Chapter 8 Multiview Drawings - MHHE - McGraw Hill...

As lines, so loves oblique, may well

Themselves in every angle greet;

But ours, so truly parallel,

Though infinite, can never meet.

Andrew Marvell

375

Chapter

Multiview Drawings 8

OBJECTIVES

After completing this chapter, you 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 spacedimensions.

4. Apply standard line practices to multiview drawings.

5. Create a multiview drawing using hand tools orCAD.

6. Identify normal, inclined, and oblique planes inmultiview drawings.

7. Represent lines, curves, surfaces, holes, fillets,rounds, chamfers, runouts, and ellipses in multiviewdrawings.

8. Apply visualization by solids and surfaces tomultiview drawings.

9. Explain the importance of multiview drawings.

10. Identify limiting elements, hidden features, andintersections of two planes in multiview drawings.

INTRODUCTION

Chapter 8 introduces the theory, techniques, and standardsof multiview drawings, which are a standard method forrepresenting engineering designs. The chapter describeshow to create one-, two-, and three-view drawings withtraditional tools and CAD. Also described are standardpractices for representing edges, curves, holes, tangencies,and fillets and rounds. The foundation of multiview draw-ings is orthographic projection, based on parallel lines ofsight and mutually perpendicular views. �

8.1 PROJECTION THEORY

Engineering and technical graphics are dependent on pro-jection methods. The two projection methods primarilyused are perspective and parallel. (Figure 8.1) Both

methods are based on projection theory, which has takenmany years to evolve the rules used today.

Projection theory comprises the principles used torepresent graphically 3-D objects and structures on 2-D

Projections

Perspective or CentralProjections

Parallel Projections

The Attributes of Each Projection Method

Projection Method

Linear Perspective-One-Point-Two-Point-Three-Point

Oblique Projection-Cavalier-Cabinet-General

Orthographic ProjectionAxonometric

-Isometric-Dimetric-Trimetric

Multiview Projection-Third Angle

-First Angle

Lines ofSight

One principalplane parallel

to plane ofprojection

Application

(preferrred)

Converging;inclined toplane ofprojection

Parallel;normal toplane ofprojection

Parallel;inclined toplane ofprojection

Parallel;normal toplane ofprojection

Sometimes

Always

Never

For allprincipal

views

Single viewpictorial



Multiviewdrawings

OrthographicProjections

One-PointPerspective

Three-pointPerspective

Two-PointPerspective

CabinetProjection

CavalierProjection

GeneralProjection

Isometric

oq = or = oga = b = c

q

g

a

b

c

r

o

q

g

r

a

b

co

q

r

g

ab

co

Dimetric

Trimetric

oq ≠ or ≠ oga ≠ b ≠ c

MultiviewProjections

AxonometricProjections

First-angle projection

Third-angle projectionRSF

T

T

F RS

T

F

RS F

T

RS

LinearPerspectives

AerialPerspectives

ObliqueProjections

Aerial PerspectiveObject features appear

less focused at a distance

DepthVaries

FullDepth

HalfDepth

oq = or ≠ oga = b ≠ c

Figure 8.1 ProjectionMethodsProjection techniquesdeveloped along two lines:parallel and perspective.

CHAPTER 8 Multiview Drawings 377

media. An example of one of the methods developed toaccomplish this task is shown in Figure 8.2, which is apictorial drawing with shades and shadows to give theimpression of three dimensions.

All projection theory is based on two variables: line ofsight and plane of projection. These variables are de-scribed briefly in the following paragraphs.

8.1.1 Line of Sight (LOS)

Drawing more than one face of an object by rotating theobject relative to your line of sight helps in understandingthe 3-D form. (Figure 8.3) A line of sight (LOS) is animaginary ray of light between an observer’s eye and anobject. In perspective projection, all lines of sight start ata single point (Figure 8.4); in parallel projection, all linesof sight are parallel (Figure 8.5).

8.1.2 Plane of Projection

A plane of projection (i.e., an image or picture plane) isan imaginary flat plane upon which the image created bythe lines of sight is projected. The image is produced byconnecting the points where the lines of sight pierce theprojection plane. (See Figure 8.5.) In effect, the 3-D ob-ject is transformed into a 2-D representation (also calleda projection). The paper or computer screen on which asketch or drawing is created is a plane of projection.

Figure 8.2 Pictorial IllustrationThis is a computer-generated pictorial illustration with shadesand shadows. These rendering techniques help enhance the 3-Dquality of the image. (Courtesy of SDRC.)

ORTHOGRAPHIC

REVOLVED

TIPPED FORWARD

Orthographic

Revolved

Tipped forward

Paper(Plane of projection)

Parallel lines of sight

Figure 8.3 Changing ViewpointChanging the position of the object relative to the line of sight creates different views of the same object.

8.1.3 Parallel versus Perspective Projection

If the distance from the observer to the object is infinite(or essentially so), then the projectors (i.e., projectionlines) are parallel and the drawing is classified as a paral-lel projection. (See Figure 8.5.) Parallel projection

378 PART 2 Fundamentals of Technical Graphics

requires that the object be positioned at infinity andviewed from multiple points on an imaginary line paral-lel to the object. If the distance from the observer to theobject is finite, then the projectors are not parallel and thedrawing is classified as a perspective projection. (See

Picture plane

(paper or computer screen)

Nonparallel lines of sightradiating from a point

Observer (Station point)One viewpoint

View of object projected onto

picture plane

Figure 8.4 Perspective ProjectionRadiating lines of sight produce a perspective projection.

Parallel lines of sight

Observer (Station point)Infinite viewpoint

Picture plane

(paper or computer screen)

View of object projected onto

picture plane

Figure 8.5 Parallel ProjectionParallel lines of sight produce a parallel projection.


Figure 8.4.) Perspective projection requires that the ob-ject be positioned at a finite distance and viewed from asingle point (station point).

Perspective projections mimic what the human eyesees; however, perspective drawings are difficult to cre-ate. Parallel projections are less realistic, but they areeasier to draw. This chapter will focus on parallel projec-tion. Perspective drawings are covered in Chapter 10.

Orthographic projection is a parallel projectiontechnique in which the plane of projection is positionedbetween the observer and the object and is perpendicularto the parallel lines of sight. The orthographic projectiontechnique can produce either pictorial drawings that

show all three dimensions of an object in one view ormultiviews that show only two dimensions of an objectin a single view. (Figure 8.6)

8.2 MULTIVIEW PROJECTION PLANES

Multiview projection is an orthographic projection forwhich the object is behind the plane of projection, and theobject is oriented such that only two of its dimensions areshown. (Figure 8.7) As the parallel lines of sight piercethe projection plane, the features of the part are outlined.

Multiview drawings employ multiview projectiontechniques. In multiview drawings, generally three viewsof an object are drawn, and the features and dimensionsin each view accurately represent those of the object.Each view is a 2-D flat image, as shown in Figure 8.8.The views are defined according to the positions of theplanes of projection with respect to the object.

8.2.1 Frontal Plane of Projection

The front view of an object shows the width and heightdimensions. The views in Figures 8.7 and 8.8 are frontviews. The frontal plane of projection is the plane ontowhich the front view of a multiview drawing is projected.

Isometric MultiviewOblique

Figure 8.6 Parallel ProjectionParallel projection techniques can be used to create multiviewor pictorial drawings.

Plane ofprojection(frontal)

Projectors perpendicular toplane

(A)

Plane ofprojection(frontal)

Lines of sightperpendicular to planeof projection

Object’s depth is notrepresented

Frontview

(B)

Depth

Figure 8.7 Orthographic ProjectionOrthographic projection is used to create this front multiview drawing by projecting details onto a projection plane that is parallel tothe view of the object selected as the front.


Industry Application

CAD and Stereolithography Speed Solenoid Design

Source: “CAD and Stereolithography Speed Solenoid Design,” Machine Design, August 13, 1993, p. 80. Photos courtesy of Thomas J. Pellegatto, Senior DesignEngineer, Peter Paul Electronics Co. Inc., New Britain, CT 06050–1180.

When Peter Paul Electronics faced the need to quickly re-design a humidifier solenoid valve, Senior Design Engi-neer Thomas J. Pellegatto naturally turned his CAD-KEY-based system loose on the physical parameters of thenew valve. But that wasn’t enough. The design requiredlower-cost manufacturing technology as well as dimen-sional and mechanical design changes.

Existing valves from the company feature an all-steelsleeve, consisting of a flange nut, tube, and end stop, allof which are staked together for welding. A weld bead se-cures the end stop to the tube at the top edge and joinsthe tube and threaded portion of the flange nut at the bot-tom. Alignment of these components becomes critical be-

The three components created in plastic include theovermolded valve housing with integral bracket (red), thebobbin on which the coil is wound, and the valve body withwhich the solenoid valve is connected (blue).

Redesign and simplification of the solenoid valve coil andsleeve assembly (left) is easily compared with the coil-on-bobbin assembly. The extended and molded one-piecebobbin eliminates the use of two machined parts, two welds,and one quality operation while providing an improvedmagnetic circuit, reduced weight, and lower cost.

cause the sleeve sits inside the coil, which is the heart ofthe solenoid valve. In addition, a plunger that causes airor fluid to flow in the valve rises inside the sleeve.

According to Pellegatto, the simplest method for reducing cost and complexity of the critical sleeve assembly was to use the coil’s bobbin to replace thesleeve and house the plunger. Working directly with engi-neers at DuPont, designers selected a thermoplasticnamed Rynite to eliminate misalignment and the need forwelding the new assembly. The CAD system fed PeterPaul’s internal model shop with the data to develop bob-bin prototypes from the thermoplastic. In addition, de-signers decided to mold the formerly metallic mountingbracket as part of the plastic housing.

Once designs were finalized, Pellegatto sent the CADfile to a local stereolithography shop, which built demon-stration models using a 3D Systems unit. Two copieseach of three molded components—the bobbin, valvebody, and overmolded housing—were produced forabout $3,000. Finally, after sample parts were approvedby the customer, hard tooling was developed using re-vised CAD files. This venture into “desktop manufactur-ing” saved enormous amounts of design cycle time, ac-cording to Pellegatto. �


8.2.2 Horizontal Plane of Projection

The top view of an object shows the width and depth di-mensions. (Figure 8.9) The top view is projected onto thehorizontal plane of projection, which is a plane sus-pended above and parallel to the top of the object.

8.2.3 Profile Plane of Projection

The side view of an object shows the depth and height di-mensions. In multiview drawings, the right side view isthe standard side view used. The right side view is pro-jected onto the right profile plane of projection, whichis a plane that is parallel to the right side of the object.(Figure 8.10)

8.2.4 Orientation of Views from Projection Planes

The views projected onto the three planes are shown together in Figure 8.11. The top view is alwayspositioned above and aligned with the front view, and theright side view is always positioned to the right of andaligned with the front view, as shown in the figure.

8.3 ADVANTAGES OF MULTIVIEW DRAWINGS

In order to produce a new product, it is necessary toknow its true dimensions, and true dimensions are notadequately represented in most pictorial drawings. Toillustrate, the photograph in Figure 8.12 is a pictorialperspective image. The image distorts true distances,which are essential in manufacturing and construction.Figure 8.13 demonstrates how a perspective projectiondistorts measurements. Note that the two width dimen-sions in the front view of the block appear different inlength; equal distances do not appear equal on a per-spective drawing.

In the pictorial drawings in Figure 8.14, angles are alsodistorted. In the isometric view, right angles are notshown as 90 degrees. In the oblique view, only the frontsurfaces and surfaces parallel to the front surface showtrue right angles. In isometric drawings, circular holes ap-pear as ellipses; in oblique drawings, circles also appearas ellipses, except on the front plane and surfaces parallelto the front surface. Changing the position of the objectwill minimize the distortion of some surfaces, but not all.

Since engineering and technology depend on exactsize and shape descriptions for designs, the best approach

Width

Height

Figure 8.8 Single ViewA single view, in this case the front view, drawn on paper orcomputer screen makes the 3-D object appear 2-D; onedimension, in this case the depth dimension, cannot berepresented since it is perpendicular to the paper.

Top View

Top view

Plane of

projection

(horizontal)Line of

sight

Perpendicular to plane

Depth

Width

Figure 8.9 Top ViewA top view of the object is created by projecting onto the horizontal plane of projection.


R side view

Plane of projection

(profile)

Perpendicular to plane

Right side view

Line ofsight

Depth

Height

Figure 8.10 Profile ViewA right side view of the object is created byprojecting onto the profile plane of projection.

Top view

Front view Right side view

Figure 8.11 Multiview Drawing of an Object For this object three views are created: front, top, and rightside. The views are aligned so that common dimensions areshared between views.

Figure 8.12 Perspective ImageThe photograph shows the road in perspective, which is howcameras capture images. Notice how the telephone poles appearshorter and closer together off in the distance. (Photo courtesy of

Anna Anderson.)

Lines of sightFront

Lines of sightSide

WIDTH

HL

FrontWhat you see

SideWhat you see

1 2 3 4 5

1 2 3 40

SP

WIDTH

WIDTH

SP

1

2

Figure 8.13 Distorted DimensionsPerspective drawings distort true dimensions.


is to use the parallel projection technique called ortho-graphic projection to create views that show only two ofthe three dimensions (width, height, depth). If the objectis correctly positioned relative to the projection planes,the dimensions of features will be represented in true sizein one or more of the views. (Figure 8.15) Multiviewdrawings provide the most accurate description of three-dimensional objects and structures for engineering, man-ufacturing, and construction requirements.

In the computer world, 3-D models replace the multi-view drawing. These models are interpreted directly fromthe database, without the use of dimensioned drawings.(Figure 8.16) See Chapter 7.

