Engineering Drawing Course [Semo] FilMood

8/8/2019 Engineering Drawing Course [Semo] FilMood

1/127

PREPARED BY

Department of Engineering Production & MechanicalDesign

FACULTY OF ENGINEERING MANSOURA UNIVERSITY


2/127

CHAPTER ONE


3/127

Introduction

.

Codes of Practice .


4/127

DrawingInstruments

Drawing Board Drawing Pencils Drawing Paper TT-square

Triangle Compasses Box Ruler French Curves

ProtractorEraser Sellotape


5/127

Instruments


6/127

Instruments


7/127

Important Notes

.

T

T 0


8/127

Drawing Paper

A-series paper is used[Designation Size (mm)]

A0 841 x 1189 A1 594 x 841 A2 420 x 594

A3 297 x 420 A4 210 x 297

An A0 sheet has an area of 1m2 The sides are in the proportion 2 : 1 Do not assume that the paper has been cut correctly opposite sides may

not be parallel, and corners may not be exactly 90 degrees

Border (or margin)

The drawing should have a border of about 10 mm Space should be left for binding and hole-punching, if the drawing is to be

placed in a file


9/127

TypesofDrawing Pencils

Grade Hardness Use

7 B6 B

5 B

4 B3 B2 B

B

H BF

H2 H

3 H4 H

5 H

Softest

SoftMedium

MediumHard

Hardest

SpecialArtistic

Work

Sketching and rendering

In artistic work

Sketching,finishing, arrowhead,lettering,centre lines,dimension lines,

leaders, hatching lines.

Special graphic work.


10/127

ScalesofDrawing

Express as ratio drawing unit : real world unit

Enlargement scales: 50:1 20:1 10:1 5:1 2:1

Full size scale 1:1

Reduction scales 1:2 1:5 1:10 1:20 1:50

1:100 1:200 1:500 1:1000 1:2000 1:5000

1. Scales other than those above should only be used in exceptionalcircumstances (ensure that sensible numbers are used, e.g. 1:2500, not1:2384)

2. Check that the scale on the printed drawing is correct this is very

important (measure it)


11/127

Typesof Lines

OBJECT LINES Object lines depict the visible edges of an object. The

edges you would see looking at the object with yournaked eyes. They shown as dark, solid lines.

HIDDEN LINES Hidden lines depict invisible edges inside an object. Theedges you would not see looking at the object with yournaked eyes. They are shown as dashed lines.

CENTER LINES Center lines depict the center of any cylindrical-shapedobject whether it be a cylinder or hole. They are shown asa long line followed by a short line, followed by a longline.


12/127

Typesof Lines

Line Description..........

Continuous Thick

Continuous Thin

Continuous Freehand

Continuous Thin

With Zigzags

Dashed Thick

Dashed Thin

Chain Thin

Chain Thick

Chain Thin

Thick ends

Chain Thin

double-dashed


13/127

BASIC DIMENSIONG

: Extension Lines

Dimension Lines

Leaders Arrow heads

NotesSymbols


14/127

Lettering

.

. .


15/127

Drawing Table

The table should be at the right bottom of thedrawing sheet


16/127

Engineering Graphic

Animation

Becausegraphicalconceptsareoftendifficulttograsponastaticpage,Giesecke havedevelopedanimationsto bringthem tolife. Thissitefeaturesanimationsofconceptsthatappearineach ofthethree

Giesecke texts. Usetheseaidsto helpimproveyourability tothinkinthreedimensions.

Theanimationsutilizethe Flash plug-in. Ifyoudonothavethe Flash plug-in,pleaseclick heretodownloadit. All Flash movieswillopenanew browserwindow.

Giesecke on the Web


17/127

GEOMETRICAL

CONSTRUCTIONS

Refer to the Book for Different

Geometrical Constructions.


18/127

CHAPTER TWO


19/127

Sketching

1. Sketchingisa quickway of visualizingandsolvingadrawingproblem.Itisaneffectiveway ofcommunicatingwithallmembersofthedesignteam.

2. Therearespecialtechniquesforsketchinglines,

circles,andarcs. Thesetechniquesshouldbepracticedsothey becomesecondnature.

