawings. Foreshortening Principal planes ◆ Identify and explain projection planes Frontal plane Principal views and how they relate to multiview Height Proﬁ le plane drawings. Horizontal plane Third-angle ◆ Determine the views necessary to Mechanical drawing projection completely describe an object in a Multiview drawing True face multiview drawing. Negative mass Width Object feature ◆ Identify various types of features existing within objects. ◆ Identify and explain positive and negative mass as it relates to an object. ◆ Explain the difference between primary and secondary views of objects and features. ◆ Center a multiview drawing on the drawing sheet. 204 Exploring Drafting Chapter 9 Multiview Drawings 205

When a drawing is made with the aid of Top view Visualizing the Object and width, height, and depth) to be shown on a fl at instruments, it is called a mechanical drawing. surface having only two dimensions. The fl at Straight lines are made with a T-square, Left Rear view Projecting Views surface may be a piece of paper or the screen view triangle, or drafting machine straightedge. Before a drafter can generate the necessary of a computer monitor. Orthographic projec- Circles, arcs, and irregular curves are drawn views for a multiview drawing, he or she must tion is the key tool used in developing views with a compass, French curve, or the appro- be able to visualize the object being drawn. In for engineering working drawings (drawings priate template for the object needed. other words, the drafter must be able to see the used to manufacture or construct objects). As discussed in Chapter 7, drawings are Front Right There are two ways to project views in view view object in three dimensions in his or her mind’s also generated with computer-aided drafting Bottom eye. This is an essential skill in drafting. There orthographic projection, Figure 9-4. Third- (CAD) software. While many drafting fi rms view are many methods and techniques that aid in angle projection is preferred in the United now use CAD for developing drawing pro jects, the process of visualizing objects. The following States. First-angle projection is typically used knowledge of manual drafting techniques Figure 9-1 An object is normally viewed from six in most European countries. basic directions. approach should help the beginning drafter and procedures is still extremely valuable in become successful at visualizing objects. The difference between the two types solving design problems. To obtain the two-dimensional views of projection relates to the placement of the Regardless of the technique, whether needed for a multiview drawing, the drafter imaginary box in one of the quadrants formed traditional (manual) or CAD drafting, the than one two-dimensional view in order to should fi rst think of the object as being enclosed by the intersection of the three principal principles of drafting remain the same. The provide an accurate shape and size descrip- in a hinged glass box. See Figure 9-3. The planes. Referring to Figure 9-4, these planes drafter must be familiar with the standards tion of the object being produced. In devel- six surfaces of the glass box are the standard are the frontal plane, horizontal plane, and and procedures necessary to develop draw- oping the needed views, the object is normally projection planes to which the individual views profi le plane. The frontal plane represents the ings that accurately describe objects. viewed from six basic directions, as shown in are projected. The process used in projecting projection for the front view of an object. The Many drawings used by industry are Figure 9-1. These are the six principal views. the views to the projection planes is known as horizontal plane represents the projection for created as multiview drawings. A multiview They include the front, top, right side, left orthographic projection. This process allows the top view of the object. The profi le plane drawing is a drawing that requires more side, rear, and bottom views. See Figure 9-2. three-dimensional objects (objects having represents the projection for the side view of the object. In third-angle projection, the imaginary box containing the object rests in the third quadrant (the lower-right or third- angle quadrant when looking at the profi le plane). In this type of projection, the sides of Top view the object are projected to the sides of the box and toward the viewer. In fi rst-angle projection, the imaginary box containing the object rests in the fi rst quadrant (the upper-left or fi rst-angle quadrant when looking at the profi le plane). In this type of projection, the sides of the object are projected to the sides of Rear view Left view Front view Right view the box and away from the viewer. A graphic explanation of third-angle projection is shown in Figure 9-5. In this method, the object is viewed from points of view that are perpendicular to the projection planes (the surfaces of the glass box). The drafter looks Bottom view through the given projection plane and the surfaces, edges, and intersections that make Figure 9-2 The six basic directions of sight provide the principal views for developing a multiview drawing. Figure 9-3 Visualizing a three-dimensional object up the object are then projected forward to Shown are the principal views of the object in Figure 9-1. inside a hinged glass box helps establish the planes the projection plane. That is, the views are of projection for projecting views. projected to the six sides of the glass box. 206 Exploring Drafting Chapter 9 Multiview Drawings 207 hen unfolded hen unfolded

Frontal plane Second angle

First angle

Third angle

Horizontal Fourth plane angle

Profile plane

A Top Front First Bottom angle Third angle Third angle Left

Figure 9-4 Third-angle and fi rst-angle projection. A—The principal planes used in orthographic projection Rear Right divide the drawing space into four quadrants. B—An imaginary box containing the object is placed in the third are t The sides of the box In third-angle projection, the sides of the object are projected to the sides of the imaginary box. quadrant for third-angle projection. C—An imaginary box containing the object is placed in the fi rst quadrant for fi rst-angle projection. toward the viewer. toward Figure 9-5 208 Exploring Drafting Chapter 9 Multiview Drawings 209