8.4 THE SIX PRINCIPAL VIEWS

The plane of projection can be oriented to produce an in-finite number of views of an object. However, someviews are more important than others. These principalviews are the six mutually perpendicular views that areproduced by six mutually perpendicular planes of projec-tion. If you imagine suspending an object in a glass boxwith major surfaces of the object positioned so that theyare parallel to the sides of the box, the six sides of the

1

Right angle doesnot measure 90°

Oblique

23

4

3

2

1

4

Right angledoes notmeasure 90°Isometric

Figure 8.14 Distorted AnglesAngular dimensions are distorted on pictorial drawings.

Figure 8.16 CAD Data Used Directly by Machine ToolThis computer-numeric-control (CNC) machine tool caninterpret and process 3-D CAD data for use in manufacturing,to create dimensionally accurate parts. (Courtesy of Intergraph

Corporation.)

8

57

R 9.5ø 10

ø 14

11.1

R 7

3 X ø 5

3819

4

R 9.5

Figure 8.15 Multiview DrawingMultiview drawings produce true-size features, which can be used for dimensionally accurate representations.

box become projection planes showing the six views.(Figure 8.17) The six principal views are front, top, leftside, right side, bottom, and rear. To draw these views on2-D media, that is, a piece of paper or a computer moni-tor, imagine putting hinges on all sides of the front glassplane and on one edge of the left profile plane. Then cutalong all the other corners, and flatten out the box to cre-ate a six-view drawing, as shown in Figure 8.18.

The following descriptions are based on the X, Y,and Z coordinate system. In CAD, width can be as-signed the X axis, height assigned the Y axis, anddepth assigned the Z axis. This is not universally truefor all CAD systems but is used as a standard in thistext. CAD Reference 8.1

The front view is the one that shows the most fea-tures or characteristics. All other views are based onthe orientation chosen for the front view. Also, allother views, except the rear view, are formed by rotat-


ing the lines of sight 90 degrees in an appropriate di-rection from the front view. With CAD, the front viewis the one created by looking down the Z axis (in thenegative Z viewing direction), perpendicular to the Xand Y axes.

The top view shows what becomes the top of the ob-ject once the position of the front view is established.With CAD, the top view is created by looking down theY axis (in the negative Y viewing direction), perpendicu-lar to the Z and X axes.

The right side view shows what becomes the rightside of the object once the position of the front view isestablished. With CAD, the right side view is created bylooking down the X axis from the right (in the negative Xviewing direction), perpendicular to the Z and Y axes.

The left side view shows what becomes the left sideof the object once the position of the front view is estab-lished. The left side view is a mirror image of the right

FRONTAL PLANE

RIGHT SIDE VIEW

PROFILE PLANE

HORIZONTAL PLANE

TOP VIEW

FRONT VIEW

H

F

F P

DEPTH

WIDTH

HEIGHT

Observer atinfinity

Multiple parallellines of sight

Figure 8.17 Object Suspended in a Glass Box, Producing the Six Principal ViewsEach view is perpendicular to and aligned with the adjacent views.


Frontal plane

R side view

Profile plane

Horizontal plane

Front view

F

F P DEPTH

WIDTH

HEIGHT

Top viewH

FP

Top

WIDTH

DEPTH

DEPTHDEPTH

L sideRear

Bottom

R sideF

H

H

F

PFFPPF

Front

EQUAL EQUAL

DEPTH

Y

X

Y

Z

Y

X

Y

Z

HEIGHT

WIDTH

Z

X

Z

X

Figure 8.18 Unfolding the Glass Box to Produce a Six-View Drawing

side view, except that hidden lines may be different.With CAD, the left side view is created by looking downthe X axis from the left (in the positive X viewing direc-tion), perpendicular to the Z and X axes.

The rear view shows what becomes the rear of theobject once the front view is established. The rear view isat 90 degrees to the left side view and is a mirror imageof the front view, except that hidden lines may be differ-ent. With CAD, the rear view is created by looking downthe Z axis from behind the object (in the positive Z view-ing direction), perpendicular to the Y and X axes.

The bottom view shows what becomes the bottom ofthe object once the front view is established. The bottomview is a mirror image of the top view, except that hid-den lines may be different. With CAD, the bottom viewis created by looking down the Y axis from below the ob-ject (positive Y viewing direction), perpendicular to theZ and X axes.

The concept of laying the views flat by “unfolding theglass box,” as shown in Figure 8.18, forms the basis fortwo important multiview drawing standards:

1. Alignment of views.

2. Fold lines.

The top, front, and bottom views are all aligned verticallyand share the same width dimension. The rear, left side,front, and right side views are all aligned horizontallyand share the same height dimension.

Fold lines are the imaginary hinged edges of the glassbox. The fold line between the top and front views is la-beled H/F, for horizontal/frontal projection planes; thefold line between the front and each profile view is la-beled F/P, for frontal/horizontal projection planes. Thedistance from a point in a side view to the F/P fold line isthe same as the distance from the corresponding point inthe top view to the H/F fold line. Conceptually, then, thefold lines are edge-on views of reference planes. Nor-mally, fold lines or reference planes are not shown in en-gineering drawings. However, they are very importantfor auxiliary views and spatial geometry construction,covered in Chapters 11 and 12. CAD Reference 8.2


Practice Exercise 8.1Hold an object at arm’s length or lay it on a flat surface.Close one eye, then view the object such that your line ofsight is perpendicular to a major feature, such as a flat side.Concentrate on the outside edges of the object and sketchwhat you see. Move your line of sight 90 degrees, or rotatethe object 90 degrees, and sketch what you see. Thisprocess will show you the basic procedure necessary to cre-ate the six principal views.

8.4.1 Conventional View Placement

The three-view multiview drawing is the standard used inengineering and technology, because many times theother three principal views are mirror images and do notadd to the knowledge about the object. The standardviews used in a three-view drawing are the top, front, andright side views, arranged as shown in Figure 8.19. Thewidth dimensions are aligned between the front and topviews, using vertical projection lines. The height dimen-sions are aligned between the front and profile views,using horizontal projection lines. Because of the relativepositioning of the three views, the depth dimension can-not be aligned using projection lines. Instead, the depthdimension is measured in either the top or right side viewand transferred to the other view, using either a scale,miter line, compass, or dividers. (Figure 8.20)

The arrangement of the views may only vary asshown in Figure 8.21. The right side view can be placedadjacent to the top view because both views share thedepth dimension. Note that the side view is rotated sothat the depth dimension in the two views is aligned.

8.4.2 First- and Third-Angle Projection

Figure 8.22A shows the standard arrangement of all sixviews of an object, as practiced in the United States andCanada. The ANSI standard third-angle symbol shownin the figure commonly appears on technical drawingsto denote that the drawing was done following third-angle projection conventions. Europe uses the first-angle projection and a different symbol, as shown in


Figure 8.22B. To understand the difference betweenfirst- and third-angle projection, refer to Figure 8.23,which shows the orthogonal planes. Orthographic pro-jection can be described using these planes. If the firstquadrant is used for a multiview drawing, the resultswill be very different from those of the third quadrant.

(Figure 8.24) Familiarity with both first- and third-angle projection is valuable because of the global natureof business in our era. As an example, Figure 8.25shows an engineering drawing produced in the UnitedStates for a German-owned company, using first-angleprojection.

(A) Scale (B) Dividers (C) Miter Line

0 1

01

MITER LINE

45°

Figure 8.20 Transferring Depth Dimensions from the Top View to the Right Side View, Using Dividers, a Scale, or a45-Degree Triangle and a Miter Line

Central view

Related views

RIGHT SIDE

FRONT

TOP

DEPTHProjection line

Figure 8.21 Alternate View ArrangementIn this view arrangement, the top view is considered the centralview.

WIDTH(X)

DEPTH(Z)

HEIGHT(Y)

Projection line

DEPTH(Z)

Multiple parallelprojectors

Figure 8.19 Three Space DimensionsThe three space dimensions are width, height, and depth. Asingle view on a multiview drawing will only reveal two of thethree space dimensions. The 3-D CAD systems use X, Y, and Zto represent the three dimensions.


BOTTOM

RIGHT FRONT LEFT

TOP

REAR

(B) European Standard

(A) U.S. Standard

LEFT

BOTTOM

RIGHTFRONT

TOP

REAR

Figure 8.22 Standard Arrangement of the Six Principal Views for Third- and First-Angle ProjectionThird- and first-angle drawings are designated by the standard symbol shown in the lower right corner of parts (A) and (B). Thesymbol represents how the front and right-side views of a truncated cone would appear in each standard.


8.4.3 Adjacent Views

Adjacent views are two orthographic views placed nextto each other such that the dimension they share in com-mon is aligned, using parallel projectors. The top andfront views share the width dimension; therefore, the topview is placed directly above the front view, and verticalparallel projectors are used to ensure alignment of theshared width dimension. The right side and front viewsshare the height dimension; therefore, the right side viewis placed directly to the right of the front view, and hori-zontal parallel projectors are used to ensure alignment ofthe shared height dimension.

The manner in which adjacent views are positionedillustrates the first rule of orthographic projection:Every point or feature in one view must be aligned on aparallel projector in any adjacent view. In Figure 8.26,

the hole in the block is an example of a feature shownin one view and aligned on parallel projectors in the ad-jacent view.

Principles of Orthographic Projection Rule 1:Alignment of FeaturesEvery point or feature in one view must be aligned on aparallel projector in any adjacent view.

The distance between the views is not fixed, and it canvary according to the space available on the paper andthe number of dimensions to be shown.

8.4.4 Related Views

Two views that are adjacent to the same view are calledrelated views; in related views, distances between com-mon features are equal. In Figure 8.26, for example, thedistance between surface 1 and surface 2 is the same inthe top view as it is in the right side view; therefore, thetop and right side views are related views. The front andright side views in the figure are also related views, rela-tive to the top view.

Principles of Orthographic Projection Rule 2:Distances in Related ViewsDistances between any two points of a feature in related viewsmust be equal.

8.4.5 Central View

The view from which adjacent views are aligned is thecentral view. In Figure 8.26, the front view is the centralview. In Figure 8.21, the top view is the central view.Distances and features are projected or measured fromthe central view to the adjacent views.

8.4.6 Line Conventions

The alphabet of lines is discussed in detail in Chapter3, Section 3.4, and illustrated in Figure 8.27. The tech-niques for drawing lines are described in detail in Sec-tion 3.5.

Because hidden lines and center lines are critical ele-ments in multiview drawings, they are briefly discussedagain in the following sections. CAD Reference 8.3

PROFILE PLANE

PROFILE PLANE

HORIZONTAL PLANE

SECONDQUADRANT

THIRDQUADRANT

FOURTHQUADRANT

FIRSTQUADRANT

FRONTAL PLANE

Figure 8.23 The Principal Projection Planes andQuadrants Used to Create First- and Third-AngleProjection DrawingsThese planes are used to create the six principal views of first-and third-angle projection drawings.


(A) Third-Angle Projection (B) First-Angle Projection

First-Angle Projection( Europe )

2nd1st3rd4th

HORIZONTAL PLANE

FRONTAL PLANE

RIGHT PROFILEPLANE

Third-Angle Projection( U.S. )

FRONTAL PLANE

RIGHT PROFILEPLANE

HORIZONTAL PLANE

FRONT VIEW

TOP VIEW

RIGHT SIDEVIEW

FRONT VIEW

TOP VIEW

RIGHT SIDE

VIEW

Figure 8.24 Pictorial Comparison between First- and Third-Angle Projection TechniquesPlacing the object in the third quadrant puts the projection planes between the viewer and the object. When placed in the firstquadrant, the object is between the viewer and the projection planes.

Figure 8.25 First-Angle ProjectionEngineering Drawing Produced in the UnitedStates for a European Company(Courtesy of Buehler Products, Inc.)

Verticalparallel

projectors

Central view Horizontalparallel

projectors

Related views

Equal

RIGHT SIDEFRONT

TOP

2

1 1

2

1

2

Figure 8.26 Alignment of ViewsThree-view drawings are aligned horizontally and vertically onengineering drawings. In this view arrangement, the front viewis the central view. Also notice that surfaces 1 and 2 are thesame distance apart in the related views: top and right side.

Hidden Lines In multiview drawings, hidden featuresare represented as dashed lines, using ANSI standard linetypes. (See Figure 8.27)

Dashed lines are used to represent such hidden fea-tures as:

Holes—to locate the limiting elements.Surfaces—to locate the edge view of the surface.Change of planes—to locate the position of thechange of plane or corner.

For example, Figure 8.28 shows dashed lines repre-senting hidden features in the front and top views. The


dashed parallel lines in the top and front views representthe limiting elements of the hole drilled through the ob-ject but not visible in these views. The hole is visible inthe right side view. The single vertical dashed line in thefront view represents the hidden edge view of surface C.Surface C is visible in the side view and is on edge in thetop and front views.

Most CAD systems may not follow a standard prac-tice for representing hidden lines. The user must decide ifthe drawn hidden lines effectively communicate the de-sired information. CAD Reference 8.4

VISIBLE LINE .6 mm

HIDDEN (DASHED) LINE .3 mm

CENTER LINE.3 mm

DIMENSION & EXTENSION LINES

1.25 .3 mm

PHANTOM LINE.3 mm

CUTTING PLANE LINES

.6 mm

CONSTRUCTION LINE.3 mm

SECTION LINES

.3 mm

2

2

Construction line

Hidden (dashed) line

Center line

Visible line

Cutting plane line

Extension line

Dimension line

.6 mm

Figure 8.27 Alphabet of LinesANSI standard lines used on technical drawings are of a specific type and thickness.


Center Lines Center lines are alternating long andshort thin dashes and are used for the axes of symmetri-cal parts and features, such as cylinders and drilledholes (Figure 8.29), for bolt circles (Figure 8.30D), andfor paths of motion (Figure 8.30E). Center lines shouldnot terminate at another line or extend between views(Figure 8.30C). Very short, unbroken center lines maybe used to represent the axes of very small holes (Fig-ure 8.30C).