3. Moving yourthumbupordownthelengthofapencilatarmslengthisaneasy methodforestimatingproportionalsize.

4. Usingagridmakessketchinginproportionaneasy task. Gridpapercomesina variety oftypes,includingsquaregridandisometricgrid.


20/127

Sketching

1. Youcansketchcirclesby constructingasquareandlocatingthefourtangentpointswherethecircletouchesthesquare.

2. A sketchedlinedoesnotneedtolooklikeamechanicalline. Themaindistinctionbetweeninstrumentaldrawingandfreehandsketchingisthecharacterortechniqueofthelinework.

3. Freehandsketchesaremadetoproportion,butnotnecessarily toaparticularscale.

4. Notesanddimensionsareaddedtosketchesusinguppercaselettersdrawnby hand.


21/127

Sketching

Sketching is one of the primary means ofgraphic communication amongengineers. The ability to sketch is an

essential tool for all engineers assketching is used to convey originalideas from the engineer to the designerand from the designer to the drafter.

There are three types of sketches:-1.Pictorial2.Multiview3.Diagrammatic


22/127

Sketching

Line types are the same for sketching asfor formal drawings. There are variousshort cuts in sketching that can makeyour life easier:- A freehand sketch is adrawing in which all the proportions andlengths are judged by eye and all linesare drawn without the use of drawinginstruments the only tools being pencils,eraser and paper.


23/127

Sketching

The ability to sketch is a skill which isacquired through learning initially todraw freehand squares circles, ellipses

and curves. Circular curves must bedrawn with the ball of the hand inside thecurve and straight lines must be drawnby resting the weight of the hand on thebacks of the fingers as shown below.


24/127

Sketching

Axonometric ProjectionIn this type of projection the isometric view isusually used. Isometric projection is based on theprinciple that a cube representing the projection

axes will be rotated until its front face is 45 degreeto the frontal plane and then tipped forward todownward at an angle of 35.27degree. The resultingrotation displays all the faces equally.


25/127

Sketching

The viewing plane 1-2-3 is parallel to theprojection plane (image plane). This isan isometric view. In true isometricprojection, the three planes make equal

angles of 120o amongst themselves.Isometric sketches are constructedalong three axes, one vertical and theother two at angles of 30o to the

horizontal going both right and left. Alllines are drawn true length and areconsidered to be isometric lines.


26/127

Sketching

Representation of Circles in Isometric ProjectionThere are several ways a circle can beconstructed in isometric projection.

a) SketchSketch an enclosing isometric square.

Sketch bisecting lines, at points of intersection ofthis lines with the square sketch tangential arcs.Sketch remaining parts of the ellipse.


27/127

Sketching

b) Ordinates MethodDraw a circle and divide into equal numberof ordinates.Draw isometric square.Transfer all ordinates from 1 to 2.

Join the plotted points to form an isometriccircle


28/127

Sketching

The mentioned method may be adapted forany irregular shape.


29/127


30/127

DIMENSIONING

Dimensioning Practice (Terms)Dimensions

A numeric value expressed in appropriate unitsof measure and indicated on a drawing and inother documents along with lines, symbols, andnotes to define the size or geometriccharacteristic, or both, of a part or part feature.Example: 12.875 (in.), 25 (mm), etc.Reference Dimension

A dimension, usually without tolerance used forinformation only. It is considered auxiliary

information and does not govern Production orinspection operations. A reference dimensionrepeats a dimension or size already given or itderived from other values shown on the drawingor related drawing. Reference dimensions areenclosed in parenthesis eg (23.50).


31/127

DIMENSIONINGDatum

The origin from which the location or geometriccharacteristics of a part are established. Thecorrect identification of datum on a componentand the related dimensioning can be relateddirectly to the methods of manufacturing e.g., CNCco-coordinators for machining features, indicatingwork holding features.

Feature

The general term applied to a physical portion of apart, e.g. a surface, hole or slot.

Datum feature

A geometric feature of a part that is used toestablish a datum. Example: a point, line, surface,hole, etc.


32/127

DIMENSIONINGActual Size

The measured size of the feature.Limits of size

The specified maximum and minimum limits of a feature.Tolerance

The total amount by which a specific dimension is permitted

to vary. The tolerance is the difference between themaximum and minimum limits.


33/127

DIMENSIONING


34/127

TypesofDimensioning

ParallelDimensioning Parallel dimensioning consists of several

dimensions originating from oneprojection line.