Mechanical Engineer (continued) CAREERs in drafting and Air-Conditioning Engineers (www.ashrae. If I decide to pursue a different career, org) and the Society of Automotive Engineers what other fi elds are related to mechanical (www.sae.org), respectively. Special informa- engineering? Mathematics, drafting, archi- What are the special fi elds relating Mechanical Engineer tion for high school students about careers tecture, other types of engineering, and many to this career? Mechanical engineering is a in engineering is available from the Junior types of science. What would I do if I were to become a specialized fi eld of engineering. Specialized Engineering Technical Society (www.jets.org). mechanical engineer? I would design and fi elds of mechanical engineering include develop power-producing machines such as automotive design and plant engineering and generators, engines, and turbines. I would also maintenance. Mechanical engineering is also design and develop power-using machines related to the design of energy systems, manu- such as automotive vehicles, heating, venti- facturing systems, materials, pressure vessels lation, and air conditioning (HVAC) equip- and piping, and HVAC systems. Then, the “sides” of the glass box are unfolded so on. Compare the orientation of the views ment, machine tools, manufacturing systems What are my chances of finding a toward the drafter. The front is always the in Figure 9-5 to the orientation of the views and components, elevators and escalators, job? The demand for mechanical engi- featured view with the other views oriented in Figure 9-6. Notice that regardless of the and robots used in automation systems. I neers is not expected to grow quite as in the order obtained by unfolding the sides method of projection, all views are centered would also design and develop other types of fast as the demand for some other engi- of the box. In other words, the right side view about and originate from the front view. machinery and products. neering specialties over the next several What would I need to know? I would need is always to the right of the front view, the top Different symbols are used in industry to years. However, new technologies relating view is always above the front view, the bot- identify third-angle and fi rst-angle projection to know how to develop economical solutions to to nanotechnology, materials science, and tom view is always below the front view, and drawings. See Figure 9-7. The appropriate technical mechanical problems. I would have to biotechnology should provide opportuni- so on. know how to research, develop, design, manu- ties for mechanical engineers. Also, it is not symbol typically appears next to the title facture, and test tools, engines, machines, and uncommon for someone holding a degree in A graphic explanation of fi rst-angle block on the drawing sheet. other mechanical devices by applying theories mechanical engineering to qualify for jobs in projection is shown in Figure 9-6. In this and principles of math and science. Also, I other special engineering fields. method, the views are projected to the six Identifying Object Features would need to know basic drafting skills, stan- How much money could I expect sides of the box and the sides of the glass dards, and principles using both manual and to make? The median salary for degreed box are then unfolded away from the viewer. An object feature may be defi ned as a computer-aided drafting (CAD) techniques and mechanical engineers in recent years was When viewing the object from the front, the physical characteristic of an object. It may tools. All engineers need to be creative, inquisi- $74,920. However, salaries ranged from surfaces, edges, and intersections of the object be a hole that has been drilled, a notch that tive, analytical, and detail-oriented. $47,900 to $114,740 and up. Information from seen from that point of view are projected to a has been cut, or an angular cut. It is impor- Where would I work? Generally, I would a recent survey showed that mechanical engi- plane behind the object. In addition, the object tant for the drafter to be able to identify the work in an offi ce building, laboratory, or indus- neers with only a bachelor’s degree received is drawn as if the object were placed on each side features that exist in an object. This is because trial plant. offers averaging $48,585. With a master’s For whom would I work? I most often of the glass box. When viewing the object from the size and location of each feature must be degree, that fi gure increased to $54,565. With the top, what is seen is projected to a plane known for the object to be manufactured to would work in manufacturing. I would work for a doctorate, it was $69,904. below the object. When viewing the object the designer’s specifi cations. a manufacturer of machinery, transportation Where else could I look for more equipment, computer and electronics prod- information about becoming a mechan- from the bottom, what is seen is projected to a Features are physically represented as the ucts, or fabricated metal products. I may also ical engineer? See the US Department plane above the object. negative mass of an object. Let us say that all work for a government agency or a company of Labor’s Bureau of Labor Statistics A very easy way to identify a drawing objects begin as a solid mass of material. The in the architectural fi eld. Occupational Outlook Handbook (at www. that has been generated using fi rst-angle solid block has what can be termed positive What sort of education would I need? A bls.gov) or request information from the projection is to recognize that the views are in mass. Certain manufacturing operations must bachelor’s degree in mechanical engineering is American Society of Mechanical Engineers the opposite orientation of how they would be performed on the solid mass to create required. To be admitted to an undergraduate (www.asme.org). Information relating to two appear in third-angle projection. That is, the the object’s end product. These operations engineering school, courses are required in math special fields of mechanical engineering, views of the resulting multiview drawing are may include cutting, drilling, boring, and (through calculus), science (through physics), HVAC and automotive, is available from the oriented so that the top view appears where milling, among others. The important thing English, social studies, humanities, information American Society of Heating, Refrigerating, technology, and mechanical drafting/CAD. the bottom view should be, the bottom view to remember about these operations is that (continued) appears where the top view should be, and they all remove material (positive mass) from 210 Exploring Drafting Chapter 9 Multiview Drawings 211