Some CAD systems have difficulty representing cen-ter lines using standard practices. This is especially trueof the center lines for circles. Other CAD systems auto-matically draw the center lines to standards. CADReference 8.5

One- and Two-View Drawings Some objects can be ade-quately described with only one view. (Figure 8.31) Asphere can be drawn with one view because all viewswill be a circle. A cylinder or cube can be describedwith one view if a note is added to describe the missingfeature or dimension. Other applications include a thingasket or a printed circuit board. One-view drawings areused in electrical, civil, and construction engineering.

CAD Reference 8.6Other objects can be adequately described with

two views. Cylindrical, conical, and pyramidal shapes

are examples of such objects. For example, a cone can be described with a front and a top view. A profile view would be the same as the front view. (Figure8.32) CAD Reference 8.7

Three-View Drawings The majority of objects requirethree views to completely describe the objects. The fol-lowing steps describe the basics for setting up and devel-oping a three-view multiview drawing of a simple part.

Creating a Three-View Drawing

Step 1. In Figure 8.33, the isometric view of the part repre-sents the part in its natural position; it appears to be rest-ing on its largest surface area. The front, right side, andtop views are selected such that the fewest hidden lineswould appear on the views.

Step 2. The spacing of the views is determined by the totalwidth, height, and depth of the object. Views are carefullyspaced to center the drawing within the working area ofthe drawing sheet. Also, the distance between views canvary, but enough space should be left so that dimensionscan be placed between the views. A good rule of thumbis to allow about 1.5′′ (36 mm) between views. For thisexample, use an object with a width of 4′′, height of 3′′,and a depth of 3′′. To determine the total amount ofspace necessary to draw the front and side views in

SURFACEC

1

CA

CB

C

Figure 8.28 Hidden FeaturesThe dashed lines on this drawing indicate hidden features. Thevertical dashed line in the front view shows the location ofplane C. The horizontal dashed lines in the front and top viewsshow the location of the hole.

Small dashescross at thecenter

Extends pastedge of object8mm or 3/8"

Figure 8.29 Center LinesCenter lines are used for symmetrical objects, such ascylinders. Center lines should extend past the edge of theobject by 8 mm or c′′.


PATH OF MOTION

(E)

SPACE

CENTER LINE INLONGITUDINALVIEW FOR HOLES

(A) (B)

NO SPACE

SPACE

BOLT CIRCLE

(C) (D)

TOO SMALL TOBREAK THECENTER LINE

SPACE

Figure 8.30 Standard Center Line Drawing Practices for Various Applications


PC BoardBushing Sphere Plot PlanWasher

THK

O.D. I.D. O.D. I.D.

LENGTH DIAMETER

WIDTH

LENGTH

THICKNESS=X.X

Figure 8.31 One-View DrawingsApplications for one-view drawings include some simple cylindrical shapes, spheres, thin parts, and map drawings.

Cylindrical parts Cams

Conical parts

Hø

I.D.O.D.

L

R1

R2

R3

ø1

W

W1

W2

ø1

Figure 8.32 Two-View DrawingsApplications for two-view drawings include cylindrical and conical shapes.

alignment, add the width (4′′) of the front view and thedepth (3′′) of the side view. Then add 1.5′′ to give 8.5′′ asthe total amount of space needed for the front and sideviews and the space between. If the horizontal space onthe paper is 10′′, subtract 8.5′′ to get 1.5′′; divide the re-sult by 2 to get 0.75′′, which is the space left on eitherside of the two views together. These distances aremarked across the paper, as shown in Figure 8.34A.

In a similar manner, the vertical positioning is deter-mined by adding the height of the front view (3′′) to the depth of the top view (3′′) and then adding 1.5′′ for the space between the views. The result is7.5′′. The 7.5′′ is subtracted from the working area of9′′; the result is divided by 2 to get 0.75′′, which is thedistance across the top and bottom of the sheet. (Fig-ure 8.34B)

Step 3. Using techniques described previously in this text,locate the center lines in each view, and lightly draw thearc and circles. (Figure 8.34C)

Step 4. Locate other details, and lightly draw horizontal,vertical, and inclined lines in each view. Normally, thefront view is constructed first because it has the most de-tails. These details are then projected to the other views


using construction lines. Details that cannot be projecteddirectly must be measured and transferred or projectedusing a miter line. For example, dividers can be used tomeasure and transfer details from the top view to theright side view. (Figure 8.34D) A miter line can also beconstructed by drawing a 45-degree line from the inter-section of the top and side view and drawing the projec-tion lines as shown in Figure 8.34C.

Step 5. Locate and lightly draw hidden lines in each view.For this example, hidden lines are used to represent thelimiting elements of the holes.

Step 6. Following the alphabet of lines, darken all objectlines by doing all horizontal, then all vertical, and finallyall inclined lines, in that order. Darken all hidden andcenter lines. Lighten or erase any construction lines thatcan be easily seen when the drawing is held at arm’slength. The same basic procedures can be used with 2-DCAD. However, construction lines do not have to beerased. Instead, they can be placed on a separate layer,then turned off. CAD Reference 8.8

8.4.7 Multiviews from 3-D CAD Models

The computer screen can be used as a projection planedisplaying the 2-D image of a 3-D CAD model. The usercan control the line of sight and the type of projection(parallel or perspective). Most 3-D CAD software pro-grams have automated the task of creating multiviewdrawings from 3-D models. With these CAD systems,the 3-D model of the object is created first. (See Figure8.33.) Most CAD programs have predefined viewpointsthat correspond to the six principal views. (Figure 8.35)The views that will best represent the object in multivieware selected, the viewpoint is changed, a CAD commandconverts the projection of the 3-D model into a 2-Ddrawing, and the first view is created. (Figure 8.36) Thisview is then saved as a block or symbol. The secondview is created by changing the viewpoint again and thenconverting the new projection to a 2-D drawing of theobject. (Figure 8.37) These steps are repeated for asmany views as are necessary for the multiview drawing.

After the required number of 2-D views are created,the views are arranged on a new drawing by retrievingthe blocks or symbols created earlier. Care must be taken

RIGHTSIDE

TOP

FRONT

Figure 8.33 Selecting the Views for a Multiview DrawingThe object should be oriented in its natural position, and viewschosen should best describe the features.


10.00.75 4.00 1.50 3.00

TOPVIEW

FRONTVIEW

RIGHT SIDEVIEW

.75

3.00

1.50

9.00

3.00

Dividers used to transferdepth dimensionsbetween the top and rightside views

(A) (B)

(C) (D)

MiterLine

Figure 8.34 Steps to Center and Create a Three-View Multiview Drawing on an A-Size Sheet


Figure 8.35 Predefined Multiviews on a CAD System

399

TITLE:

DRAWING NO.: DATE:

DRAWN BY:

SHEET OF

REVISIONS

Figure 8.37 Changing the Viewpoint on the 3-D Model to Create a Right Side ViewThis view is captured, then placed in a title block and border line.

TITLE:

DRAWING NO.: DATE:

DRAWN BY:

SHEET OF

REVISIONS

Figure 8.36 Changing the Viewpoint on a 3-D CAD Model to Create a Front ViewThis view is captured, then placed in a title block and border line.

to bring the views in at the proper scale and correct align-ment. The views must then be edited to change solidlines to hidden lines and to add center lines. Otherchanges may be required so that the views are drawn toaccepted standards. (Figure 8.38) CAD Reference 8.9

8.5 VIEW SELECTION

Before a multiview drawing is created, the views must beselected. Four basic decisions must be made to determinethe best views:

1. Determine the best position of the object. The ob-ject must be positioned within the imaginary glassbox such that the surfaces of major features are ei-ther perpendicular or parallel to the glass planes.


(Figure 8.39) This will create views with a mini-mum number of hidden lines. Figure 8.40 showsan example of poor positioning: the surfaces ofthe object are not parallel to the glass planes, re-sulting in many more hidden lines.

2. Define the front view. The front view shouldshow the object in its natural or assembled stateand be the most descriptive view. (Figure 8.41)For example, the front view of an automobilewould show the automobile in its natural position,on its wheels.

3. Determine the minimum number of views neededto completely describe the object so it can be pro-duced. For our example, three views are requiredto completely describe the object. (Figure 8.42)

4. Once the front view is selected, determinewhich other views will have the fewest number

TITLE:

DRAWING NO.: DATE:

DRAWN BY:

SHEET OF

REVISIONS

Figure 8.38 Creating a Multiview Drawing of the 3-D ModelThe previously captured views are brought together with a standard border and title block to create the final drawing.

401

FRONTAL PLANE

RIGHT SIDE

VIEW

PROFILE PLANE

HORIZONTAL PLANETOP VIEW

FRONT VIEW

Figure 8.39 Good OrientationSuspend the object in the glass box such that major surfaces are parallel or perpendicular to the sides of the box (projection planes).

FRONTAL PLANE

RIGHT SIDE

VIEW

PROFILE PLANE


FRONT VIEW

No!

Figure 8.40 Poor OrientationSuspending the object in the glass box such that surfaces are not parallel to the sides produces views with many hidden lines.


of hidden lines. In Figure 8.43, the right sideview is selected over the left side view becauseit has fewer hidden lines.

Practice Exercise 8.2Using any of the objects in Figure 8.94 in the back of thischapter, generate three multiview sketches. Each sketchshould use a different view of the object as the front view.What features of the object become hidden or visible as youchange the front view?

8.6 FUNDAMENTAL VIEWSOF EDGES AND PLANES

In multiview drawings, there are fundamental views foredges and planes. These fundamental views show theedges or planes in true size, not foreshortened, so that truemeasurements of distances, angles, and areas can be made.

NO!

Figure 8.42 Minimum Number of ViewsSelect the minimum number of views needed to completely describe an object. Eliminate views that are mirror images of other views.

Natural Position

Unnatural PositionNo!

Figure 8.41 Natural PositionAlways attempt to draw objects in their natural position.


8.6.1 Edges (Lines)

An edge is the intersection of two planes and is repre-sented as a line on multiview drawings. A normal line,or true-length line, is an edge that is parallel to a planeof projection and thus perpendicular to the line of sight.In Figure 8.44, edge 1–2 in the top and right side views isa normal edge.

Principles of Orthographic Projection Rule 3:True Length and SizeFeatures are true length or true size when the lines of sightare perpendicular to the feature.

An edge appears as a point in a plane of projection towhich it is perpendicular. Edge 1–2 is a point in thefront view of Figure 8.44. The edge appears as a pointbecause it is parallel to the line of sight used to createthe front view.

An inclined line is parallel to a plane of projectionbut inclined to the adjacent planes, and it appears fore-shortened in the adjacent planes. In Figure 8.44, line 3–4

is inclined and foreshortened in the top and right sideview, but is true length in the front view because it isparallel to the frontal plane of projection.

An oblique line is not parallel to any principal planeof projection; therefore, it never appears as a point or intrue length in any of the six principal views. Instead, anoblique edge will be foreshortened in every view and willalways appear as an inclined line. Line 1–2 in Figure8.45 is an oblique edge.

Principles of Orthographic Projection Rule 4:ForeshorteningFeatures are foreshortened when the lines of sight are notperpendicular to the feature.

8.6.2 Principal Planes

A principal plane is parallel to one of the principalplanes of projection and is therefore perpendicular tothe line of sight. A principal plane or surface will be

No!

Figure 8.43 Most Descriptive ViewsSelect those views which are the most descriptive and have the fewest hidden lines. In this example, the right side view has fewerhidden lines than the left side view.

true size and shape in the view where it is parallel to theprojection plane and will appear as a horizontal or verti-cal line in the adjacent views. In Figure 8.46, surface Ais parallel to the frontal projection plane and is there-fore a principal plane. Because surface A appears truesize and shape in the front view, it is sometimes re-ferred to as a normal plane. In this figure, surface Aappears as a horizontal edge in the top view and as avertical edge in the right side view. This edge represen-


tation is an important characteristic in multiview draw-ings. Principal planes are categorized by the view inwhich the plane appears true size and shape: frontal,horizontal, or profile.

A frontal plane is parallel to the front plane of pro-jection and is true size and shape in the front view. Afrontal plane appears as a horizontal edge in the top viewand a vertical edge in the profile views. In Figure 8.46,surface A is a frontal plane.

1

2

3

4

TOP VIEW

FRONTAL PLANE

PROFILE PLANE

HORIZONTAL PLANE

RIGHT SIDE VIEW

FRONT VIEW

Top View

Line of sight

perpendicular to

line 1–2

Front View

Line of sight

parallel to line

1–2

1

2

3 4

TOP

FRONT RIGHT SIDE

1 2

3

4

4

1,2

3

Figure 8.44 Fundamental Views of EdgesDetermine the fundamental views of edges on a multiview drawing by the position of the object relative to the current line of sightand the relationship of the object to the planes of the glass box.


A horizontal plane is parallel to the horizontal planesof projection and is true size and shape in the top (andbottom) view. A horizontal plane appears as a horizontaledge in the front and side views. In Figure 8.46, surfaceB is a horizontal plane.

A profile plane is parallel to the profile (right or leftside) planes of projection and is true size and shape in theprofile views. A profile plane appears as a vertical edgein the front and top views. In Figure 8.46, surface C is aprofile plane.

8.6.3 Inclined Planes

An inclined plane is perpendicular to one plane of pro-jection and inclined to adjacent planes and cannot beviewed in true size and shape in any of the principalviews. An inclined plane appears as an edge in the viewwhere it is perpendicular to the projection plane and as aforeshortened surface in the adjacent views. In Figure8.46, plane D is an inclined surface. To view an inclinedplane in its true size and shape, create an auxiliary view,as described in Chapter 11.

