2 Sketching

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MCE216L EngineeringMCE216L Engineering

Drawing and WorkshopDrawing and WorkshopLecture #2Lecture #2

Eng. Rami AliEng. Rami AliFall 2015Fall 2015



1.1. SKETC!"SKETC!"

2. $%&'ECT!&"S 2. $%&'ECT!&"S (. &%T&%)$!C(. &%T&%)$!C

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1.1.

SKETC!"SKETC!"



*reehand Sketching*reehand SketchingFreehand sketches are a he+p,u+ wa- to organie -our

thoughts and record ideas. The- pro/ide a 0uick +owcostwa- to e3p+ore /arious so+utions to design pro4+e5s sothat the 4est choices can4e 5ade.



The following are important skills to keep in mind forsketches

And drawings:

1.Accuracy. "o drawing is use,u+ un+ess it shows thein,or5ation correct+-.

2. Speed . Ti5e is 5one- in industr-. Work s5arter and +earn

to use techni0ues to speed up -our sketching and C)D drawings whi+e sti++ producing neat accurate resu+ts.

(. Legibility. ) drawing is a 5eans o, co55unicating with others so it 5ust 4e c+ear and +egi4+e. i/e attention todetai+s.

Things that 5a- see5 pick- and s5a++ as -ou are drawing 5a- 4e signicant and sa/e 5one- or e/en +i/es when the product is 4ui+t.

7. Neatness. !, a drawing is to 4e accurate and +egi4+e it 5ust a+so 4e c+ean.



Drawing 8oca4u+ar-Drawing 8oca4u+ar-

• Drawing Lines

• Lettering

• Measure5ent S-ste5s

• Sca+e

• Tit+e 9+ocks

A B C

Tit+e 9+ock

55!nch



)L$)9ET &* L!"ES)L$)9ET &* L!"ES



)L$)9ET &* L!"ES)L$)9ET &* L!"ES

& S



)L$)9ET &* L!"ES)L$)9ET &* L!"ES



)L$)9ET &* L!"ES)L$)9ET &* L!"ES



)L$)9ET &* L!"ES)L$)9ET &* L!"ES



)L$)9ET &* L!"ES)L$)9ET &* L!"ES



)L$)9ET &* L!"ES)L$)9ET &* L!"ES

Thick and Thin Drawing Lines

*reehand +ine techni0ue

Line st-+es



*%EE)"D L!"ES*%EE)"D L!"ES The 5ain di:erence 4etween an instru5ent or C)D drawing and afreehand sketch is in the appearance o, the +ines. ) good ,reehand

+ine is not e3pected to 4e precise+- straight or e3act+- uni,or5 as is aC)D or instru5entdrawn +ine. *reehand +ines show ,reedo5 and/ariet-.

Freehand construction lines are very light, rough

lines. All other lines should be dark and clean.



ood and $oor Techni0ueood and $oor Techni0ue

*%EE)"D L!"ES*%EE)"D L!"ES



SKETC!" ST%)!T L!"ESSKETC!" ST%)!T L!"ESMost of the lines in an average sketch are straightlines. With

practice, your straight lines will naturally improve,ut theseasics may help you improve !uickly.

; o+d -our penci+ natura++- a4out 1< 4ack ,ro5 the point and appro3i5ate+- at a right ang+e to the +ine to 4e

drawn.

; Draw horionta+ +ines ,ro5 +e,t to right with a ,ree and eas- wrist and ar5 5o/e5ent.

; Draw /ertica+ +ines downward with nger and wrist 5o/e5ents.



ST%)!T L!"E TipsST%)!T L!"E Tips



SKETC!" C!%CLESSKETC!" C!%CLES



ME)S=%EME"T S>STEMSME)S=%EME"T S>STEMS

=.S. Custo5ar- =nits

The Metric S-ste5

Dua+Di5ensioned



D%)W!" SC)LED%)W!" SC)LEDrawing scale is the reduction or en+arge5ent o, the

drawn o4?ect re+ati/e to the rea+ o4?ect

%educed and En+arged Sca+e. Many drawings must be shown at reducedscale for the object to t on the paper.





S$EC!*>!" TE SC)LE &" )S$EC!*>!" TE SC)LE &" )

D%)W!"D%)W!"

List the predo5inant drawing sca+e in thetit+e4+ock. @Courtes- o, D-no?et %esearch!nc.A

*or a part that is shownon the paper at ha+, itsactua+ sie the sca+e is

+isted in one o, thesethree wa-sB

SC)LEB 1B2SC)LEB 12SC)LEB .