Third-angle First-angle bending. This process does not remove mate- projection projection rial. However, the process of bending does create a feature in an object. There are other operations used to create features that do

hen unfolded hen unfolded not require removing material. Regardless of what operations are required to create an Figure 9-7 The appropriate symbol is placed object, a thorough understanding of positive on engineering drawings to show the method of and negative mass helps in identifying object projection used. features. Primary and the original solid mass. The resulting subtrac- Secondary Views tions created by these operations represent negative mass of the object. Hence, negative When creating multiview drawings, mass can be deﬁ ned as the areas of unoccu- every feature should be represented in every pied mass that exist within the overall limits view. If the feature is visible in the given view, of the original mass. See Figure 9-8. it is drawn with object lines. If the feature is For objects with more complex features, invisible in the given view, it is drawn with identifying the positive and negative mass hidden lines. Sometimes, in special situa- becomes more difﬁ cult. Objects made from tions, a feature may be partially visible and thin material, such as sheet metal, require partially invisible from a particular point of

Top view Top Front Bottom

Front view Side view

Object feature Right First angle Rear Left Negative mass Positive mass are t The sides of the box the sides of the object are projected to the sides of the imaginaryrst-angle projection, box. In ﬁ

Figure 9-8 The entire solid object in this multiview drawing represents positive mass. The hole, which is the only feature of the away from the viewer. The views are projected to the rear. The views from the viewer. away Figure 9-6 object, represents the negative mass of the object. 212 Exploring Drafting Chapter 9 Multiview Drawings 213 view. In such cases, the feature is drawn partly True Faces and the surface does not appear in its true shape with object lines and partly with hidden lines. when drawn on a two-dimensional surface. Nevertheless, all features are represented in Foreshortening For example, hole features on angled surfaces every view. When an object surface is drawn in its are not drawn in their true shape as circles The view in which the feature appears in its true shape and size within a view, it is said when projected. They are drawn as ellipses true shape and size is the primary view of the to be a true face. An object surface or feature because they are not perpendicular to the line feature. All other views then become secondary is drawn true size when it is parallel to the of sight. The resulting features are said to be views of the feature, Figure 9-9. The primary projection plane. Multiview drawings of foreshortened. view of a feature usually represents the feature planar objects are normally made up of views with object lines, except in more complex situ- representing true faces. Edges, Intersections, and ations. The secondary views usually represent Orthographic drawings use different Limiting Edges the feature with hidden lines. In dimensioning views to show the width, height, and depth multiview drawings, you will learn that, with of objects. These are the three most basic When creating multiview drawings, the few exceptions, the primary view is the view dimensions of any object. Width is deﬁ ned as visualization of objects can be simpliﬁ ed by in which the drafter will both locate and give the horizontal distance measured across an identifying what the lines in the different views the size of any given feature. Dimensioning is object from side to side. Height is the vertical should represent. In orthographic projection, discussed in Chapter 10. distance measured from the bottom to the top all lines on multiview drawings represent one The primary projection plane is the face of an object. Depth is the horizontal distance of three features of the object. Each line repre- of the glass box to which the primary view of measured from the front to the back of an Figure 9-10 Primary and secondary projection sents the edge view of a surface, an intersection a given feature is projected. The other faces object. planes. The primary view of a feature is projected between two surfaces, or the limiting edge then become the secondary projection planes in its true size and shape to the primary projection of a round or elliptical feature. See Figure 9- for that feature, Figure 9-10. plane. Secondary views are projected to secondary 13. Notice that most of the object features are projection planes. described in the primary view. The secondary Top view views use straight lines to show intersections

When a surface is drawn as a true face in a given view, the surface is seen as true height and true width (in the front or back view), Tr ue Secondary view Secondary faces (Not true shape) centerlines true height and true depth (in the right or left view), or true width and true depth (in the Front view Side view top or bottom view). See Figure 9-11. True Object feature faces do not have to be measured actual size. They may be drawn to scale. In other words, they may be drawn to a larger scale for easier Tr ue viewing or to a smaller scale to ﬁ t on the Tr ue faces face drawing media. Primary centerlines An object surface that is not parallel to the projection plane is not drawn as a true face in the resulting view. This type of surface is drawn smaller than true size and shape. This Primary view Secondary view (True shape and size) (Not true shape) is known as foreshortening and is common for objects with inclined surfaces. See Figure 9-9 Primary and secondary views. Object lines are used to represent Figure 9-12. Objects with inclined surfaces Figure 9-11 A surface that is parallel to the an object feature in its true size and shape in the primary view. Hidden lines are have at least one view where a face is at an projection plane is drawn as a true face (in its true used to represent the feature in the secondary view. angle to the projection plane. For this reason, shape and size). 214 Exploring Drafting Chapter 9 Multiview Drawings 215