1

2

FRONTAL PLANEPROFILE PLANE

HORIZONTAL PLANE

1

2

1

2 2

1

Figure 8.45 Oblique LineOblique line 1–2 is not parallel to any of the principal planes of projection of the glass box.


FRONTAL PLANE

RIGHT SIDE

VIEW

PROFILE PLANE


FRONT VIEW

AE

B

D

C

E

D

C

AE

B D

E

RIGHT SIDEFRONT

EdgeViewof A

Edge View of B

Edge View of D

TOP

Edge View of B

Edge View of A

Edge View of C

B

D

E

E

D

CE

A

Figure 8.46 Fundamental Views of SurfacesSurface A is parallel to the frontal plane of projection. Surface B is parallel to the horizontal plane of projection. Surface C is parallelto the profile plane of projection. Surface D is an inclined plane and is on edge in one of the principal views (the front view). SurfaceE is an oblique plane and is neither parallel nor on edge in any of the principal planes of projection.


8.6.4 Oblique Planes

An oblique plane is not parallel to all the principalplanes of projection. In Figure 8.46, plane E is an obliquesurface. An oblique surface does not appear in its truesize and shape, or as an edge, in any of the principalviews; instead, an oblique plane always appears as a fore-shortened plane in the principal views. A secondary aux-iliary view must be constructed, or the object must be ro-tated, in order to create a normal view of an obliqueplane. (See Chapter 12.)

Practice Exercise 8.3Using stiff cardboard, cut out the following shapes:

• Rectangle.• Circle.• Trapezoid.• Irregular shape with at least six sides, at least two of which

are parallel to each other.

Sketch the following multiviews of each shape:

• The line of sight perpendicular to the face.• Rotated 45 degrees about the vertical axis.• Rotated 90 degrees about the vertical axis.• Rotated 45 degrees about the horizontal axis.• Rotated 90 degrees about the horizontal axis.• Rotated 45 degrees about both the vertical and horizontal

axes.

Which views represent true-size projections of the surface?In what views is the surface inclined, oblique, or on edge?What is the shape of a circle when it is foreshortened? Forthe inclined projections, how many primary dimensions ofthe surface appear smaller than they are in true-size projec-tion? What is the relationship between the foreshortened di-mension and the axis of rotation? Identify the parallel edgesof the surface in the true-size projection. Do these edgesstay parallel in the other views? Are these edges alwaysseen in true length?

8.7 MULTIVIEW REPRESENTATIONS

Three-dimensional solid objects are represented on 2-Dmedia as points, lines, and planes. The solid geometricprimitives are transformed into 2-D geometric primitives. Being able to identify 2-D primitives and the3-D primitive solids they represent is important in visual-izing and creating multiview drawings. Figure 8.47shows multiview drawings of common geometric solids.

8.7.1 Points

A point represents a specific position in space and has nowidth, height, or depth. A point can represent

The end view of a line.The intersection of two lines.A specific position in space.

Even though a point does not have width, height, ordepth, its position must still be marked. On technicaldrawings, a point marker is a small symmetrical cross.(See Chapter 6.)

8.7.2 Planes

A plane can be viewed from an infinite number of van-tage points. A plane surface will always project as eithera line or an area. Areas are represented in true size or areforeshortened and will always be similar in configuration(same number of vertices and edges) from one view toanother, unless viewed as an edge. For example, surfaceB in Figure 8.48 is always an irregular four-sided poly-gon with two parallel sides (a trapezoid), in all the princi-pal views. Since surface B is seen as a foreshortened areain the three views, it is an oblique plane.

Principles of Orthographic Projection Rule 5:Configuration of PlanesAreas that are the same feature will always be similar inconfiguration from one view to the next, unless viewed onedge.

In contrast, area C in Figure 8.48 is similar in shape intwo of the orthographic views and is on edge in the third.Surface C is a regular rectangle, with parallel sides la-beled 3, 4, 5, and 6. Sides 3–6 and 4–5 are parallel inboth the top view and the right side view. Also, lines 3–4and 5–6 are parallel in both views. Parallel features willalways be parallel, regardless of the viewpoint.

Principles of Orthographic Projection Rule 6:Parallel FeaturesParallel features will always appear parallel in all views.

A plane appears as an edge view or line when it is par-allel to the line of sight in the current view. In the frontview of Figure 8.48, surfaces A and D are shown as edges.

Principles of Orthographic Projection Rule 7:Edge ViewsSurfaces that are parallel to the lines of sight will appear onedge and are represented as a line.


Rectangular prism Cone Sphere

Pyramid Cylinder

Truncated cone Partial sphere

Prism and cube

Prism and partial cylinder

Prism and cylinderPrism and negative

cylinder (hole)

Figure 8.47 Multiview Drawings of Solid Primitive ShapesUnderstanding and recognizing these shapes will help you understand their application in technical drawings. Notice that the cone,sphere, and cylinder are adequately represented with fewer than three views.


A foreshortened plane is neither parallel nor perpen-dicular to the line of sight. There are two types of fore-shortened planes, oblique and inclined, as described inSections 8.6.3 and 8.6.4. Surface B is foreshortened in allviews of Figure 8.48.

Practice Exercise 8.4Hold an object that has at least one flat surface (plane) atarm’s length. Close one eye, and rotate the object so thatyour line of sight is perpendicular to the flat surface. Whatyou see is a true-size view of the plane. Slowly rotate the ob-ject while focusing on the flat plane. Notice that the flat planebegins to foreshorten. As you continue to rotate the object

slowly, the plane will become more foreshortened until it dis-appears from your line of sight and appears as a line oredge. This exercise demonstrates how a flat plane can berepresented on paper in true size, foreshortened, or as a line.

8.7.3 Change of Planes (Corners)

A change of planes, or corner, occurs when two nonpar-allel surfaces meet, forming a corner, line, or edge. (Fig-ure 8.48 Line 3–4) Whenever there is a change in plane,a line must be drawn to represent that change. The linesare drawn as solid or continuous if visible in the currentview or dashed if they are hidden.

RIGHT SIDEVIEWFront View

Line of sight

PARALLEL to

surface D

1

2

3

4

TOP VIEW

FRONT

VIEW

Top View

Line of sight

INCLINED to

surface C

Front View

Line of sight

PARALLEL to

surface CH

B

A

F

DE

GC

Top ViewLine of sight

PERPENDICULAR to

surface D

6

5

1

2

3 4

5,4

1,2 6,3 6,1 2

3

4

6 5

5

A

D

B

C

H

F

G

B

C

H

D

E

F

G

A

BG

C

EF

H

A

D

E

TOP

FRONT RIGHT SIDE

Figure 8.48 Rule of Configuration of PlanesSurface B is an example of the Rule of Configuration of Planes. The edges of surface C, 3–4 and 5–6, are examples of the Rule ofParallel Features.

8.7.4 Angles

An angle is represented in true size when it is in a nor-mal plane. If an angle is not in a normal plane, thenthe angle will appear either larger or smaller than true


size. For example, in Figure 8.49A, the 135-degreeangle is measured as 135 degrees in the front view,which is parallel to the plane containing the angle. InFigure 8.49B, the angle is measured as less than truesize in the front view because the plane containing theangle is not parallel to the frontal plane and is fore-shortened. Right angles can be measured as 90° in aforeshortened plane if one line is true length. (Figure8.49C)

8.7.5 Curved Surfaces

Curved surfaces are used to round the ends of parts andto show drilled holes and cylindrical features. Cones,cylinders, and spheres are examples of geometric primi-tives that are represented as curved surfaces on techni-cal drawings.

Only the far outside boundary, or limiting ele-ment, of a curved surface is represented in multiviewdrawings. For example, the curved surfaces of the coneand cylinder in Figure 8.50 are represented as lines in thefront and side views. Note that the bases of the cone andcylinder are represented as circles when they are posi-tioned perpendicular to the line of sight.

FORESHORTENEDSURFACE

TRUESIZE SURFACE

135°

(A) (B) (C)

NOTTRUE

ANGLE

90°

Figure 8.49 AnglesAngles other than 90 degrees can only be measured in viewswhere the surface that contains the angle is perpendicular to theline of sight. A 90-degree angle can be measured in aforeshortened surface if one edge is true length.

Cone Cylinder

Area

Limitingelements

Axis(Center line)

Area

Area

Limitingelements

Axis(Center line)

Area

Figure 8.50 Limiting ElementsIn technical drawings, a cone is represented as a circle in one view and a triangle in the other. The sides of the triangle representlimiting elements of the cone. A cylinder is represented as a circle in one view and a rectangle in the other.


Practice Exercise 8.5Hold a 12-ounce can of soda at arm’s length so that yourline of sight is perpendicular to the axis of the can. Closeone eye; the outline of the view should be a rectangle. Thetwo short sides are edge views of the circles representingthe top and bottom of the can. The two long sides representthe limiting elements of the curved surface. Hold the can atarm’s length such that your line of sight is perpendicular tothe top or bottom. Close one eye; the outline should looklike a circle.

Partial cylinders result in other types of multiviewrepresentations. For example, the rounded end of the ob-ject in Figure 8.51 is represented as an arc in the frontview. In the adjacent views, it is a rectangle because thecurve is tangent to the sides of the object. If the curvewere not tangent to the sides, then a line representing achange of planes would be needed in the profile and topviews. (Figure 8.52)

An ellipse is used to represent a hole or circular fea-ture that is viewed at an angle other than perpendicularor parallel. Such features include handles, wheels,clock faces, and ends of cans and bottles. Figure 8.53shows the end of a cylinder, viewed first with a perpen-dicular line of sight and then with a line of sight at 45degrees. For the perpendicular view, the center linesare true length, and the figure is represented as a circle.

(Figure 8.54) However, when the view is tilted, one ofthe center lines is foreshortened and becomes the minoraxis of an ellipse. The center line that remains truelength becomes the major axis of the ellipse. As theviewing angle relative to the circle increases, the lengthof the minor axis is further foreshortened. (Figure 8.54)Ellipses are also produced by planes intersecting rightcircular cones and circular cylinders, as described inSection 6.6.

FRONT

Line indicates notangency

Figure 8.52 Nontangent Partial CylinderWhen the transition of a rounded end to another feature is nottangent, a line is used at the point of intersection.

True lengthcenter lines Ellipse

Minor axis(foreshortened)

Major axis(true length)

Cylinder viewed at90° to its top

surface

Cylinder viewed at45° to its top

surface

Figure 8.53 Elliptical Representation of a CircleAn elliptical view of a circle is created when the circle isviewed at an oblique angle.

FRONT

No lineindicatestangency

Figure 8.51 Tangent Partial CylinderA rounded-end, or partial, cylinder is represented as an arc whenthe line of sight is parallel to the axis of the partial cylinder. Noline is drawn at the place where the partial cylinder becomestangent to another feature, such as the vertical face of the side.

8.7.6 Holes

Figure 8.55 shows how to represent most types of ma-chined holes. A through hole, that is, a hole that goes allthe way through an object, is represented in one view astwo parallel hidden lines for the limiting elements and isshown as a circle in the adjacent view. (Figure 8.55A) Ablind hole, that is, one that is not drilled all the waythrough the material, is represented as shown in Figure8.55B. The bottom of a drilled hole is pointed because alldrills used to make such holes are pointed. The depth ofthe blind hole is measured to the flat, as shown, then 30-degree lines are added to represent the drill tip.

A drilled and counterbored hole is shown in Figure8.55C. Counterbored holes are used to allow theheads of bolts to be flush with or below the surface ofthe part. A drilled and countersunk hole is shown inFigure 8.55D. Countersunk holes are commonly usedfor flathead fasteners. Normally, the countersink is rep-resented by drawing 45-degree lines. A spotfaced holeis shown in Figure 8.55E. A spotfaced hole provides aplace for the heads of fasteners to rest, to create asmooth surface on cast parts. For countersunk, counter-bored, and spotfaced holes, a line must be drawn torepresent the change of planes that occurs between the


large diameter and the small diameter of the hole. Fig-ure 8.55F shows a threaded hole, with two hidden linesin the front view and a solid and a hidden line in thetop view.

8.7.7 Fillets, Rounds, Finished Surfaces, and Chamfers

A fillet is a rounded interior corner, normally found oncast, forged, or plastic parts. A round is a rounded exte-rior corner, normally found on cast, forged, or plasticparts. A fillet or round can indicate that both intersectingsurfaces are not machine finished. (Figure 8.56) A filletor round is shown as a small arc.

With CAD, corners are initially drawn square, thenfillets and rounds are added using a FILLET command.

CAD Reference 8.10Fillets and rounds eliminate sharp corners on objects;

therefore, there is no true change of planes at these placeson the object. However, on technical drawings, only cor-ners, edge views of planes, and limiting elements are rep-resented. Therefore, at times it is necessary to add linesto represent rounded corners for a clearer representationof an object. (Figure 8.57) In adjacent views, lines areadded to the filleted and rounded corners by projecting

(D) What you see: ELLIPSE

Line of sight 30°30°

Minor DiameterMajor Diameter

Fore-shortened

(C) What you see: ELLIPSE

Line of sight 45°

45°

Minor DiameterMajor Diameter

Fore-shortened

(B) What you see: ELLIPSE

Line of sight 80°

80°

Minor Diameter

Major Diameter

Foreshortened

(A) What you see: TRUE SIZE

Edge of circle

Line of sight 90°

Figure 8.54 Viewing Angles for EllipsesThe size or exposure of an ellipse is determined by the angle of the line of sight relative to the circle.


22.1722.23

(G) No! (H) No!

(A) Through hole (B) Blind hole (C) Drilled and counterbored hole

(F) Threaded hole(E) Drilled and spotfaced hole(D) Drilled and countersunk hole

14

(Drill diameter)(Counterbore diameter)(Counterbore depth)

ø 19 (Diameter) 29 (Depth)

ø

Dia.S face dia.

