Upload
fawad-hassan
View
32
Download
2
Embed Size (px)
DESCRIPTION
drawing is very important in order to represents the visual drawing
Citation preview
EngineeringDrawings
AshortseriesoflecturesonEngineeringDrawingasPartofENGG1960:IntroductiontoBiomedicalEngineeringByPaulBriozzo
WhatisanEngineeringDrawing?AnEngineeringDrawingisatechnical(notartistic)drawingwhichclearlydefinesandcommunicatesadesigntootherinterestedparties.
Otherpartiesmayhaveaninterestindesigncollaboration,procurement/purchasing,costing,manufacturing,qualitycontrol,marketing,handling/packaging.
WhydoweneedtoknowaboutEngineeringDrawings?
Toallowourdesignstodevelopfromathoughtorconcepttoadesign/sketchonpaper.
Toenableustocommunicateourdesigns/sketchestocolleaguesforreview.
Toconvertoursketches/designsintolayoutdrawingswhichshowhowourideaslinkuptoexistinginfrastructures.
Toincludeourdesign/sketchesaspartofaproposalforclient/managementapprovalandreview.
ToprovideManufacturerswithworkingEngineeringDrawingsbasedfromouroriginaldesigns/sketches.
PictorialFreehand
ExamplesofLayoutDrawings
CollapsibleCanoeOutriggerDesignProject,1998UndergraduateDesignProjectundertheLeadershipofA/Prof.HarryLipkin,GeorgiaTechUniversity
LunarModuleLandingGearPlans,NASA,1969
ExamplesofLayoutDrawings
ProposalDrawing
EngineeringdrawingbyHarryC.Shoaf (SpaceTaskGroupEngineeringDivision)oftheproposedlunarlandertobeusedwithanadvancedversionoftheMercuryspacecraft.(Shoaf,Drawing,Nov.15,1961.)
Surveyor1,1966LunarLander,1969
EngineeringDrawing
DetailDrawing(FinishDrawing)ofConnectingRod,M.Jacek 1973
TheHistoryofEngineeringDrawingFreeHandSketches LeonardoDaVinci 1500AD
Sforzamonument
Anatomicalstudyofthearmc1510
Rhombicuboctahedron
Designforaflyingmachinec1488
GraphicalProjectionsProjections
Axonometric/Isometric Orthographic
Oblique
ParallelProjectionPerspective
Orthogonal
1st Angle 2nd Angle 3rd Angle 4th Angle
Perspective
Staircase twopointperspective Cube twopointperspective
Cube onepointperspective Cube twopointperspective Cube twopointperspective
MethodandRulesofProjections
Selectaviewfromthemostadvantageousposition. Observeoverallstructurefirst. Note:parallelism,proportionsandalignment.
Method
RulesofProjection Objectviewedfrom. Parallellinesremainparallel. Proportionsremainunchanged. Circlesarealwaysellipseswiththemajoraxisofellipse
perpendiculartothepolaraxisofcircle. Transformationof90 angles.
ParallelProjection
Axonometric/Isometric Orthographic
Oblique
ParallelProjection
Orthogonal
1st Angle 2nd Angle 3rd Angle 4th Angle
ObliqueProjection
Cavalierviewsarenotpreferred.Theyshowlineswhichrepresentthedepthoftheobjectasbeingdisproportionallylong.Eventhoughtheyareparalleltoeachother,depthlinesappeartodivergeawayfromeachother.
CabinetviewsarepreferredoverCavalier.Theissueofdepthdisproportionalityanddivergenceissomewhateliminatedbyhalvingthedepthdimension.
ObliqueProjectionCavalierandCabinetProjections
Cavalier Cabinet
ObliqueProjection4BasicRules
1.Placetheobjectsothattheviewwiththemostdetailisparalleltothepictureplane.
2.Placetheobjectsothatthelongestdimensionrunshorizontallyacrossthesheet.
ObliqueProjection4BasicRules
3.Insomecasesthepreviousrulesconflict,andwhenthisisso,Rule1haspreferenceastheadvantagegainedbyhavingtheirregularfacewithoutdistortionisgreaterthanthatgainedbyobservingRule2.
4.Decisionsaboutviewinganobjectinobliqueprojectionshouldaimtoshowtheobjectsothatitsshapeismostclearlypresentedandisconducivetoshowingitsdimensions.
AxonometricProjection
ProjectionlinesareperpendiculartoProjectionPlane. PrincipalaxesinclinedtoProjectionPlane. Isometric(EqualScaling) Dimetric Trimetric
IsometricDimetric
Orthographic
Orthogonal
1st Angle 2nd Angle 3rd Angle 4th Angle
OrthogonalProjection
3rd AngleProjection
1st AngleProjection
Emok26th ofJune2008
DihedralAngles 1st AngleEmphasised