Foreshortened length and edges. Thinking in these terms can help As shown in Figure 9-14B, the top view is in the visualization process as well as the placed above the front view, and the right view problem-solving process. is placed to the right. When drawing hidden lines in multiview drawings, it is also important to draw them Selecting Views correctly in relation to other types of lines. Top view to Be Drawn Hidden lines should always start and end with a dash in contact with the object line, Foreshortened surfaces As previously discussed, there are six Figure 9-16. This illustration shows examples standard views of any object in orthographic of how hidden lines are used and how they Tr ue projection. This does not mean that all six properly intersect or do not intersect other Length of the views must be used, or that they are lines, depending on the situation. Foreshortened length needed to completely describe an object. Only It is important to remember with any Inclined surface the number of views needed to give a complete drawing that the viewer wants to see as many (edge view) shape description of the object should be visible features as possible, not invisible drawn. Any view that repeats the same shape (hidden) features. The goal is to communicate description in another view (an identical view) the size and shape of the object as clearly and can be eliminated, Figure 9-14. precisely as possible to the person making In most instances, two or three views the part. Keep this in mind when laying out Side view Front view are sufﬁ cient to show the shape of an object. views for multiview drawings. Figure 9-12 Objects with inclined surfaces have at least one view where the surface is not parallel to the Objects that are basically cylindrical in shape projection plane. The inclined surface of this object does not appear in its true shape and size when projected can usually be drawn with just two views. to the top and side views. It instead appears foreshortened. The front view shows the inclined surface in its true Basic and complex prism-shaped objects length but does not show the surface’s true shape. To see the true shape and size of an inclined surface, you generally require at least three views. In Top view must draw an auxiliary view. Auxiliary views are discussed in Chapter 12. general, the front view should be the view that shows the most features (visible features) and the fewest hidden features of the object. Intersection The number of views needed is then decided Rear Left Front view Right Limiting edge in relation to the contents of the front view. view view view of cylinder In general, the drafter should draw the views that show the fewest features as hidden Unneeded Bottom view lines. These are the views that should be used views A Secondary view to create the multiview drawing. Views of objects showing a large number of hidden Surface edges lines are normally used only when absolutely necessary for the complete understanding of Top view the shape and size of the object. The use of too many hidden lines on a drawing tends to make Intersection the drawing confusing to the person reading the drawing or fabricating the part. Use Front view Right another view without as many hidden lines, view Figure 9-15. Sometimes it may be necessary to B draw the left side or bottom of an object if the Figure 9-14 Not all views are needed in a multiview features are visible from one of those points of drawing. Eliminate any view that repeats the same Primary view Secondary view view instead of the standard right side or top. shape description shown in another view. A—The six Regardless of the views shown, they should views of the object. B—Three views are sufﬁ cient for Figure 9-13 Lines in a multiview drawing represent edges of surfaces, intersections between surfaces, or still be placed in proper orthographic order. a complete description. limiting edges of round objects. 216 Exploring Drafting Chapter 9 Multiview Drawings 217

associated with it, the seven distances are each measured one time and then projected between the views. When projecting points, width measurements are projected between the front and top views. Height measurements are projected between the front and side views. See Figure 9-17. Depth distances are projected between the top and side views with a 45° projection angle or a compass, Figure 9-18. Of the two, the projection angle method is prob- Preferred Avoid ably more accurate than the compass method for most beginning drafters. However, if Figure 9-17 Projecting points from view to view. Figure 9-15 Views showing a large number of hidden lines are used only if absolutely necessary. Too many careful and precise compass placement and hidden lines tend to make the drawing confusing. adjustment is followed and the compass is kept properly sharpened, both methods work very effectively. efﬁ cient work are accuracy, neatness, and All projection lines are drawn as construc- speed. A drawing looks neater and more tion lines. If these lines are drawn correctly, professional if the views are evenly spaced they are very easily erased with a quality and centered on the drawing sheet. Centering eraser and erasing shield. Projection lines are the views on a sheet is not difﬁ cult if one of generally erased after all lines are darkened two basic methods is used. These methods to the proper line weights. Occasionally a are discussed in the following sections. drafting instructor may require the student to leave projection lines on a drawing to check Centering the Drawing with Lines meeting object lines Lines do not for proper usage. Construction Lines or other hidden lines meet or cross 1. Examine the object to be drawn. Observe Figure 9-16 Correct uses of hidden lines. Centering a Multiview its width, depth, and height dimensions, Drawing Figure 9-19. Determine the orientation in which the object will be drawn. Projecting Points The process of using orthographic projec- In previous chapters of this text, you 2. Measure the working area of the sheet tion in creating the views of a multiview have learned that the keys to high-quality, after drawing the border and title block. It and Edges drawing is known as blocking in the drawing. It is essential that the beginning drafter This process can save much time and elimi- learn to properly use orthographic projec- nate many measurement errors. A good rule tion to project points and create views in to follow when blocking in a drawing is to multiview drawings. Each view will show measure each distance one time, double-check ° a minimum of two dimensions. The front the measurement for accuracy, and project the 45 view will show the overall width and overall distance to the adjacent view. Do not “double- R1 measure” distances. In other words, if a R2 height, the side view will show the height ″ and depth, and so on. Also, any two views particular feature has a height of 1 , do not of an object will have at least one dimension measure that inch distance in the front view in common. For example, the front and side and then remeasure the same distance in the views will both have the overall height of the side view. Measure once and project. This rule object in common. should be followed for each measurement. If an object has seven different measurements Figure 9-18 Two accepted methods used to transfer the depth of the top view to the side view. 218 Exploring Drafting Chapter 9 Multiview Drawings 219