SuperimposedRunningDimensions

Superimposed running dimensioningsimplifies parallel dimensions in order toreduce the space used on a drawing. Ingeneral all other dimension lines arebroken. The dimension note can appearabove the dimension line or in-line withthe projection line

Ch

ainD

imensioning Chains of dimension should only beused if the function of the object won't beaffected by the accumulation of thetolerances. (A tolerance is an indicationof the accuracy the product has to bemade to


35/127

TypesofDimensioning

CombinedDimensions A combined dimension uses both chain

and parallel dimensioning.

Dimensioningby Co-ordinates

Two sets of superimposed runningdimensions running at right angles can beused with any features which need theircentre points defined, such as holes.

Dimensioning SmallFeatures

When dimensioning small features, placingthe dimension arrow between projectionlines may create a drawing which is difficultto read. In order to clarify dimensions onsmall features any of the above methodscan be used.


36/127

TypesofDimensioning

For Circles

For Radii

For Holes


37/127

CHAPTER THREE


38/127

ISOMETRIC DRAWINGIsometric drawing is another way of presentingdesigns/drawings in three dimensions. The example oppositehas been drawn with a 30 degree set square. Designs arealways drawn at 30 degrees in isometric projection


39/127

ISOMETRIC DRAWINGSIMPLEEXERCISE

1. Draw two basic 30 degree guidelines, one to the left andone to the right, plus a vertical guideline in the centre ofthe drawing. In this example three edges of the cubehave been drawn over the guidelines (they are slightlydarker).

2. Draw guidelines to help you start constructing the left

and right sides of the cube. Remember to use a 30degree set square for the 'angled' lines.3. Draw the two sides in place. They should be darker than

the faint guidelines.4. Complete the top of the cube by projecting lines with the

30 degree set square as shown opposite.

5. Complete the top of the cube by projecting lines with the30 degree set square as shown opposite.


40/127

ISOMETRIC DRAWING


41/127

ISOMETRIC CIRCLES AND

CYLINDERSDrawing a basic isometric shape such as cubecan be difficult the first time you attempt todraw it using a T-Square and 30 degree SetSquare. However, after a few attempts the

technique for drawing them can be masteredquite easily. On the other hand - isometriccircles and cylinders are more difficult anddrawing them requires practice.

The sequence for drawing both is shown below:


42/127


CYLINDERS


43/127


CYLINDERS

1. Draw the original circle with a compass and enclose it in abox. Add vertical and horizontal guidelines

2. Number the vertical lines (these are called 'ordinate lines')

as shown on the diagram opposite.3. Draw the grid in isometric using a 30 degree set square,

being careful to use the same measurements as theoriginal grid which surrounds the circle.

4. To draw the circle in isometric projection simply measureeach distance down each vertical line on the normal gridand transfer it to the isometric grid. On the diagramsopposite - distance 'x' on guideline 3 has been transferredto the isometric grid. This is repeated for each of theguidelines 1,2, and 4.

5. Continue around the isometric circle 'plotting' transferringdistances from the original grid to the isometric grid - until


44/127


CYLINDERS


45/127

PRODUCING A CYLINDER

SHAPE IN ISOMETRIC

1. Having successfully drawn theisometric circle developing it furtherto change it into a cylinder isrelatively easy. Draw 30 degree

guidelines out from the isometriccircle as shown in the diagram.2. Measure the distance representing

the 'thickness' of the cylinder along

each 30 degree guideline. Startdrawing a curve through each of thepoints.

3. Draw the curve through each of the

points to produce the final cylinder


46/127

PRODUCING A CYLINDER

SHAPE IN ISOMETRIC


47/127

ISOMETRIC CUBES


48/127

ISOMETRIC CUBE EXERCISE

Using a basic isometric cube with 25mmsides or less, build up a shape similar tothe one seen below. Remember, using a

30 degree set square is vital for thisexercise. The only other lines are verticallines. If you feel confident with drawing inisometric use blank paper otherwise use

isometric paper (seen below). This paperhas 30 degree lines and vertical linesalready printed on it (similar to graphpaper).