Depth ofspotfaceusually notgiven

ø 16 (Drill diameter)

Drill diameter

Csk dia.

Csk angle

Dia

30°Dep

thDrilldiameter

C bore depth

C bore dia

ø .25 - 20 UNC 2B

Thread note

ø 14Vø 29 × 82°

(Drill diameter)(Countersinkdiameter anangle drawnat 90°)

ø 32 (Spotface diameter)

ø 29ø 29

(Diameter)

MissingLines

Figure 8.55 Representation of Various Types of Machined Holes


Removed roughsurface

Finished

Finished

Sharpcorner

Rough

Rough Round

Rough

Removed roughsurface

Finished

Sharpcorner

Fillet

Round

Rough

Fillet

Rough

Figure 8.56 Representation of Fillets and RoundsFillets and rounds indicate that surfaces of metal objects have not been machine finished; therefore, there are rounded corners.

Projected toadjacent view tolocate line

Figure 8.57 Representing Fillet and Rounded CornersLines tangent to a fillet or round are constructed and then extended, to create a sharp corner. The location of the sharp corner isprojected to the adjacent view to determine where to place representative lines indicating a change of planes.


from the place where the two surfaces would intersect ifthe fillets or rounds were not used. (Figure 8.58) This is aconventional practice used to give more realistic repre-sentation of the object in a multiview drawing.

When a surface is to be machined to a finish, a finishmark in the form of a small v is drawn on the edge viewof the surface to be machined, that is, the finished sur-face. Figure 8.59 shows different methods of represent-ing finish marks and the dimensions used to draw them.

A chamfer is a beveled corner used on the openingsof holes and the ends of cylindrical parts, to eliminatesharp corners. (Figure 8.60) Chamfers are represented aslines or circles to show the change of plane. Chamfers

can be internal or external and are specified by a linearand an angular dimension. With CAD, chamfers areadded automatically to square corners using a CHAM-FER command. CAD Reference 8.11

8.7.8 Runouts

A runout is a special method of representing filleted sur-faces that are tangent to cylinders. (Figure 8.61) A runoutis drawn starting at the point of tangency, using a radiusequal to that of the filleted surface with a curvature of ap-proximately one-eighth the circumference of a circle. Ex-amples of runout uses in technical drawings are shown in

No!

Yes!

Figure 8.58 Examples of Representations of Fillet and Rounded CornersLines are added to parts with fillets and rounds, for clarity. Lines are used in the top views of these parts to represent changes ofplanes that have fillets or rounds at the corners.

Edge view offinished surface

Finish marks

60°3 60°

116

3168

38

Figure 8.59 Finish Mark SymbolsFinish marks are placed on engineering drawings to indicate machine-finished surfaces.

No!

Yes!


Figure 8.62. If a very small round intersects a cylindricalsurface, the runouts curve away from each other. (Figure8.62A) If a large round intersects a cylindrical surface,the runouts curve toward each other. (Figure 8.62C)

CAD Reference 8.12

8.7.9 Elliptical Surfaces

If a right circular cylinder is cut at an acute angle to theaxis, an ellipse is created in one of the multiviews. (Fig-ure 8.63) The major and minor diameters can be pro-jected into the view that shows the top of the cylinder asan ellipse. The ellipse can then be constructed using themethods described in Section 6.6.3. (Figure 8.64)

Internal Chamfer External Chamfer

Figure 8.60 Examples of Internal and External ChamfersChamfers are used to break sharp corners on ends of cylinders and holes.

Point oftangency

A Detail A

Fillets

No fillets

Runout

Fillets

No fillets

Line

No line No line

Fillets

No fillets

Fillets

No fillets

Runout

Figure 8.61 RunoutsRunouts are used to represent corners with fillets that intersect cylinders. Notice the difference in the point of tangency with andwithout the fillets.


(E) (F) (G)

Flat Rounded Flat

(H) (I) (J) (K) (L)

(A) (B) (C) (D)

Flat Flat Rounded Rounded

Figure 8.62 Examples of Runouts in Multiview Drawings

8.7.10 Irregular or Space Curves

Irregular or space curves are drawn by plotting pointsalong the curve in one view and then transferring orprojecting those points to the adjacent views. (Figure8.65) The intersections of projected points locate thepath of the space curve, which is drawn using an irregu-lar curve. With CAD, a SPLINE command is used todraw the curve.

8.7.11 Intersecting Cylinders

When two dissimilar shapes meet, a line of intersec-tion usually results. The conventional practices forrepresenting intersecting surfaces on multiview draw-ings are demonstrated in Figure 8.66, which showstwo cylinders intersecting. When one of the intersect-ing cylinders is small, true projection is disregarded.(Figure 8.66A) When one cylinder is slightly smallerthan the other, some construction is required. (Figure8.66B) When both cylinders are of the same diameter,the intersecting surface is drawn as straight lines. (Fig-ure 8.66C)


MAJORDIAMETER

MINORDIAMETER

Figure 8.63 Right Circular Cylinder Cut to Create anEllipseAn ellipse is created when a cylinder is cut at an acute angle tothe axis.

1

1

2

21 2

3

3 3

4

4 4

Figure 8.64 Creating an Ellipse by Plotting PointsOne method of drawing an ellipse is to plot points on the curveand transfer those points to the adjacent views.

1

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67

89

10

12

34

56

78

910

10

9

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432

1

Figure 8.65 Plotting Points to Create a Space Curve


8.7.12 Cylinders Intersecting Prisms and Holes

Figure 8.67 shows cylinders intersecting with prisms.Large prisms are represented using true projection (Fig-ure 8.67B and C); small prisms are not (Figure 8.67A).Figure 8.68 shows cylinders intersected with piercingholes. Large holes and slots are represented using trueprojection (Figure 8.68B and D); small holes and slotsare not (Figure 8.68A and C).

8.8 MULTIVIEW DRAWING VISUALIZATION

With sufficient practice, it is possible to learn to read 2-D engineering drawings, such as the multiview draw-ings in Figure 8.69, and to develop mental 3-D imagesof the objects. Reading a drawing means being able tolook at a two- or three-view multiview drawing andform a clear mental image of the three-dimensional ob-ject. A corollary skill is the ability to create a multiview

Tangent noline

(A) (B) (C)

Figure 8.67 Representing the Intersection between a Cylinder and a PrismRepresentation of the intersection between a cylinder and a prism depends on the size of the prism relative to the cylinder.

No curve

R

r

r = R

(A) (B) (C)

Figure 8.66 Representing the Intersection of Two CylindersRepresentation of the intersection of two cylinders varies according to the relative sizes of the cylinders.

drawing from a pictorial view of an object. Going frompictorial to multiview and multiview to pictorial is animportant process performed every day by technologists.The following sections describe various techniques forimproving your ability to visualize multiview drawings.Additional information on visualizing 3-D objects isfound in Chapter 5.

8.8.1 Projection Studies

One technique that will improve multiview drawing visu-alization skills is the study of completed multiviews ofvarious objects, such as those in Figure 8.69. Study eachobject for orientation, view selection, projection of visi-ble and hidden features, tangent features, holes androunded surfaces, inclined and oblique surfaces, anddashed line usage.

8.8.2 Physical Model Construction

The creation of physical models can be useful in learningto visualize objects in multiview drawings. Typically,these models are created from modeling clay, wax, or


Styrofoam. The two basic techniques for creating thesemodels are cutting the 3-D form out of a rectangularshape (Figure 8.70) and using analysis of solids (Figure8.71) to divide the object into its basic geometric primi-tives and then combining these shapes. (See Section 8.8.8for more information on analysis of solids.)

Practice Exercise 8.6Figure 8.70 shows the steps for creating a physical modelfrom a rectangular block of modeling clay, based on a multi-view drawing.

Step 1. Create a rectangular piece of clay that is propor-tional to the width, height, and depth dimensions shownon the multiview drawing.

Step 2. Score the surface of the clay with the point of theknife to indicate the positions of the features.

Step 3. Remove the amount of clay necessary to leave therequired L-shape shown in the side view.

Step 4. Cut along the angled line to remove the last pieceof clay.

Step 5. Sketch a multiview drawing of the piece of clay.Repeat these steps to create other 3-D geometricforms.

(B) Large Hole(A) Small Hole

(D) Large Slot(C) Small Slot

Figure 8.68 Representing the Intersection between a Cylinder and a HoleRepresentation of the intersection between a cylinder and a hole or slot depends on the size of the hole or slot relative to the cylinder.


(A) (C) (D)

(E)

(I)

(M)

(Q)

(U)

(F)

(J)

(N)

(R)

(V)

(G)

(K)

(O)

(S)

(W)

(H)

(L)

(P)

(T)

(X)

(B)

Figure 8.69 Examples of the Standard Representations of Various Geometric Forms


8.8.3 Adjacent Areas

Given the top view of an object, as shown in Figure 8.72,sketch isometric views of several possible 3-D forms.Figure 8.73 shows just four of the solutions possible anddemonstrates the importance of understanding adjacentareas when reading multiview drawings. Adjacent areasare surfaces that reside next to each other. The boundarybetween the surfaces is represented as a line indicating achange in planes. No two adjacent areas can lie in thesame plane. Adjacent areas represent

1. Surfaces at different levels.

2. Inclined or oblique surfaces.

3. Cylindrical surfaces.

4. A combination of the above.

Orthographic (A) (B)

(C) (D) (E)

Figure 8.70 Creating a Real ModelUsing Styrofoam or modeling clay and a knife, model simple 3-D objects to aid the visualization process.

Figure 8.71 Analysis of SolidsA complex object can be visualized by decomposing it intosimpler geometric forms.


Going back to Figure 8.72, the lines separating sur-faces A, B, and C represent three different surfaces at dif-ferent heights. Surface A may be higher or lower thansurfaces B and C; surface A may also be inclined orcylindrical. This ambiguity emphasizes the importance ofusing more than one orthographic view to represent anobject clearly.

8.8.4 Similar Shapes

One visualization technique involves identifying thoseviews in which a surface has a similar configuration andnumber of sides. (See Section 8.7.2, Rule 5, configura-

tion of planes, and Rule 6, parallel features.) Similarshape or configuration is useful in visualizing or creatingmultiview drawings of objects with inclined or obliquesurfaces. For example, if an inclined surface has fouredges with opposite edges parallel, then that surface willappear with four sides with opposite edges parallel in anyorthographic view, unless viewing the surface on edge.By remembering this rule you can visually check the ac-curacy of an orthographic drawing by comparing theconfiguration and number of sides of surfaces from viewto view. Figure 8.74 shows objects with shaded surfacesthat can be described by their shapes. In Figure 8.74A,the shaded surface is L-shaped and appears similar in thetop and front views, but is an edge in the right side view.In Figure 8.74B, the shaded surface is U-shaped and is

Top

Front Right side

Isometric

? ?

?A

B

C

Figure 8.72 Adjacent AreasGiven the top view, make isometric sketches of possible 3-Dobjects.

Figure 8.73 Possible Solutions to Figure 8.72

(A) (B) (C) (D)

Figure 8.74 Similar-Shaped SurfacesSimilar-shaped surfaces will retain their basic configuration in all views, unless viewed on edge. Notice that the number of edges ofa face remains constant in all the views and that edges parallel in one view will remain parallel in other views.


configured similarly in the front and top views. In Figure8.74C, the shaded surface is T-shaped in the top andfront views. In Figure 8.74D, the shaded surface haseight sides in both the front and top views.

8.8.5 Surface Labeling

When multiview drawings are created from a given pic-torial view, surfaces are labeled to check the accuracy ofthe solution. The surfaces are labeled in the pictorialview and then in each multiview, using the pictorial viewas a guide. Figure 8.75 is the pictorial view of an object,with the visible surfaces labeled with a number; for ex-ample, the inclined surface is number 5, the oblique sur-face is number 8, and the hole is number 4. The multi-view drawing is then created, the visible surfaces in eachview are labeled, and the results are checked against thepictorial.

8.8.6 Missing Lines

Another way of becoming more proficient at reading anddrawing multiviews is by solving missing-line problems.Figure 8.76 is a multiview drawing with at least one linemissing. Study each view, then add any missing lines tothe incomplete views. Lines may be missing in more thanone of the views. It may be helpful to create a rough iso-metric sketch of the object when trying to determine thelocation of missing lines.

3 5

98

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1

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32

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92

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1

Figure 8.75 Surface LabelingTo check the accuracy of multiview drawings, surfaces can belabeled and compared with those in the pictorial view.

A

Completed multiview

A

Missing feature

Figure 8.76 Missing-Line ProblemsOne way to improve your proficiency is to solve missing-line problems. A combination of holistic visualization skills andsystematic analysis is used to identify missing features.


Locating Missing Lines in anIncomplete Multiview Drawing

Step 1. Study the three given views in Figure 8.76.Step 2. Use analysis by solids or analysis by surfaces, as

described earlier in this text, to create a mental image ofthe 3-D form.

Step 3. If necessary, create a rough isometric sketch of theobject to determine the missing lines.

Step 4. From every corner of the object, sketch construc-tion lines between the views. Because each projectedcorner should align with a feature in the adjacent view,this technique may reveal missing details. For the fig-ure, corner A in the right side view does not align withany feature in the front view, thus revealing the locationof the missing line.

8.8.7 Vertex Labeling

It is often helpful to label the vertices of the isometricview as a check for the multiview drawing. In the isomet-ric view in Figure 8.77, the vertices, including hiddenones, are labeled with numbers, then the correspondingvertices in the multiviews are numbered. In the multi-views, hidden vertices are lettered to the right of thenumbered visible vertices. For example, the vertices ofsurface A are numbered 1, 2, 3, and 4. In the front view,surface A appears on edge, and vertices 1 and 4 are infront of vertices 3 and 2. Therefore, in the front view, thevertices of surface A are labeled 4, 3 and 1, 2.