Divide this total by 2. The calculations are This centering method and the next 1 1 –" Depth 2 as follows: method discussed are intended for multi- ″ Width 5" Height of front view = 2-1/2 view drawings with three views. The calcu- Space between views = 1″ lations should be adjusted accordingly for Depth of top view = 1-1/2″ drawings with one view, two views, or more Total = 5″ than three views. Always leave at least 1″ Height of working area = 7″ of space between any two given views for Total height of views = –5″ dimensioning purposes. The spacing may 1– ″ 2 2 Total = 2 vary depending on the space available on the Divide 2″ by 2 = 1″ drawing sheet. However, regardless of the This is the distance measured up from spacing used, it should be the same between the lower border line to locate the starting all views. point for drawing. 8. Measure up 1″ from the lower border Centering the Drawing with a " Figure 9-19 When centering views for a drawing, Figure 9-20 Height The object used as an example for line. Draw a horizontal construction line Centering Rectangle ﬁ rst determine the basic dimensions of the object. centering views on a drawing sheet. through this point. 9. From this line, measure up the height of 1. First, determine the maximum overall size of the object being drawn. See Figure 9-25. ″ × ″ ″ the front view and mark a point. Mark a should measure 7 10 if you are using 5. Measure in 1-1/4 from the left border ″ You must know the maximum overall 1/2″ borders on a 8-1/2″ × 11″ drawing line. Draw a vertical construction line point for the 1 spacing that separates the sheet and the title block measures 1/2″. through this point. views. Mark one more point for the depth Refer to Chapter 5 on how to prepare a 6. From this line, measure over a distance of the top view. Draw construction lines through these points. See Figure 9-22. drawing sheet. equal to the width of the front view. Draw ° 3. Allow 1″ spacing between views. another vertical construction line. See 10. Use either the 45 angle method or the 4. To locate the front view, add the width of Figure 9-21. radius method to transfer the depth of the front view, 1″ spacing between views, 7. The same procedure is followed to center the top view to the right side of the object, and the depth of the right view. the views vertically. The height of the front Figure 9-23. Subtract this total from the horizontal view and the depth of the top view are 11. Draw in the right view. Use construction width of the working surface (10″). used. A 1″ space will separate the views. lines. Divide this total by 2. This will be the Add these distances together. Subtract the 12. Complete the drawing by going over the starting point for laying out the sheet sum from the vertical working space (7″). construction lines, Figure 9-24. Use the horizontally. correct weight for the type of line drawn. Use the erasing shield when erasing the Figure 9-23 The depth of the top view is projected Using the object shown in Figure 9-20, to the side view. for example, the calculations are as remaining construction lines. follows: Width of front view = 5″ Spacing between views = 1″ Depth of right view = 1-1/2″ Total = 7-1/2″ Width of working area = 10″ Total width of views = –7-1/2″ Total = 2-1/2″ Divide 2-1/2″ by 2 = 1-1/4″ This is the distance measured from the left border to locate the starting point Figure 9-21 Vertical construction lines are drawn to for drawing. locate the front view. Figure 9-22 The top view is located with Figure 9-24 Object lines are drawn to complete the construction lines. drawing. Construction lines may be erased. 220 Exploring Drafting Chapter 9 Multiview Drawings 221