2. $%&'ECT!&"S2. $%&'ECT!&"S



$%&'ECT!&"S$%&'ECT!&"S

To 5ake and interpret drawings -ou need to know how tocreate

pro?ections and understand the standard arrange5ent o,/iews.

>ou a+so need to 4e ,a5i+iar with the geo5etr- o, so+id o4?ectsand 4e a4+e to /isua+ie a (D o4?ect that is represented in a 2Dsketch or drawing.





Edges and 8erticesEdges and 8ertices

dges

)n edge o, the so+id is ,or5ed wheretwo sur,aces intersect. Edges arerepresented in drawings 4- /isi4+e orhidden +ines.

!ertices) /erte3 @p+ura+ /erticesA o, a so+id

is ,or5ed where three or 5oresur,aces intersect..

Points and Lines) point is used to represent a +ocation in

space 4ut has no width height or depth.



&"E8!EW D%)W!"S&"E8!EW D%)W!"S*re0uent+- a sing+e /iew supp+e5ented 4- notes anddi5ensionsis enough in,or5ation to descri4e the shape o, a re+ati/e+-si5p+e o4?ect.

"ote how thickness o, the 5ateria+ is gi/en as F.2 9%)SSG So an additiona+ /iew is not needed to di5ensiona++- gi/e the 5ateria+ thickness.



$!CT&%!)L SKETC!"$!CT&%!)L SKETC!") pictorial sketch represents a "D ob#ect on a $D sheet o% paper 4- orienting the o4?ect so -ou can see its width height and depthin a sing+e /iew.



Graphical projection is a protocol by which an image of an three-dimensional object is projected onto a planar srface withot theaid of mathematical calclation! sed in technical drawing.

"he projection is achie#ed by the se of imaginary projectors and projection plane.

$%&'ECT!&"S$%&'ECT!&"S



$%&'ECT!&"S$%&'ECT!&"S9ehind e/er- 2D drawing o, an o4?ect is a space re+ationshipin/o+/ing the o4?ect and three imagined! things"

1. The o4ser/erHs e-e or station point

2. The p+ane o, pro?ection

(. The pro?ectors @a+so ca++ed /isua+

ra-s or +ines o, sightA.$erspecti/e $ro?ection

$ara++e+ $ro?ection

T pes o, $ro?ectionsT-pes o, $ro?ections



T-pes o, $ro?ections T-pes o, $ro?ections There are two 5ain t-pes o, pro?ectionB perspective and parallel . These are 4roken down into su4t-pes as shown4e+owB

$ ? ti M th d$ ? ti M th d



$ro?ection Methods$ro?ection Methods

The ,our principa+t-pes o,pro?ectionsB

a Mu+ti/iew 4 )3ono5etric c &4+i0ue d $erspecti/e



(. &%T&%)$!C(. &%T&%)$!C

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@Mu+ti8iewsA@Mu+ti8iewsA



8iews o, &4?ects or8iews o, &4?ects or

Multi#iewsMulti#iews) s-ste5 o, /iews or pro?ections. Each /iew pro/ides certain denitein,or5ation. *or e3a5p+e a ,ront /iew shows the true shape and sie o,

sur,aces that are para++e+ to the ,ront o, the o4?ect.







Th Si S d d 8iTh Si St d d 8i



The Si3 Standard 8iews The Si3 Standard 8iews)n- o4?ect can 4e /iewed ,ro5 si3 5utua++-perpendicu+ar directions



%e/o+/ing the &4?ect to%e/o+/ing the &4?ect to

$roduce 8iews$roduce 8iews



$rincipa+ Di5ensions$rincipa+ Di5ensions The three principa+ di5ensions o, an o4?ect are width heightand depth.

• The ,ront /iew shows on+- the height andwidth o, the o4?ect and not the depth.

• !n ,act an- principa+ /iew o, a (D o4?ect showson+- two o, the three principa+ di5ensionsI the

third is ,ound• in an ad?acent /iew.

• eight is shown in the rear +e,tside ,rontand rightside /iews.

• Width is shown in the rear top ,ront and4otto5 /iews.

• Depth is shown in the +e,tside top rightside• and 4otto5 /iews.