8.8.8 Analysis by Solids

A common technique for analyzing multiview drawingsis analysis by solids, in which objects are decomposedinto solid geometric primitives such as cylinders, nega-tive cylinders (holes), square and rectangular prisms,cones, spheres, etc. These primitives are shown in Figure8.47 earlier in this chapter. Their importance in the un-derstanding and visualization of multiview drawings can-not be overemphasized.

Figure 8.78 is a multiview drawing of a 3-D object.Important features are labeled in each view. Planes arelabeled with a P subscript, holes (negative cylinders) withan H subscript, and cylinders (positive) with a C subscript.

Analysis by Solids

Step 1. Examine all three views as a whole and then eachview in detail. In the top view is a rectangular shape la-beled AP and three circles labeled GH, HC, and IH. On theleft end of the rectangular area are dashed lines repre-senting hidden features. These hidden features are la-beled DP, EC, and FH.

Step 2. In the front view is an L-shaped feature labeled BP.At opposite ends of the L-shaped area are dashed linesrepresenting hidden features and labeled GH and FH. Ontop of the L-shaped area is a rectangular feature withdashed lines representing more hidden features. Therectangular feature is labeled Hc and the hidden featureis labeled IH.

Step 3. In the right side view are two rectangular areas,and a U-shaped area with a circular feature. The rectan-gular feature adjacent to and above the U-shaped area islabeled CP and has hidden lines labeled GH. The rectan-gular feature above CP is labeled HC and contains dashedlines labeled IH. The U-shaped area is labeled DP, and thearc is labeled EC. The circular feature in the U-shapedarea is labeled FH.

Figure 8.77 Numbering the Isometric Pictorial and theMultiviews to Help Visualize an Object

8

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12,13 11,5 4,1

9 10

4,5 3,6

A

Top view

A

A A

Front view Right side

7

This general examination of the views reveals someimportant information about the 3-D form of the object.Adjacent views are compared with each other, and paral-lel projectors are drawn between adjacent views to helpfurther analysis of the object.

Step 4. In the top view, rectangular area AP extends the fullwidth of the drawing, can only be aligned with area BP inthe front view, and appears as an edge in the front andright side views. Area BP in the front view is aligned witharea CP in the right side view. BP appears as a verticaledge in the right side view and a horizontal edge in thetop view. The conclusion is that areas AP, BP, and CP aretop, front, and right side views, respectively, of a rectan-gular prism, which is the main body of the part.

Step 5. Circular area GH in the top view is aligned with thehidden lines labeled GH in the front view. Because thesehidden lines go from top to bottom in the front view, it isconcluded that the circle represents a hole. This can beverified by the dashed lines GH in the right side view.

Step 6. In the front view, rectangular area HC projectsabove the main body of the part; therefore, it should bevisible in the top view. This rectangular area is in align-ment with circular area HC in the top view and with rectan-gular area HC in the right side view. The conclusion is that


area HC is a cylinder because it appears as a circle inone view and as a rectangle in the other two views.

Step 7. The circle IH in the top view is aligned with dashedlines IH in the front view and is inside cylinder HC. This in-dicates that circle IH in the top view is a negative cylinder(hole) centered within cylinder HC. The dashed line la-beled Z in the front and right side views shows the depthof the negative cylinder IH.

Step 8. In the top view, the dashed lines at the left end ofrectangular area AP represent one or more feature(s)below the main body of the part. Hidden line DP in the topview is aligned with visible line DP in the front view, anddashed lines FH in the top view are directly above dashedlines FH in the front view. Area EC in the top view isaligned with area EC in the front view. So the features hid-den in the top view must be DP and EC in the front view.

DP and EC in the front view are aligned with DP and EC inthe right side view. The right side view appears to be themost descriptive view of these features. In this view, areaEC is a partial cylinder represented by arc EC. The sideview also reveals that dashed lines FH in the top and frontviews represent the diameter of hole FH. Therefore, areaDP and partial cylinder EC are a U-shaped feature with ahole whose width is revealed in the front and top views.

I H

HC A P

C P

G HB P

D PEC

FH

D P

B P

G H

C P

I H

HC

FH

A PZ

EC

Z

I H

HC

C P

A P

D P

FHEC

B P

G H

Figure 8.78 Visualizing a Multiview Drawing Using Analysis by Solids


Analysis by solids should result in a clear mental imageof the 3-D form represented in a 2-D multiview drawing.Figure 8.79 is a pictorial view of the object in the multi-view drawing, and it should be similar to the mental imagecreated after following the preceding eight steps.

8.8.9 Analysis by Surfaces

Figure 8.79 lends itself to analysis by solids becausethere are no inclined or oblique surfaces. With inclinedand oblique surfaces, such as those shown in Figure 8.80,analysis by surfaces may be more useful.

Analysis by Surfaces

Step 1. Examine all three views in Figure 8.80. There areno circular or elliptical features; therefore, all the areasmust be bounded by planar surfaces. In the top view,areas A and B are separated by lines; therefore, they arenot in the same plane. The same is true for areas C andD in the front view and areas E and F in the right sideview. The reason for this is that no two contiguous (adja-cent) areas can lie in the same plane. If they were in thesame plane, a line would not be drawn to separate them.This is an example of Rule 8.

Step 2. The lines of projection between the top and frontviews indicate that area B corresponds to area D. AreasB and D are also similar in shape in that they both havesix sides, thus reinforcing the possibility that areas B and

D are the same feature. Similarly, areas A and C arealigned and are similar in shape, so they could be thesame feature. However, before accepting these two pos-sibilities, the side view must be considered.

Step 3. Area D aligns with area F, but they are not similarin shape; area F is three-sided and area D is six-sided.Therefore, areas D and F are not the same feature. In theright side view, area D must be represented as an edgeview separating areas E and F; therefore, area D is the in-clined plane in the right side view. Area C aligns with

FRONT

VIEW

RIGHT SIDEVIEW

TOPVIEW

CP

DP BP

AP

HC

I H

GH

F H

EC

Figure 8.79 A Pictorial View of the Multiview Drawing in Figure 8.78, Revealing Its Three-Dimensional Form

A

B

C

D

E

F

Figure 8.80 Visualizing a Multiview Drawing UsingAnalysis by Surfaces

area E, but they are not similar in shape; area C is four-sided, and area E is three-sided. In the right side view,area C must be represented as an edge view and is thevertical line on the left side of the view.

Step 4. Areas E and F are not represented in the top orfront views; therefore, areas E and F are edge views inthe front and top views. (Figure 8.81) Because areas Eand F are visible in the right side view, they are at theright end of the front and top views. Therefore, they mustbe located at the right end of the object.

Step 5. Based on alignment and similarity of shape, sur-faces B and D must be the same surface.

Step 6. Area A in the top view is an edge view representedas a horizontal line in the front and side views. Area C inthe front view is a horizontal edge view in the top viewand a vertical edge view in the right side view. Areas Aand C are therefore not the same.

Figure 8.82 is a pictorial view of the object. Areas Band D are the same inclined plane, area A is a horizontalplane, and areas C, E, and F are vertical planes.

Principles of Orthographic Projection Rule 8:Contiguous AreasNo two contiguous areas can lie in the same plane.

8.9 ANSI STANDARDS FORMULTIVIEW DRAWINGS

Standards form the common language used by engineersand technologists for communicating information. Thestandard view representations developed by ANSI for mul-tiview drawings are described in the following paragraphs.


8.9.1 Partial Views

A partial view shows only what is necessary to com-pletely describe the object. Partial views are used for sym-metrical objects, for some types of auxiliary views, andfor saving time when creating some types of multiviewdrawings. A break line (shown as a jagged line) or centerline for symmetrical objects may be used to limit the par-tial view. (Figure 8.83) If a break line is used, it is placedwhere it will not coincide with a visible or hidden line.

Partial views are used to eliminate excessive hiddenlines that would make reading and visualizing a drawingdifficult. At times it may be necessary to supplement apartial view with another view. For example, in Figure8.84, two partial profile views are used to describe theobject better. What has been left off in the profile viewsare details located behind the views.

Figure 8.81 Conclusions Drawn about Figure 8.80

A

EC

F

B = D

Figure 8.82 A Pictorial View of Figure 8.80, Revealing ItsThree-Dimensional Form

Center line Break line

Figure 8.83 A Partial View Used on a Symmetrical ObjectThe partial view is created along a center line or a break line.

A

B = D

C

D = B

E

F

C

E

A

C

A

D

E

F

F


8.9.2 Revolution Conventions

At times, a normal multiview drawing will result inviews that are difficult to visualize and read. This is espe-cially true of objects with ribs, arms, or holes that are notaligned with horizontal and vertical center lines. Figure8.85 shows an object with ribs and holes that are equallyspaced, with the two bottom holes not aligned with thecenter line of the object. True projection produces anawkward profile view that is difficult to draw because allbut one rib are foreshortened. (Figure 8.85A) ANSI stan-dard revolution conventions allow the profile view to bedrawn as shown in Figure 8.85B. You must visualize theobject as if the ribs are revolved into alignment with thevertical center line in the front view. This will produce aprofile view that is easier to visualize and draw.

Revolution conventions can also be used on partsthat have bolt circles. Figure 8.86 shows the true pro-

jection of a plate with a bolt circle. Notice that the pro-file view becomes difficult to read because of so manyhidden lines. As shown in Figure 8.86, revolution con-ventions dictate that only two of the bolt circle holesmust be represented in the profile view. These two boltcircle holes are aligned with the vertical center line inthe front view and are then represented in that positionin the profile view.

Figure 8.87 shows another example of revolutionconventions. The inclined arms in the figure result in aforeshortened profile view, which is difficult and timeconsuming to draw. Revolution conventions allow thearms to be shown in alignment with the vertical centerline of the front view to create the profile view shown inthe figure.

Objects similar to those described in the precedingparagraphs are frequently represented as section views.When revolution techniques are used with sectionviews, the drawings are called aligned sections. (SeeChapter 14.)

Revolution conventions were developed before CAD.With the advent of 3-D CAD and the ability to extractviews automatically, it is possible to create a true-projec-tion view, such as that shown in Figure 8.87, quickly andeasily. You are cautioned that, even though a view can beautomatically produced by a CAD system, this does notnecessarily mean that the view will be easy to visualizeby the user.

Figure 8.84 Use of Two Partial Profile Views to Describean Object and Eliminate Hidden Lines

(A) True projection (B) Preferred

Figure 8.85 Revolution Convention Used to Simplify the Representation of Ribs and Webs

Practice Exercise 8.7In Figures 8.85 through 8.87, a new revolved view was cre-ated to replace a true projection in the profile view. This wasdone in order to represent the features of the object moreclearly. Sketch new front views as if the new profile viewsrepresented true projections.

8.9.3 Removed Views

At times, it is important to highlight or enlarge part ofa multiview. A new view is drawn that is not in align-ment with one of the principal views, but is removedand placed at a convenient location on the drawingsheet. A removed view is a complete or partial ortho-graphic view that shows some details more clearly. Anew viewing plane is used to define the line of sightused to create the removed view, and both the viewingplane and the removed view are labeled, as shown inFigure 8.88.

8.10 SUMMARY

Multiview drawings are an important part of technicalgraphics. Creating multiview drawings takes a high de-gree of visualization skill and considerable practice. Mul-tiview drawings are created by closely following ortho-graphic projection techniques and ANSI standards. Therules of orthographic projection are listed here for yourreference.


Rule 1: Every point or feature in one view must bealigned on a parallel projector in any adjacentview.

Rule 2: Distances between any two points of a fea-ture in related views must be equal.

Rule 3: Features are true length or true size when thelines of sight are perpendicular to the feature.

Rule 4: Features are foreshortened when the lines ofsight are not perpendicular to the feature.

Rule 5: Areas that are the same feature will alwaysbe similar in configuration from one view to thenext, unless viewed as an edge.

Rule 6: Parallel features will always appear parallelin all views.

Rule 7: Surfaces that are parallel to the lines of sightwill appear as lines or edge views.

Rule 8: No two contiguous areas can lie in the sameplane.

PreferredTrue projection

Figure 8.86 Revolution Convention Used on Objects withBolt Circles to Eliminate Hidden Lines and ImproveVisualization

True projectionPreferred

Figure 8.87 Revolution Convention Used to Simplify theRepresentation of Arms

Scale - 4/1View A

A

Figure 8.88 A Scaled Removed View (View A)


Questions for Review

1. Define orthographic projection.

2. How is orthographic projection different fromperspective projection? Use a sketch to highlightthe differences.

3. Define multiview drawings. Make a simple multi-view sketch of an object.

4. Define frontal, horizontal, and profile planes.

5. List the six principal views.

6. Define fold lines.

7. List the space dimensions found on a front view,top view, and profile view.

8. Define a normal plane.

9. Define an inclined plane.

10. Define an oblique plane.

11. List the eight rules of orthographic projection.

Problems

Integrated Design Communications Problem

Gear reducer assignment 6Each member of the team will take his or her assigned part(s)and the design sketches created earlier and will begin to cre-ate multiview drawings of those parts, using hand tools orCAD. If 3-D models were created earlier and the CAD soft-ware is capable, extract the multiviews from the models, asdescribed in this chapter. When creating the multiviews, re-member to choose the most descriptive views and to leaveenough space between the views to add dimensions later.

8.1 (Figure 8.89) Draw or sketch the front, top, andright side views of the object shown in the pictor-ial. Number each visible surface in each of themultiviews to correspond to the numbers given inthe pictorial view.

8.2 (Figure 8.90) Draw or sketch the front, top, andright side views of the object shown in the pictorial.

Number each visible surface in each of the multi-views to correspond to the numbers given in thepictorial view.

8.3 (Figure 8.91) Given the front view shown in the fig-ure, design at least six different solutions. Sketch yoursolutions in pictorial and in front and side views.