width, height, and depth of the object. space of the layout. These dimensions are horizontal construction lines through the Determine the orientation in which the used to establish the width and height of two measured points to create the top and object will be drawn. a centering rectangle within the drawing bottom of the centering rectangle. 2. Using the format of your choice, draw the area. For this example, the rectangle 8. Erase the diagonal construction lines used border and title block on the sheet. This measures 7-1/2″ × 5″. The three views for locating the center of the drawing example uses an 8-1/2″ × 11″ drawing of the object will ﬁ t inside this rectangle. area. Also, erase the horizontal and sheet. After completing the drawing, the views vertical construction lines intersecting the 3. Draw construction lines from corner will be centered horizontally and verti- center. These lines are no longer needed to corner across the drawing area. See cally on the drawing sheet. and could be misidentiﬁ ed as part of the Figure 9-26. This locates the center of a 6. To draw the centering rectangle, divide object drawing. After erasing these lines, rectangle representing the drawing area. the width (7-1/2″) by 2. Mark points the centering rectangle can be used to 4. Lay out two construction lines, one hori- for this measurement (3-3/4″) from block in the views. zontal and one vertical, intersecting the the center point on each side along the 9. To complete the drawing, measure hori- center point of the drawing area. horizontal construction line. Draw two zontally from the lower-left corner of the 5. Add the width of the object (5″) to the vertical construction lines through the centering rectangle. Lay out the overall depth (1-1/2″) plus 1″ for the distance two measured points to create the sides width, the 1″ spacing between views, and between views to determine the hori- of the centering rectangle. the depth of the object. See Figure 9-27. zontal space needed for the layout. Then 7. In similar fashion, divide the height of Draw two vertical construction lines Figure 9-25 The object used as an example for add the height (2-1/2″) to the depth the centering rectangle (5″) by 2. Mark through the two measured points and centering views. (1-1/2″) plus 1″ to determine the vertical points for this measurement (2-1/2″) extending the full height of the centering from the center point on each side along rectangle. These are Lines A and B in the vertical construction line. Draw two Figure 9-27E.

Projection angle

Line C

Line A Line B

A B (Steps 1–3) (Step 4) E F (Steps 9–10) (Steps 11–12) Centering rectangle

C D (Steps 5–7) (Step 8) G H (Step 13) (Step 14) Figure 9-26 Laying out the centering rectangle for the drawing. Figure 9-27 Completing the multiview drawing. After blocking in the views, the object lines are darkened. 222 Exploring Drafting Chapter 9 Multiview Drawings 223

10. From the lower-left corner, measure verti- 12. Draw a construction line through the 8. A drawing that has views in the proper orthographic order shows the top view above the cally along the left edge of the centering intersection of the projection angle and _____ view. rectangle and lay out the overall height Line B. This line should also extend the 9. The process of using orthographic projection in creating the views of a multiview of the object. Draw a horizontal construc- entire distance across the centering rect- drawing is called ______the drawing. tion line through the measured point angle. 10. Identify two methods used to project depth distances between the top and side views in a extending the entire width of the centering 13. Measure and lay out the features of the multiview drawing. rectangle. This is Line C in Figure 9-27E. object. When projecting points, measure 11. Where Line A and Line C intersect, draw each distance one time only and project a 45° projection angle extending to the the distance to the adjacent view. Do not Outside Activities upper-right corner of the centering rect- double-measure features. angle. If the angle does not intersect these 14. Complete the drawing by darkening lines. 1. Collect objects for the class to create multiview drawings using manual instruments. points, check for incorrect measurements Use the correct weight for the type of line One object should require only two views; another object should require a three-view and adjust the layout as needed. drawn. Recommended methods for dark- drawing. Find other objects that require more than three views to give a complete shape ening lines are discussed in Chapter 5. description. 2. Build a hinged box out of clear plastic that can be used to demonstrate the “unfolding” of Creating Multiview Drawings in CAD the sides to show the front, top, bottom, and side views of an object. Place an object inside the box, trace the profi les of the object on the sides of the plastic with chalk or a marker, Multiview drawings showing 2D views are developed in CAD programs using drawing and then unfold the box to show the multiview projections. commands and layout methods similar to those involved in manual drafting. CAD commands 3. Make a large poster for your drafting room showing the step-by-step procedure for are introduced in Chapter 7. When using a CAD program to generate views, points are projected centering a drawing on a sheet using one of the two methods explained in this chapter. using construction lines, coordinate entry, and drawing aids such as orthogonal mode and snap. Object features in each view are drawn with basic drawing commands. Hidden features are drawn in the same manner using the hidden linetype. STEM Activities Some CAD programs provide the ability to create multiview drawings from 3D models. For example, it is common to orient several 2D orthographic views of a 3D drawing along with 1. Obtain a common workshop tool, such as a wrench or C-clamp. Using digital calipers, a pictorial view, such as an isometric view. CAD-based pictorial drawing and modeling func- practice making internal and external measurements of the tool. Make measurements in tions are discussed in more detail in Chapter 13. both inch and metric units. Once you are comfortable making measurements with the calipers, record the various measurements and make a multiview drawing of the tool. Use an appropriate drawing scale. Select the most appropriate view for the front view Test Your Knowledge and project other views as needed. 2. Select several objects in your drafting room. Select one that would require two views Please do not write in this book. Place your answers on another sheet of paper. to fully describe it, another that would require three views, and yet another that would 1. Name the six viewing directions that defi ne the principal views in a multiview drawing. require more than three views. Measure each object with the appropriate measuring tools 2. In orthographic projection, the _____ plane represents the projection for the top view of necessary to make measurements accurately. Select an appropriate drawing scale for each the object. object and create a multiview drawing of the object. 3. In the _____ method of orthographic projection, an imaginary glass box containing the object rests in the lower-right quadrant when looking at the profi le view. Drawing Problems 4. The view in which an object feature appears in its true shape and size is the _____ view of the feature. Draw the problems shown on the problem sheets on the following pages. Use the dimensions provided. Dimensions are in inches unless otherwise indicated. Follow the directions on each problem sheet. 5. Defi ne true face. 6. Objects that are drawn smaller than true size and shape in a view because they are not parallel to the projection plane are said to be _____. 7. When selecting object views to be drawn, why is it recommended to use the views showing the fewest features as hidden lines? 224 Exploring Drafting Chapter 9 Multiview Drawings 225