$ ? ti M th d$ ? ti M th d



$ro?ection Method$ro?ection Method

$ro?ection o, an &4?ect

The out+ine on the p+ane o, pro?ection shows how the o4?ect appears to theo4ser/er. !n orthographic pro?ection ra-s @or pro?ectorsA ,ro5 a++ points onthe edges or contours o, the o4?ect e3tend para++e+ to each other and

perpendicu+ar to the p+ane o, pro?ection. The word orthographic 5eans atright ang+es.G



orionta+ and $ro+eorionta+ and $ro+e

$ro?ection $+anes$ro?ection $+anesSpecic na5es are gi/en to the p+anes o, pro?ection. The ,ront

/iew is pro?ected to the ,ronta+ p+ane. The top /iew is pro?ected tothe horionta+ p+ane. The side /iew is pro?ected to the pro+ep+ane.

Th + 9Th + 9



The +ass 9o3 The +ass 9o3&ne wa- to understand the standard arrange5ent o, /iews on thesheet o, paper is to en/ision a glass bo&.

!, p+anes o, pro?ection were p+aced para++e+ to each principa+ ,ace o, theo4?ect the- wou+d ,or5 a 4o3.

=n,o+ding the +ass 9o3=n o ng t e ass 9o3



=n,o+ding the +ass 9o3=n o ng t e ass 9o3

To organie the /iews o, a (D o4?ect on a Jat sheet o, paperi5agine the si3 p+anes o, the g+ass 4o3 4eing un,o+ded to +ie Jat.

"ote the si3 standard/iews @,ront rear top4otto5 right side +e,tsideA.

Th + 9 = , +d dTh + 9 = , +d d



The +ass 9o3 =n,o+ded The +ass 9o3 =n,o+dedLines e3tend around the g+ass 4o3 ,ro5 one /iew to another on thep+anes o, pro?ection. These are the pro?ectors ,ro5 a point in one

/iew to the sa5e point in another /iew.

h & h hi ? iTh & th hi $ ? ti



The &rthographic $ro?ection The &rthographic $ro?ection The ,ront top and rightside /iews o, the o4?ect shown nowwithout the %olding lines.

" 8i"ecessar- 8iews



"ecessar- 8iews"ecessar- 8iews

The top ,ront and rightside /iews

arranged together are ca++ed thethree regular views becausethe- are the /iews 5ost ,re0uent+-used.

A sketch or drawing should contain only the views neededto clearly and completely describe the object.

T 8iTwo 8iews



Two 8iews Two 8iewsMan- o4?ects need on+- two /iews to c+ear+- descri4e their shape. !,an o4?ect re0uires on+- two /iews and the +e,tside and rightside

/iews show the o4?ect e0ua++- we++ use the rightside /iew.

&ne 8ie&ne 8iew



&ne8iew&ne8iew&,ten a sing+e /iew supp+e5ented 4- a note or 4- +ettereds-54o+s is

Enough.

Choice o, *ront 8iewChoice o, *ront 8iew



Choice o, *ront 8iewChoice o, *ront 8iew

The /iew chosen ,or the front view in this case is the side not thefront o, the auto5o4i+e.

$osition o, the Side 8iew$osition o, the Side 8iew



$osition o, the Side 8iew$osition o, the Side 8iewSo5eti5es drawing three /iews using the con/entiona+arrange5ent wastes space.

idden Linesidden Lines



idden Linesidden Lines Thick dark +ines represent ,eatures o, the o4?ect that are direct+-/isi4+e. Dashed +ines represent ,eatures that wou+d 4e hidden 4ehindother sur,aces.

Center+inesCenter+ines



Center+inesCenter+ines'he centerline pattern is used to(

; show the a3is o, s-55etr- ,or a ,eature or part; indicate a path o, 5otion; show the +ocation ,or 4o+t circ+es and other circu+arpatterns

The center+ine pattern

is co5posed o, threedashesB one +ong dashon each end with ashort dash in the5idd+e.

C C & S$%ECEDE"CE &* L!"ES



$%ECEDE"CE &* L!"ES$%ECEDE"CE &* L!"ES

) /isi4+e +ine a+wa-s takes precedence o/er

and co/ers up a center+ine or a hidden +inewhen the- coincide in a /iew @) and 9A.

) hidden +ine takes

precedence o/er acenter+ine @CA.

Center+ines continuedCenter+ines continued



Center+ines continuedCenter+ines continuedCenter+ines @s-54o+B A are used to indicate s-55etrica+ a3es o,o4?ects or ,eatures 4o+t circ+es and paths o, 5otion.



$RA%"&%E %'A(( )*R+ , 1



$RA%"&%E %'A(( )*R+ , 1

Ee.1 As Eample/ raw the three orthographic mlti#iews forthe following part



Ee.2 raw the three orthographic mlti#iews for the following parts

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