TECHNICAL DRAWING Designing things on paper TYPES OF DRAWINGS All - PowerPoint PPT Presentation

TECHNICAL DRAWING Designing things on paper

TYPES OF DRAWINGS All Drawings Technical Artistic Drawings Diagrams Sketches (technical/engineering ) ( design & technical) (conceptual) simulated perspective Diagram Diagram Oblique Isometric Multi view (design plan) (technical) projection projection orthographic Less technical More technical

CONCEPTUAL SKETCHES  When hen you f ou fir irst st get get an an idea f idea for or something somet hing you ou want ant to to build build you ou may may dr draw aw it it rough oughly, , without without using using instr instrument uments s or or accu accurate te sca scales. les. This his is is called called a a conc concept eptual ual sk sketc etch.

 A conceptual sketch…  Al Allows s an i an idea dea to to be be exp xpresse essed d qu quickl kly y in n graphic phic for orm  Is pr Is prepa epared ed fr free ee-hand hand (w (withou thout d t drawi awing ng instr nstrume uments) nts)  Is not done Is not done to s to scale, cale, but i but it t respec espects ts the the rules of ules of te technical hnical dr drawi awing ng a as s muc much h as as possi possible, ble, a and i nd is made s made roug oughl hly y pr propo oporti tiona onal to to the object the object repr epresente esented. d.

CONCEPTUAL SKETCHES  On On a sep separ arate te she sheet et of of pa paper per dr draw aw a conceptual conceptual sk sketc etch h a a de devi vice ce used used to to cut cut a piec a piece e of of pa pape per: :

CONCEPTUAL SKETCHES  On On a sep separ arate te she sheet et of of pa paper per dr draw aw a conceptual conceptual sk sketc etch h a a de devi vice ce used used to to cut cut a piec a piece e of of pa pape per: :

TECHNICAL DRAWINGS  Ser Serve e as as a a ref efer erence to ence to wor orker ers, s, ar architects hitects or or mac machinists. hinists.  When hen you ou ar are r e read eady y to to des design ign the the details, details, you ou mak make e a a tec technical hnical dr drawing, awing, done don e with with mor more e detail detail and and mor more e acc accur urac acy.

CONCEPTUAL SKETCHES  On On a sep separ arate te she sheet et of of pa paper per dr draw aw a conceptual conceptual sk sketc etch h a a de devi vice ce used used to to cut cut a piec a piece e of of pa pape per: :

CONCEPTUAL SKETCHES  On On a sep separ arate te she sheet et of of pa paper per dr draw aw a conceptual conceptual sk sketc etch h a a de devi vice ce used used to to cut cut a piec a piece e of of pa pape per: :

DIFFERENCE:  Sk Sketc etch: h: Made without drafting tools... Just pencil and paper. Scale is approximate, not accurate, but the sketch should still look like the object.  Dr Drawing awing: Made with drafting tools... Ruler, set squares, protractor and compass. Scale should be accurate and the drawing carefully made.

A TECHNICAL DRAWING Presents all the information necessary for the object’s • construction. Is made with great precision, • Requires the use of rulers, compass and protractor or • drafting software. Is done to scale, and respects the proportions of the • object represented. Respects conventions in the mode of the representation. •

TECHNICAL DRAWING OF FIGHTER PLANE (ISOMETRIC PROJECTION, EXPLODED VIEW)

TECHNICAL DRAWINGS CAN REPRESENT THINGS… TECHNICAL DRAWING OF A “SIMPLE” SPOON MU MULTI TI-VIEW VIEW, , OR ORTHOGRAPHIC THOGRAPHIC PR PROJECTI OJECTION ON

TECHNICAL DRAWINGS CAN REPRESENT THINGS… TECHNICAL DRAWINGS OF A “COMPLEX” SPACECRAFT Photograph of Mercury Spacecraft Technical Drawing of Mercury Spacecraft, Top View, Orthographic  Technical Drawing of Mercury Spacecraft, Isometric Projection

BAS ASIC IC TE TECHNICA CHNICAL L DR DRAWING WING LINES LINES Draw the visible Visible Represents the Thick object edges (Object) Line outline with these lines Draw hidden Hidden Line Shows hidden Medium edges with details dashed these Construction Used during Fine Faint lines, sometimes Line drafting coloured Dimension & Dimension Used to indicate Fine, 8cm extension lines Line a dimension with arrows go together! Extension Used with a Fine 8 cm Line dimension line Near arrows Center Shows center or Fine (Axial) Line symmetry With dash in middle