Complete this view Complete this view Complete this view

1 _1 1 _ 5 _1 2 5 1 2 1 1 3 2 _3 1 2 5 1 _ 2 _1 _ 5 2 _ _3 2 2 4 4 2 4

Complete this view _1 _1 1 2 2_1 2 2_ 2 2 2 2 1_1 _3 4 4

1. 2. 7. 8.

_3 Complete this view 4 1 _1 1 1 1 2 _ 1 1 _ 1 _ 5 1_1 1 _ 2 _3 2 4 4 _1 2 2 5 5 _3 1 2 _1 5 _1 _1 4 4 2 2 2 2

1 Complete Complete this view _1 Complete this view 1 _1 _1 2 2 _ 2 this view 2 2 2 2 2

1 1 1 _ _3 1_1 _ _3 3.4 4. 4 9. 4 10. 2 4

_3 Complete this view 4

_5 _5 _1 _1 _1 5 1 1 1 1 1 5 1_1 8 8 _1 4 2 4 _1 _1 _3 _3 2 5 1 5 1 2 _1 1 2 2 2 2 4 4 13_ 16 1 1 _1 ° 4 Complete this view _1 Complete this view _1 45 Complete 2 2 2 _1 2_1 2 2 2 _5 2 this view 8 13_ 1 16 _1 _3 1 _5 5. 4 4 ∅ 6. 11. 12. 8

Problem Sheet 9-1 Draw each problem on a separate sheet and complete as indicated. Problem Sheet 9-2 Draw each problem on a separate sheet and complete as indicated. 226 Exploring Drafting Chapter 9 Multiview Drawings 227

_1 _1 12 1 _1 2 4 1 1 4 4 Complete this view 2 _1 _3 _1 _3 2 1 1 _1 5 1 2 4 4 4 5 1 1 _ _1 2 2 _3 1_1 1_1 _3 4 4 4 4 4 1 12 _1 _1 2 2 1 _1 30° 1 2 2 Complete this view _1 1 2 2_1 1_ _1 2 2 19. 2 20. 21. 12 30°

1 3 3 _1 _1 _1 _ _ _ 1 1 3× ∅ 1 2 4 8 50.0 2 2 4 1 _1 13. 14. _1 5 5 60.0 25.0 2 2

_1 _1 22 25.0 22 _3 1 _1 35.0 4 2 _1 1 100.0 _1 2 2 _1 _1 _3 3 40.0 1 1 1 3 _ 2 2 1 _ 4 8 2 22. Dimensions are in MM 23. 24. 5 5 Dimensions are in MM 60° 1.5 40.0 Complete this view Complete _1 _1 _1 1 _3 4 2 ° 2 this view 125.0 2 2 45 2 ∅1 4 1 _1 60.0 _3 1 4 4 _1 22 ° _3 25.0 45 45° 15.4 16. 45° 25.0

2.75 R1.25 12.0 25. 26. 27. Complete this view 1_1 _3 2 4 R1 5 1 _1 _1 1_ 1 1 2 4 _1 _1 4 4 3 2 2 1 4 R1_ 2 2 5 8 R1 _1 ∅2 4 _1 _1 Complete _1 22 2 _1 2 22 2 2 this view 30° 30° 4 _1 12 1_1 ∅.75 THRU 17. 18. 4 28. 29. 30.