8.4 (Figure 8.92) Given the two views of a multiviewdrawing of an object, sketch or draw the givenviews, freehand or using instruments or CAD, andthen add the missing view. As an additional exer-cise, create a pictorial sketch of the object.

8.5 (Figure 8.93) Given three incomplete views of amultiview drawing of an object, sketch or draw thegiven views, freehand or using instruments orCAD, and then add the missing line or lines. As anadditional exercise, create a pictorial sketch of theobject.

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Figure 8.89 Solid Object for Problems 8.1, 8.11, and 8.12

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Figure 8.90 Solid Object for Problem 8.2

8.6 (Figure 8.94) Sketch, or draw with instruments orCAD, multiviews of the objects shown in thepictorials.

8.7 (Figures 8.95 through 8.184) Sketch, draw withinstruments or CAD, or create 3-D CAD modelsfor the parts shown.

8.8 On square grid paper, sketch a series of multi-views of a cube, at least eight squares on a side.Visualize the following modifications to the cubeand draw the resulting multiviews:

a. Looking at the front view, drill a hole 3squares in diameter and parallel to the line ofsight.

b. Take the result of (a) and drill another hole 2squares in diameter to the right of the firsthole.

c. Take the result of (a) and drill another hole 3squares in diameter above the first hole.

d. Take the result of (a) and drill a hole 5 squaresin diameter in the same location as the firsthole, but only half-way through the cube.

e. Instead of drilling a 3-square diameter holethrough the object, create a cylinder projecting2 squares out of the cube and parallel to theline of sight of the front view. Compare thiswith the views in (a).


f. Same as (e), except raise the cylinder along theline of sight of the top view.

g. Same as (a), except remove a square featurerather than a round hole. Compare this withthe views in (a).

h. Same as (a), except place the center 2 squaresto the right. Enlarge the drill to a diameter of 5squares; 7 squares; 9 squares.

i. Find the midpoints of the top and right sideedges of the front view. Draw a line connect-ing these points and project it along the lineof sight for the front view to create a cuttingplane. Remove this corner of the cube.

j. Same as (i), except rotate the cutting plane tobe 15°, 30°, 60°, and 75° to the horizontal.Compare the dimensions of the inclined sur-face projections at each of these angles (in-cluding the original 45° angle).

k. Same as (i), except move the cutting plane to-ward the lower left corner of the front view, in2-square increments. When is the inclined sur-face the largest?

l. Same as (i), except the cutting plane is definedby the midpoints of the top and right sideedges of the front view and the midpoint of thetop edge of the right side view.

m. Same as (l), except move the cutting plane in2-square increments toward the opposite cor-ner of the cube.

8.9 Same as 8.8 (a through k), except use a cylinder 8squares in diameter, 8 squares deep, and seen inits circular form in the front view.

8.10 Using any of the objects shown in the exercises inthe back of this chapter, decompose the objectsinto primitive geometric shapes. Color code theseshapes to show whether they represent positivematerial added to the object or negative materialremoved from it. This can be done by:

• Drawing isometric pictorial sketches of theobjects.

• Overdrawing on top of photocopies of thedrawings.

• Tracing over the drawings.

EXAMPLE

Figure 8.91 Front View for Problem 8.3


(3)(2)

(4) (5) (6)

(7) (8) (9)

(10) (11)

(1)

(12)

Figure 8.92 Two-View Drawings of Several Objects for Problem 8.4


(13) (14) (15)

(16) (17) (18)

(19) (20) (21)

(22) (23) (24)

Figure 8.92 Continued


(28) (29) (30)

(26) (27)

(31) (32)

(34) (35)

(33)

(25)

(36)



(2) (3)

(4) (5) (6)

(7) (8) (9)

(10) (11)

(1)

(12)

Figure 8.93 Three Incomplete Views of a Multiview Drawing of an Object for Problem 8.5


(13) (14) (15)

(16) (17) (18)

(19) (20) (21)

(22) (23) (24)



(12)

(1) (2) (3)

(4) (5) (6)

(7) (8) (9)

(10) (11)

Figure 8.94 Pictorials of Several Objects for Problems 8.6 and 8.13


(24)(23)

(13) (14) (15)

(16) (17) (18)

(19) (20) (21)

(22)



(33)

(25) (26) (27)

(28) (29) (30)

(31) (32)

(34) (35) (36)



8.11 Using either a photocopy or a tracing of the objectin Figure 8.89, color, number, or letter each face(surface) of the object. Pick a surface that will beseen in its true size and shape in the front viewand sketch its representation in the three primarymultiviews. Use projection lines to align the

surface in all three views. Label it the same asyou did in the pictorial. Then, pick another sur-face that shares an edge with the one you justsketched, and sketch the new surface in the threeviews. Repeat the process until you have sketchedall the faces contiguous with the original one.

2X ø .75

7.004.50

2.00

2.00

2.00

1.00

5.00

1.00

1.50

1.50

4.50

.50

.75

Figure 8.95 Tool Block

ø 2.00

1.00.50

4.00

2.00

3.50

3.006.00

.50

Figure 8.96 Wedge Support

.25

ø .25

60°

ø 1.00

.0918

Figure 8.97 Ratchet

.570

.125

40°.160

R .340

R .560

.125

R .1875

Figure 8.98 Ratchet Stop


How many of these faces are contiguous witheach other? How many are also seen in their truesize and shape in the front view? In other views?

8.12 Using the object in Figure 8.89, identify the nor-mal, inclined, and oblique planar surfaces. Eitherletter, number, or color code the surfaces on atracing paper copy or a photocopy of the pictorial.

a. Create a multiview of the object and identifythe same surfaces in all three views. In whichviews are individual surfaces seen in their truesize and shape? In which views are individualsurfaces foreshortened? (Which dimension isforeshortened?) In which views are individualfeatures seen as edges?

b. For the inclined surfaces, identify which edgesshow up as normal or non-normal (angled)edges on normal surfaces. How does the in-clined surface appear in the view where a non-normal edge is present?

c. For the oblique surfaces, are there any normaledges? Is there any view in which any of thesesurfaces are seen as edges?

d. Visualize a view which would allow an in-clined or oblique surface to be seen in its truesize and shape, and try to sketch that view.What happens to the surfaces which were nor-mal in the principal views?

8.13 Using any of the objects from Figure 8.94, sketchthem on tracing paper or make a photocopy. Sketchcutting planes which would divide all or part ofeach object into symmetrical halves. Sketch multi-views of each half of each object.

4.50

ø .313

.75

.062

.375

R .844

45°

R .906

5°

1.000

.50

R 1.1181.00

R .063

.375 THICK

Figure 8.99 Lever

ø .458

.750

ø .144

.255

.02 X 45°

.780

.630

.06

.06

R .315

.25

R .59

.375

Figure 8.100 Coupling


4.00 ø 2.00

ø 1.50

5X .03 X 45°

ø 2.3754.625

2.125

R .50

.70

Figure 8.101 Retainer

3.506.50

9.50

ø 7.00

ø 4.00

ø 3.50

Figure 8.102 Half Pin

.938

ø .750

ø 1.000

ø .563

ø .250

.438

.688

R 1.190

Figure 8.103 Timing Knob

R .125NECK ø .447-MINIMUM

.406

.188

.625

.031 CHAMFERø .5

31

.063 X 45°

ø .3125-18 TAP

ø .531

.018 Thick

Figure 8.104 Latch Nut

3.00

R .250

1.50

3.4375

3.00

ø .500

.75

108°

1.50

Figure 8.106 Snubber

6.00

R .7502X ø .6250

2.250

2.00

.125

76°

1.500

.500

4.50

1.6425

.4034

5.00

BEND RADIUS .125

8.00

Figure 8.105 Top Bracket


ø .5000ø .4370

ø .3748.5000

1.6250

.3750

1.0000

.125 x 45°

.1457.1875

ø .250

Figure 8.107 Dial Extension

ø 2.250

ø .3140.7344

0.3594

ø .375

.0625 X 45°

ø 1.3123 X 0.0156

RAISED FACE

ø 1.2498

Figure 8.108 Spacer

2X ø 20.60

100.0068.00

70.00

32.0019.00

106.00

20.0030.00

70.00R 6.40

15.80180.00

264.20

R 5.00METRIC

Figure 8.109 Motor Plate

R .313

1.22

4.00

ø .313ø .063

ø .550

.313.313

.4380

ø .375

Sø .550

ø .375-24X .375

ø .063.469

Figure 8.110 Handle

1.00

60°

.6250

R .2500

.3660

.500

R 1.00R .8148

1.1250

ø 1.8125

Sø 2.0000

Sø 2.3783

60°

Figure 8.111 Release


#1#4#5

#8

#7

#2

#6#3

CENTRAL AXIS

CENTRAL AXIS TUBE

Central axis tube height = 11.000"

Central axis tube I.D. = 7.250"

Central axis tube O.D. = 8.000"

Central axis tube flange dia = 10.000"

Central axis tube flange width = .500"

All flange diameters = tube diameter + 1.5"

All flange widths = .500"

All tube I.D.'s = Tube diameter - .500"

Tube #Elevation from base(on the central axis)

4.000"

7.000"

7.000"

4.000"

2.750"

9.125"

4.625"

4.500"

Azimuth angle from tube#1 (around central axis)

0°180°110°70°310°310°205°230°

Offset distance fromcentral axis

0.000"

0.000"

0.000"

2.000"

0.500"

0.750"

0.125"

0.250"

Angle of elevationfrom the base of

the part

0°0°

-45°-10°

30°

0°-30°

Length of tube from end offlange to apparent intersection

with central axis

Outer diameter oftube

3.000"

2.500"

3.500"

1.750"

1.750"

1.750"

1.750"

1.750"

0°

14.000"

11.000"

9.250"

9.500"

5.000"

5.500"

6.000"

7.500"

1

2

3

4

6

7

8

5

Figure 8.112 Evaporator

3X ø 2.0625 OFFSET 60°

AROUND CENTRAL AXIS

R .3125

1.000.7187

.4375.2188.1562

22 TEETH-PITCH ANGLE 90°

INNER AND ROOT DIAMETERS AS SHOWN

.0625 X 45° CHAMFER AT BOTTOM

.1303 X 30° CHAMFER AT TOP

Sø 2.000

ø 1.000

ø .875

ø 1.1356

.2813

Figure 8.113 SwivelR .3750

5°

35°.6188 .4544

.8688.4801

.0168

.8438

.5244.0312

.10921.5787

1.7399

.9732

.0781

.4062

.2171

.0312

SECTION A-A

1.9611

1.6917

.2191

9.5000

2.3594

8.7813

.3438

.4377

ø .5000ø .4000

.75

.8567

.7409

.0592.1250

R 1.7500

8.2482

1.2317 .808

1.9688

1.7134

R .2500

R .2500

A

A

.8794

ø .300

.1362

.1639

Figure 8.114 L-Slide


2.2

13.6

3.34.5R 2.13.4

.8

9.0

18.2

.8

6.7

2.2

3.010.4

9.4 4.7

ø 1.6ø 3.61.0

3.0

2.4

33.230.021.83.8

5°

1.6

4.8

2.2

2X ø .8

.8 X 45°

5.0.6

3.6

3.2

2.4

4.8

ø 1.2

CL

1.00

Figure 8.115 Manifold

.25

R .37

4.63

2.631.88

.63

1.50

2.25

.501.13

2X ø .88

1.25

115°

3.25

.25

1.13

2.881.75

.75

2.00

6.88 7.38

CL

Figure 8.116 Seat

R 26

12

136

15°

120°

ø 525

ø 84

ø 16

ø 68

94

90

60

120

86

58

8X ø 5

8 X 45°

ø 42 B.C.