BAS ASIC IC TE TECHNICA CHNICAL L DR DRAWING WING LINES LINES Sometimes in Ghost Line Shows possible Fine other color movement dashed Used only if you Cutting Position of a Thick plan to draw a plane line cross-section With arrows cross section Show where it Hatched Surface of a Fine is solid (section cross-section Lines view only!!) Used only for Long Break Shows that a Fine large objects line is shortened With zig-zag Short break Object shortened Medium or cut away With curve (cutaway) Attaches a comment Leader Line Points to Fine or angle or dimension something With bent to an object. arrow

BASIC ASIC DRA DRAFTING FTING TOO OOLS LS

Projection Used for Orthographic Drafting, maps, floor plans (top view) Technical drawings, drafting, Orthographic conceptual sketches (sometimes) (multi-view) Artistic drawing, conceptual True Perspective sketches (one, two or three point) Conceptual sketches, technical Isometric COMPARISON OF PROJECTIONS drawings (sometimes) (simulated perspective) Oblique Conceptual sketches (simulated perspective)

PROJECTIONS  Per erspectiv spective e pr projections ojections  Multi Multi-view view pr projections ojections  Isometri Isometric c pr projection ojection  Oblique Oblique pr projection ojection

Vanishing Point TR TRUE UE PERSPECTIVE PERSPECTIVE  Objec Objects ts dr drawn awn in in tr true ue per perspect spectiv ive e look look r realist ealistic. ic.  They have “vanishing points” where straight lines seem seem to to con conver erge ge  The hey y ca can n ha have e on one, e, tw two o or or thr three ee va vanish nishing ing po points, ints, Vanishing Points depe de pend nding ing on on ho how w muc much h the the ar artist tist wan ants ts to to wor ork. k.  Bu But t in in tr true ue per perspect spectiv ive, e, objects far objects ar aw away wil ay will l be be dr drawn smaller awn smaller than nea than nearby rby objects… not a good idea in awing ! technic tec hnical al dr drawing Vanishing Points

MORE MORE TR TRUE UE PERSP PERSPECTIVE ECTIVE DRA DRAWINGS WINGS

ISOME ISOMETR TRIC IC PR PROJ OJEC ECTION TION (A SIMULA (A SIMULATE TED D PE PERSPE RSPECTIV CTIVE E DR DRAWIN WING G ST STYLE) YLE)  Iso Isome metric tric (or (or simula simulated ted p per erspe spectiv ctive) e) dr drawing awings l s loo ook a k at f t fir irst st li like pe e perspe spectiv ctive e drawings…  But the lines don’t co conver erge ge. . T The here e ar are e no no van vanishing ishing po points ints an and d distan distant o t objec bjects ts ar are th e the sa e same me siz size a e as s 60 ˚ ne nearb arby on y ones. es. R epresents 90˚  Ri Righ ght a t ang ngles i les in n isome isometri tric c pr projec ojections tions ar are u e usu suall ally y rep eprese esente nted d by 6 by 60 ° or or Represents 90° 120 120 ° an angles. les.

MO MORE RE ISOMETRIC ISOMETRIC DRA DRAWING WINGS

OBLIQUE OBLIQUE PR PROJECTION OJECTION ANOTHER “SIMULATED” PERSPECTIVE  Similar to isometric projection, it is also a “simulated perspective” This side is not!  In oblique projections, the side This side is of the object facing you is accurate drawn “square” and accurate 90° 90° =60° (that is with right angles at 90 ° and its measurements proportional)  The sides not facing you are distorted

OR ORTHOGRAPHIC THOGRAPHIC PR PROJECT OJECTIONS IONS  Orthographic projections “flatten” one vi view of ew of t the object he object onto a onto a shee sheet t of of pa paper per, , whil hile r e retaining the c etaining the cor orrec ect t pr prop opor orti tion ons s (ang (angles les and dim and dimensions) ensions)  Ma Maps ar ps are an e an example xample of of or orthog thographic phic pr projection (a ojection (a top view) top view)  The he tr trouble w ouble wit ith h or orthog thographic phic projections is that one view usually isn’t enough. enough.  Ma Maps and floor ps and floor-plans plans ar are e exceptions ceptions, , wher here one e one top top-view view is is often enough. often enough.

ORTHOGRAPHIC PROJECTION (MULTI-VIEW)  Draws an object as it would be seen from several different directions  The views are “flat”, with all angles shown correctly and all measurements to scale.