Problem Sheet 9-3 Draw each problem on a separate sheet and complete as indicated. Problem Sheet 9-4 Draw each problem on a separate sheet. Draw as many views as necessary to fully describe each problem. 228 Exploring Drafting Chapter 9 Multiview Drawings 229

∅ × ∅ PYRAMID APEX IS CENTERED .75 1_1 1.5 4 .312 2 2× ∅.75 ON BASE. R2.0 EQ SP 1 .75 _3 ∅4.75 3 3 1 .75 2.5 4 1 ∅4.25 .75 ∅ 1.75 1.0 2_1 2.5 2 1 1.5 1 .75 .75 1.5 ∅ 1 2.0 4 1 5 4_ ∅ 2 5 3.5 1.5 1.5 31. 32. 1.5 33. 43. 44. 1.5 45. ∅1.25

HEXAGON BASE = 3" ACROSS _1 _1 ∅1.00 _7 1 FLATS 1 8 2 2 1.00 ∅1 _3 _3 4 4 HEIGHT = 2" 4 .125 4 _1 1 APEX CENTERED ON BASE 2 .375 ∅ _ 2 2 ° _1 .625 7 45 2 _1 R _ 2 ° ∅ 1 2 16 _7 1 ° 60 .625 4 2_ 30 8 2 .625 _7 3 _1 8 _3 _3 ∅1.25 2 4 6.00 4 ° _1 15 4 1 _1 (TYP.) ∅1.00 2 2 1 ° 2 34. 35. 36. 15 46. 47. 48.

∅ ∅ ∅.625 _1 125.0 1.5 .75 1 25.0 THICK ∅ 2 1.5 DEEP 2× ∅.875 1 .25 R.75 4 ∅.625 ∅5.0 _1 1.5 2 .625 .375 .875 .5 ∅4.0 ∅3.0 _1 1 2 .5 1 .437 1 2 .25 2.5 2 ∅ R1.25 .5 .375 2 ∅20.0 ∅1.25 _3 1.5 _3 SMALL DIA = 3.0 ∅ 37. 4 4 38. 39. DIMENSIONS ARE IN MM 49. 50. 1.5 51. ∅ 3 ∅ .875 R ∅5.0 3× ∅.62 2.0 4" SPHERE ∅ 4× .312 4 EQ SP .875 ° 1 ∅ _7 45 1.0 R _1 ∅.437 1 _1 1 8 2 8 2 2 .75 1.0 R1 1 1 ∅ _1 4.5 2 1 1.0 2 3 1 3 2.5 1 4 1 ° 2 1 1 1 ∅3.0 45 1 2 1 1 3 _1 ∅ × ∅ 4 2× ∅ _ 1 3.0 ∅.75 THRU 1 4 .25 2 8 _3 2 1.75 EQ SP 40. 8 41. 42. 52. 53. 54.

Problem Sheet 9-5 Draw each problem on a separate sheet. Draw as many views as necessary to fully Problem Sheet 9-6 Draw each problem on a separate sheet. Draw as many views as necessary to fully describe each problem. describe each problem. 230 Exploring Drafting Chapter 9 Multiview Drawings 231

2 1 2 1 1 2 2 1 4 1

1 ∅ 4 3 1 1 ∅2 2 2 ∅4 ∅2 ∅1 1 1 2 2 2 1 1 2 1 1 2 4 1 2

1 ∅ 2X ∅1 1 4 4 2 ∅1 1 1 1 2 2 2 2

Problem 9-55 Draw as many views as necessary to fully describe the object. Problem 9-57 Draw as many views as necessary to fully describe the object.

1 ∅2 2 4 1 2 1 ∅1 2 1 ∅1 1 2X ∅ 2 2 1 1 2 2 4X ∅1 2X R1 4 ∅1 1 1 2 8 2 1 1 1 2 1 1 2 2 1 2 3 4 1 2 2 1 2 1 ∅ 1 1 1 1 4 2 4 4 1 2

Problem 9-56 Draw as many views as necessary to fully describe the object. Problem 9-58 Draw as many views as necessary to fully describe the object. 232 Exploring Drafting Chapter 9 Multiview Drawings 233

1 3 1 2 1 1 2 nd inserting title

1 2 1

1 1 2 4 1 4 1 2 1 2 1 1 2 2 1 1 1 1 2 1 2 2

Problem 9-59 Draw as many views as necessary to fully describe the object.

Design Problems

Design and prepare drawings for the following. A. Contemporary bookcase B. Bookends (any material) C. Stool D. Model drag racer E. Model boat (speed, sail, etc.) F. Workbench G. Table lamp H. Lawn or patio furniture

Problem 9-60 Complete each design problem. Draw as many views as necessary to fully describe When creating multiview drawings in a CAD program, there are special tools for arranging views, placing dimensions and notes, a placing dimensions and notes, views, arranging there are special tools for in a CAD program, drawings When creating multiview block information. Shown is a drawing included in the plans for a welding ﬁ xture model. (Autodesk, Inc.) (Autodesk, xture model. ﬁ a welding included in the plans for is a drawing Shown information. block the object.