49/127

ISOMETRIC CUBE

EXERCISE


50/127

CHAPTER FOUR


51/127


52/127

Possible Views

Top

Front Right SideLeft Side

Bottom

Back


53/127

Selectionof Views

Not all 6 views have to beshown in an orthographicprojection drawing.

Details are repeated in the top

and bottom, right and left, andthe front and back views.


54/127

Orthographic Projection

The aim of an engineering drawing is toconvey all the necessary information ofhow to make the part to the manufacturing

department. For most parts, theinformation cannot be conveyed in asingle view. Rather than using severalsheets of paper with different views of the

part, several views can be combined on asingle drawing using one of the twoavailable projection systems, first angle,and third angle projection.


55/127

OrthographicDrawing

Orthographicdrawingsaretheresultofprojectingtheimageofathree-dimensionalobjectontooneofsixstandardplanesofprojection. Theplanesofprojectionintersecteachotheratfoldlines. Thesixstandardplanesofprojectionareoftenthoughtofasa "glassbox."

Each viewinanorthographicprojectionis

alignedwithanadjacent view. Theprincipalviewsmostoftenusedaretop,front,andrightside.


56/127


57/127

Whatisanorthographic

Projection? An orthographic projection is

a multi-view drawing used toshow all of the features of an

object.

Different views are set up in asystematic way to mentallyconnect them together.


58/127

Objectives

Identify an orthographic projection. Select the best views to describe an

object.

Identify objects from anorthographic projection drawing. Identify the visualization rules of an

orthographic projection drawing.


59/127

Visualization

Visualization is the ability to forma mental picture of what an objectis going to look like when its

completed.

You must compare the top, front,

sides, back and bottom views tosee what shapes the objects havein common.


60/127

Visualization Rules

1. Scan briefly all views shown. 2. Study the front view for shape

description.

3. Move from view to view to findsimilar lines, surfaces, and shapes.

4. Study one feature at a time and

begin to put the shapes together toform the 3 dimensional shape of theobject.


61/127


62/127

ProjectionSystems

Oneofthetwoavailableprojectionsystems, firstangle,and thirdangle

projection.


63/127

OrthographicDrawing

Tohelpprojectorverify surfaces youcanlabelthemwithletters,andthecornersof

surfacescanbelabeledwithnumbers.

Therearenormal,inclined,andoblique

surfaces. Normalsurfacesappeartruesizeinoneprincipal viewandasanedgeinthe

othertwoprincipal views.Inclined

surfacesappearasanedge viewinoneof

thethreeprincipal views. Obliquesurfaces

donotappearinedge viewinany oftheprincipal views.


64/127



65/127



66/127

Projectioninthree views

First angle projection


67/127

The Projectionof Views

Must be able to visualize theobject as a whole and be ableto mentally put the views

together. Views are projected at right

angles (90 Deg) to each other.

There are 6 different viewspossible in an orthographicprojection.


68/127

Summary

The purpose of an orthographicprojection is to show an object inits true shape and size.

The different views in anorthographic projection are

projected at 90 degrees to eachother.


69/127

Summary

Four rules should be consideredwhen selecting which views touse.

Visualization involves being ableto form a mental picture of whatthe object is to look like.

Use the 4 visualization rules tohelp form a mental picture of theobject.


70/127

Summary Questions

What is an orthographic projection? What are the proper locations of all six views

that can be produced in an orthographicprojection?

Out of the six possible views, why do we usuallyonly select 3?

What 4 rules must you follow when selecting theviews for an orthographic projection?

What is meant by visualization of an object? What 4 rules are used in the visualization

process?


71/127

CHAPTER FIVE

S C O G


72/127

SECTIONING

Sectional View in a single planeThe example shows a simple singleplane sectional view where object iscut in half by the cutting plane. Thecutting plane is indicated on adrawing using the line style used for

centre lines, but with a thick lineindicating the end of lines and anychange in the direction of the cuttingplane. The direction of the view isindicated by arrows with a referenceletter. The example shows asectional view of the cutting plane A- A.


73/127

SECTIONING

Sectional View intwo planesIt is possible for thecutting plane to

change directions, tominimise on thenumber of sectionalviews required tocapture the necessarydetail. The example

shows a pipe beingcut by two parallelplanes. The sketchshows where theobject is cut.