2428

ø 32

METRIC

Figure 8.117 Propeller

16

3X R 22

2X R 30

8

82

28

42

82

3X ø 20

5470

3X ø 24

84R 16

150

42

59

70

METRIC

Figure 8.118 Cutoff

.50

1.13

.06

R .25

ø .19

.75

.25

1.25

.13

.62

.13

.13

.13

.19.63

.751.25

1.38

1.632.06

2.81

3.00

3.38

.25

45°

.44

.13

Figure 8.119 Folder


.6250

ø.6249

.6250.2500

.8750

.3750

.1758

.1250

1.3750

3.4375

1.5625

1.2500

.7578

.5000

R .1250

.2500.1250

.2500

.4688

.6250

.0625

.3867.2344

.0613

.4453.3835

ø.6249

.7578

.5189

ø.3461ø.4609

.5103

3.2500

.6494

.3477

.5000

.3750

.875

.035

NOTE: ALL CHAMFEREDEDGES .125 X 45° U.O.S.FILLETS & ROUNDS R .0625

ø.4505

Figure 8.121 Sensor

ø 1.20

.05 X 45°

1.20

.20.20

ø 2.00

15°

ø 1.40

.20

.30

ø 2.00

.20

ø .40

ø .60

.30

1.702.30

.80

ø 4.00

ø 3.75

Figure 8.122 Index

84

ø 192

104

36

12

ø 33ø 88176

R 78R 104

R 12ø 552

ø 128ø 290R 2060

104

R 16R 80

R 100

116

R 8

ø 288 84

12

8 BLADES EQ SP

4 BLADES EQ SP

R .56

ø 228METRIC

Figure 8.123 Slinger

1.13

R 3.63

.75

.37

.75

2.75

15.56 ø 4.63

22X ø .19

1.38ø 2.00ø 3.00

1.75

ø 3.50R 2.87

R 2.25ø 2.69

1.75

R 1.12

.38

R .38

R .96

Figure 8.124 Spray Arm

METRIC

10

120°

ø 52

4868

R 36ø 88

16

55°

R 58

12

36

48

20°

35°ø 12

82

R 12

R 14

32

3X R 49

Figure 8.120 Spline Pilot


METRIC

1.310.8ø 14.8

R 9.2

R 1.8

18.4

5.2

11.0

3.6

3.6

R 2.6

ø 8.0

12.8

5.2

14.1

15.717.9

45.3

68.9

11.5

Figure 8.125 Arm Support

TAB ON BOTH SIDES

2.25

R .25

2X ø .38

R .31

.94

1.88

4.44

.25.50

.88

4.31

2.63.501.13

.44.88

.25

12.38

.44

2.36 .94

ø .50.25

2.38

.44

Figure 8.126 Control Back

METRIC

ø 28

90°

4X ø 6

ø 12

ø 52ø 44

R 5

19

3

16 22 R 112

8

66 80 88

R 4

8

34

ø 80

63

Figure 8.127 Inlet

METRIC

5X R 30

8

ø 56

12

ø 12

ø 243

5X 72°

R 58

8

Figure 8.128 Gear Index

1.88

1.63

ø 2.26

4X ø .50

2.38

4.63

7.502.38

R 1.13

1.13

Figure 8.129 Speed Spacer

.63

ø 1.50

4.13

3.38

2.00

ø .63

1.38

1.25

.63

R .25

Figure 8.130 Shaft Support


METRIC

19

68 R 16

18

20°37

21

R 15

17

R 942

R 2ø 16

15° ø 12

R 21

13

13

17

Figure 8.133 CNC Clamp

1.001.25

ø 1.00

1.75.63 1.38

2.50

1.50

R .25

R 2.25

ø .50

ø .87 X 82°

.30

3.75

2X ø .63

ø 1.00

.50

1.13

1.00 2.00

2.25

1.63

1.63

ø 2.00

1.13

ø .75

2.24

Figure 8.134 Pen Block

3.10

.50

.60

1.30

.80.30

1.001.90

6.30

8.90

R .50

ø .602.10

2.50

5.00

ø .80ø 1.80.50

2.50

R 3.30

.40

R 1.501.60

.90

.90

.401.10

2X ø .40 .75

Figure 8.135 Index Support

FILLETS & ROUNDS R .13

2.00

.88

2X ø .63

1.00

3.291.00

2.00

2X ø .75ø 1.00

.50

1.00

2.00

ø .94

ø 1.75

2.00

1.131.75

1.75 3.25 .63

CL

.88

Figure 8.136 Cover Guide

.50

.88

.50

1.75

1.00

ø .63

R .25

1.76

1.00

Figure 8.131 Stop Base

.50

ø .62

.75 1.00 1.75

.38.88

1.25

.63

1.50 1.37

1.62

3.501.38

.50

Figure 8.132 Tool Holder


2.250

30°

1.375

1.125

2.250 .625

4X R .25

3.000

.500

2X ø .50

.750

.938

.563

.875.500

.750

.625

1.375

.313

.500

Figure 8.137 Dial Bracket

2X ø .188

.437

.188

R .250

R .375

R .375

1.50

ø .500

Figure 8.138 Bearing Block

.437

1.250

.375

R .937

.563

3X ø .250

3X R .250.563

.625

.250

.2505

1.000

1.063

.313

1.813

R 1.438

ø 1.000

ø .625

.563

Figure 8.139 Pulley Support

.56

1.07

1.05

4.26

1.26

.66

.49.90

ø .30

.50

3.18

1.44

.41

ø .40.10

1.26.30

ø .90

.50.53

.41.12

2.21

.32

60°

.43.40

Figure 8.140 Centering Clip

METRIC

522

336

438393

R 84

R 45

SR 48

111195

189

R 30

174

R 237

R 153

120

R 21

6 BLADES EQ SP

Figure 8.141 Impeller

ø 1.00

.50

.50

R .50

2.50

1.001.00

4.00

.275

ø .25

2.00

.275

.25

1.125

R .375

ø .75

1.18

2.25

R .18

CL 1.00

Figure 8.142 Adjustable Guide


.30

R 1.06

3.00

2.40.95

.73.30

.63

.48ø .95 CENTERED

.63

1.75

4X ø .30

4X R .14.325

.40

3.20

4.00

.50

1.402.40

R .50

1.45

1.20

R .50TYP

.15

.60

2.30

.77

R .75

.48

.70

Figure 8.146 Dryer Clip

.70

2.80

.625

.54

.60

1.40

R .40

.71.50

1.20R .75

.53

2.00

R 1.52.00

4X R .125

5.00

.55

1.00

ø .20ø .30 X 82°

R .56

R .601.48

3.80

.57

.2020°

.50

.57

Figure 8.147 Blade Base

.51

R .25

ø .375

1.42

1.37

2.08

2.39

2.33

2.38

2.12

1.23

.87

.12

95°

1.21

83°

.50 .45

2.11

1.08

1.42

1.25

2.37

2.71

2X ø .75

1.00

4X ø .31.75

1.11

2X ø .50

11°

R .50.50

2X R .50

R .50

Figure 8.145 Bar Hinge

.125

.690

.250

1.000

.094

.625

.750

.500

1.500

1.750

R .250

.375

1.7501.6251.060

.760

2.625

3.375.375

.625

.750

2.000

1.625

.500

Figure 8.144 Pump Base

1.77

4.08

.50

R .75

2X ø .375

2X R .50

2.00

.672.40

.50

1.00

1.50

.45

2.74

3.74

2.002.45

.67


Figure 8.143 Auger Support


.5008X ø .250

8X 45°

4.000

ø 4.3578R 1.000R .550

5°1.000

120°

4X ø .445

ø 2.500

2.3107

4X R 1.750

4X R .250

1.50

.1250

.3750

ø 4.8578R 1.803

3.00

4.000

Figure 8.148 Dryer Tube

ø 4.000

3X ø .500

3X 120°

R .875

ø .750

R 2.3029

R 1.1788

R 1.1117

.1218

ø 1.47441.375

.250

43°

.250.250

2.2723

3.7022

40°

ø 3.00

ø .750

.4913

.085

Figure 8.149 Index Adapter

(.52)

(2.23).18

.37

(R 1.11)

(R .70)

.76

R .09

VIEW A-A

39°

R 1.29

.39R .26BOTH SIDES

58°

.67

NOTE: ALL FILLETS & ROUNDS.09 U.O.S.

R .38

.46

ø 2.23RAISED .03ø 1.78.04 X 45°

2.23

.10

.75.95

1.601.70

4X R .36

2.18

2.78

2X ø .38

2X ø .10

2.401.91

.90

2.63

R 1.12BOTH SIDES

3.01

R .56BOTH SIDES

.19

.75

1.24

R .58

.95 1.57

ø .80

.20

.55

25°

25°

.14

3.49

35°

3.89

R 1.16

3.43

R 1.56

2.894.05

.52

R 1.11

R .70R .13

5.74

.61

CL

A

A

VIEW

Figure 8.150 Connecting Rod

.95

1.16

2.00

ø 1.08ø 1.54

.44

ø 4.36

4X ø .44

4X 90°

ø 3.41 B.C.

.54

1.00

8°

Figure 8.151 Retaining Cap

.62

ø 1.00

1.37

2X ø .50

2.001.00

.125

3.25

.50

ø 2.00

1.50

.64

.75

3.00

ø .50

1.37

Figure 8.152 Locating Block

1.10

.71

R 1.03

1.35

1.60

.125

.50

.125

1.08.31

.07

ø 2.25

.08

8 FINS

EQUALLY SPACED

R .03

.66

Figure 8.153 Spin Drive


METRIC

92

422

378

PROFILE A

R 36

18

R 18238

R 394

R 9

PROFILE A

16

206

Figure 8.157 Air Foil

1.56

3.06

1.53

.38

1.94

.728X ø .25ø .44 X 82°

2.50 2.00

ø 1.13

ø .621.13

2X R .25

2X ø .251.25

125°

51°

4.50

.38

.91

.88

2.69

.37

1.19

.25


1.25

Figure 8.158 Locating BaseFillets and Rounds R .09

1.30.26

1.43

ø .94

1.59.80

.54

1.782.86

.56

ø 1.31CENTERED

3.47

4.59

R .38

4X ø .29ø .56.192.72

99°

.47

.47

.38

Figure 8.159 Anchor Base

ø .65

1.43

1.63

R .53

.29

.98

.20

.57

.11

.33

2X ø .24

1.80

.90

.33

1.7

R .40

.49

ø .49

.815

.57

.30

Figure 8.156 Tool Pad

.54

8X ø .25

ø 1.60

ø 7.57

ø 1.00

.125

1.50

1.12

8X R .25

8X 27°.11

.34

1.00.50

Figure 8.154 Solar Mill

ø 2.50

2X ø 5.00OFFSET 90°AROUNDCENTRAL AXIS

ø 1.50.0625 X 19°

ø 2.19

ø 3.00

Figure 8.155 Spherical Spacer


1.60

2.00

ø 1.50

54°

.25

.19

ø .40

ø 5.88ø 1.38ø 1.63

5°4X ø .50

ø 5.46

2.241.50

.66

1.744.44

3.48

2.11

ø 1.60

1.99

.09

.88

.75

.37.48

Figure 8.161 Dryer Gear

.74

.73

2X R 2.83.25

ø .28

ø 1.10

ø 5.03

.25

32°6X ø .596X 60°

ø 2.52 B.C.

R 2.00

.13

.62

4X ø .284X 90°

ø 4.60 B.C.

Figure 8.160 Evaporator Cover

12X ø .15

12X 30°ø 2.55 B.C.

.17

.68

74°

ø .34.84

4X ø .37 X .42 LG

4X 90°ø 2.55 B.C.

15°

.17

ø 3.37ø 2.90

ø .86

ø 1.71

Figure 8.163 Relay Clip

45°

10°

4.10

1.43

3.45

.66

.87

.17

ø 1.07ø 1.34.443.48

6X ø .29

.59.80

.72

108°

R .31

2.614.75

5°

2.50

1.25

1.07

.32

Figure 8.162 Heater Clip

R 1.34

R .39

R .16

R .59

.73

R .39

.59

1.371.18

.10168°

1.35

.49.79

2.56

1.11

1.18

R .59

.42

1.36

1.00

R .25

Figure 8.165 Caster Mount

ø .375

1.500ø .500

ø .3751.50

.3125

.625

.0625

1.20

3X ø .125

3X 120°

ø 1.57

ø 2.50ø 2.00

ø .500

ø 1.00

Figure 8.164 Clip Release


.156 .250

.063

.375

2.500

.203

.250

.313.125.094

.375

.188

.313

.031

.125.094

.094

14°

.031

.062.125

.188

.125

VIEW A

.020

A

.250

Figure 8.168 Lens Clip

21.00

50.50

1.50 13.00

5.00

12.00

25.0018.50

ø 3.5

5.00

10.00

1.50

12.004.00

R 7.50

ø 3.50

4.00

METRIC

Figure 8.169 Strike Arm

127.00

147.00

4X R 10.00

9.90

10.00

9.15

8.30

25.004X ø 4.00

8.30

96.00

63.50

METRIC

THICKNESS 4

Figure 8.170 Offset Plate

17.0

17.0

8.13°

43.089.0102.0

41.0

8°

4X R 2.0

ø 12.0

ø 16.0

42.0

102.0

12.0

METRIC

21.0

Figure 8.171 Clamp Down

.625

.969

.313

1.250

R .625

ø .500

2.250

.563

1.876

.750

.750

.413

.563

Figure 8.166 Slide Base

ø .688

.500

1.125

.500

3.500

4.000

.500

1.000

.938

2.380

ø 1.375

2.000

.500

1.19

Figure 8.167 Retainer Clip


1.5625

ø .1875

R .1878

.2969

ø .687

.125.750

.5625

.0254

Figure 8.172 Shelf Stud

.500

.0486.125

1.00

1.9722

3.8602

58°

1.9423

.9262

1.1304

.3741

.9565

4.2505

.500

.500

.5557

.4374

R .300

ø 1.250ø .125

.100 THICK

.25

.4241

.7563

Figure 8.173 Manifold Plate

2.500

R .1093

.1184

.250

.8604

.3525R .1872

.4302R .230

Figure 8.174 Switch Clip

.5001.875

6.000

4.000

.250R .500

R .250

R .2506X ø .250

1.000

1.125

Figure 8.175 Protector

R .500

.500

.750

2.000 1.000ø .25

3.000

1.000

5.5002.500

R 1.000

.750

2X ø .500

.500

.500

Figure 8.176 Bearing Plate .75

1.50

BEND RADIUS

.0625

8.00

2.125R .625

ø .625.125

7.00.500

70°

.500

3.020

Figure 8.177 Angled Support


.250

1.00

.625

.500

6X ø .500ø .0625 X 45°

BOTH SIDES

.750

5.00

Figure 8.182 Grate

ø .2812.3749

1.7818

.2812

.1266

.1535

ø .3750ø .6633

ø .5482

ø .2500

.2812

Figure 8.183 Float Extension

.500

R 1.413

74°

4.000

1.000

8.000

9.00010.143

ø 1.250

1.661

.500 X .500 NECK

.625

2.206

ø 4.000

ø 4.500

Figure 8.180 Pump Base

.6966

8X ø .375ø .0625 X 45°

BOTH SIDES

R .0625

.1875

6.000

.5625

.4375

.7501.125

.375

.500

Figure 8.181 Burner Cap

2.250

R .125

ø .500

ø 1.250

2X ø .750

.250

1.375 1.625

2X R .625

.750

Figure 8.184 Drive Base

.313

.400

.125

ø .460

.060 GROOVE

.025

ø .250

6-32UNC-2B

.276

0.10 X 45°

Sø .500

Figure 8.178 Diffuser Knob

.156

.1715.188

.094

ø .563

ø .188

.031

.1095

ø .100.144

.078

Figure 8.179 Drive Collar

Chapter 8 Multiview Drawings - MHHE - McGraw Hill...

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