74/127

SECTIONING

Half Sectional views

Half sections arecommonly used toshow both the internaland outside view ofsymmetrical objects


75/127

SECTIONING

Part Sectional views

It is common practice to section a part of anobject when only small areas need to be

sectioned to indicate the important details.The figure shows a part sectional view toindicate a through-hole in a plate. Notice thatthe line indicating the end of the section is a

thin continuous line.


76/127

SECTIONING

HALFVIEWSAND PARTIAL

VIEWS

Half Views and Partial

views are used to simplysave space when half of,or portion of a view is not

needed or is redundant.


77/127


78/127

SECTIONING

SECTIONVIEWS

Section views are used to get rid of the confusing

hidden lines:


79/127

SECTIONINGSECTIONVIEWS

Wheretheobjectiscutiscalledthecuttingplaneandthedirectionofviewisdepicted by arrows. TheSECTION A-A noteisforuseiftheviewisonadifferentpagefrom the mainviews.The materialthatissupposedly cutis "Hatched"with patterns. Thepatternsoftendepicttheactualmaterialoftheobject.


80/127

SECTIONINGThepatternsoftendepicttheactual materialoftheobjectareasshown


81/127

SECTIONINGFULL SECTIONS

Fullsectionviewscutalltheway acrosstheobject. FullSection Viewscan beplacedonthesamepageoronanotherpage. The Cutting Planeand Arrowsalways aredisplayed.


82/127

C O G


83/127

SECTIONINGOFFSET SECTIONS

Offset Section ViewsarelikefullsectionviewsexceptthattheCutting Plane bendstofollowcertainfeaturesinsidetheobject.

SECTIONING


84/127

SECTIONING

REVOLVED VIEWSRevolved Viewsareashortcutway toshowasectionviewthatshowstheinternal shapeofanobjectwithoutcreatingacompletely separatesectionview. Thecuttingplanepassesthrough theobjectatthedesiredlocationandisrevolved,inplace,toshowthesectionview. Revolved Viewscan beinsidetheregularview:Thefollowingslideillustratessomeoftheserevolvedsections

SECTIONING


85/127

SECTIONING

REVOLVED VIEWS

SECTIONING


86/127

SECTIONING

BROKEN OUT (LOCAL)SECTIONS

Brokenout Sectionsareanothersectioning

shortcut.Itisaway to makeasectionviewofonly aspecificandusually small

area.

SECTIONING


87/127

SECTIONING

CONVENTIONAL BREAKSConventionalBreaksareaway ofdepictingavery longobjectwithoutshowingtheentirelength. Itisoftenusedforobjectslikerods,tubing/pipingorwoodenobjects


88/127

HATCHING

On sections and sectional views solidarea should be hatched to indicate thisfact. Hatching is drawn with a thin

continuous line, equally spaced(preferably about 4mm apart, thoughnever less than 1mm) and preferably atan angle of 45 degrees


89/127

HATCHING

Hatching One, Two and Multi Objects


90/127

HATCHING

Hatching Thin SectionsSometimes, it is difficult tohatch very thin sections. To

emphasise solid wall thewalls can be filled in. Thisshould only be used whenthe wall thickness size is

less than 1mm


91/127

HATCHING

Hatching LargeSections

When hatching large

areas in order to aidreadability, the hatchingcan be limited to the areanear the edges of the

part.


92/127

HATCHING

Which Sectional View?Before proceeding, consider the diagrams belowand select the correct sectional view.


93/127

Drawingthreadedparts

Drawing Conventions

Threads are drawnwith thin lines as

shown. When drawnfrom end-on, athreaded section isindicated by a broken

circle drawn using athin line.


94/127

Drawingthreadedparts

Frequently a threaded sectionwill need to be shown inside apart. The two illustrations

demonstrate two methods ofdrawing a threaded section.Note the conventions. Thehidden detail is drawn as athin dashed line. The sectionalview uses both thick and thinline with the hatching carryingon to the very edges of theobject

CHAPTER SIX


95/127

CHAPTER SIX


96/127

Steel Constructions


97/127

StandardSteelSections


98/127



99/127



100/127



101/127


St l C ti


102/127

Steel Connections

St l C ti


103/127

Steel Connections

St l C ti


104/127

Steel Connections

St l C ti


105/127

Steel Connections

St l C ti


106/127

Steel Connections

St l C ti


107/127

Steel Connections


108/127

St l C ti


109/127

Steel Connections

Steel Connections


110/127

Steel Connections

Steel Connections


111/127

Steel Connections


112/127

Steel Connections


113/127

Steel Connections

Steel Connections


114/127

Steel Connections

CHAPTER SEVEN


115/127

CHAPTER SEVEN

AUTOCAD


116/127

AUTOCADStarting AutoCADStart AutoCAD by clickingontheWindowsStart button(bottom left),then movethe mousetoPrograms thenCAD and Modelling then "AutoCAD ArchitecturalDesktop2" andclickonAutoCAD Architectural Desktop 2.

A dialoggivingvariousstartupoptionswill bedisplayed.Selectthesecondoption: "Startfrom Scratch" andclickOK.

Once AutoCAD hasloaded, movethe mousearounduntilyouseeacrosshaircursor. The AutoCADwindow hasanumberofimportantfeatures:


117/127

AUTOCAD


118/127

AUTOCADCommand Entry

Typically therearethreewaysofgivingacommand:

Typethecommandusingthekeyboard-thecommandisdisplayedinthecommandarea.

Selectthecommandfrom a menu.

Selectthecommand'siconfrom atoolbar.

AUTOCAD


119/127

AUTOCAD

Draw a RectangleSelectRectangle (ortyperectang), then

type: 15,15

Thetexttypedis displayedinthecommandarea atthe bottom of AutoCAD's window.

415,315(These are absolutecartesiancoordinates)

AUTOCAD


120/127

AUTOCADSaving a Drawing

Notethatif you typeSAVE , you actually get"Save As"!.The quickestwayto saveis to press Ctrl-S- this

is the same as "qsave".Selectthe

Saveicon fromthe standardtoolbar.

Thedrawing has notbeen savedbefore, soAutoCAD willdisplaytheSAVE ASdialog box,

select

the

approp

riate

Drive

and

Direct

ory,

typ

ethedrawingname, andthen select"OK".

AUTOCAD


121/127

AUTOCADDraw some Lines

InsteadofLINE, you can also type:L - which is a short-cut.

TypeLINEMovethecrosshairto nearthe bottom-leftoftherectangle andclickthe leftmouse button, then movethecrosshairto thetop-rightoftherectangle andagainclickthe leftmouse button.

Rememberthis!If you press Enter afteryou finish acommand, thecommandis re-issued. Press Enter toterminatethecommand, andthen press Enteragaintore-startthecommand!

Draw a line from thetop-leftto the bottom-rightofthe

rectangle, andthen press Enterto endthecommand.This will savethedrawing andexitAutoCAD.type:QUITYou will be promptedto savethechanges you'vemade - clickOK.

AUTOCAD


122/127

AUTOCADDraw a "Diamond"

The "polyline" usedbelowis usedto create a sequence ofjoined line segments, which become one object.

Usingthe "line"commandeach line segmentis a separateobject.SelectPolyline (ortype:pline ) andthentype:

absolutecoordinate 215,15absolutecartesiancoordinate @212


123/127

AUTOCADSnap ModesItis often usefulto be ableto draw something from (for

example) theendof anothershape. AutoCAD has a large

selection of "snap modes" forthis purpose. The most

commonly usedsnap modes are "Endpoint" (which snaps to

theendofthe selectedgraphics entity) and "Intersection"(which snaps to theintersection oftwo graphics entities).

The objectsnap modes caneitherbetypedortheycan be

selected from the standardtoolbar or from the snap toolbar:

AUTOCAD


124/127

AUTOCADDraw an Arc

SelectArc(ortypeARC), then selectthemidpoint snapmode (ortype:MID ) andselectthe leftside ofthe bottom of

the "diamond" polyline you drew before. Then usethe

midpointsnap to enterpoints ontherightside atthe bottom

and

then

thetop of

the

polyline

(see

figu

re).

AUTOCAD


125/127

AUTOCADDraw this exercise

Lastly, I want youtodrawarectangleinthediamondshape,anotherdiamondinsidethatrectangle,acircleinsidethatdiamondanda horizontalandverticallinealsoinsidethelastdiamond (seefigure) ! Each shapeshouldtouch theMidpointsofthepreviousshape...


126/127


127/127

Documents

Engineering Drawing Course [Semo] FilMood