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Published byVivien Brooks Modified over 7 years ago
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NOTATIONS FOLLOWING NOTATIONS SHOULD BE FOLLOWED WHILE NAMEING DIFFERENT VIEWS IN ORTHOGRAPHIC PROJECTIONS. OBJECT POINT A LINE AB IT’S TOP VIEW a a b IT’S FRONT VIEW a’ a’ b’ IT’S SIDE VIEW a” a” b”
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IF OBSERVED ALONG X-Y LINE ( IN RED ARROW DIRECTION)
2nd Quadrant VP 2nd Quad. 1ST Quad. F.V. 1st Quadrant Y Observer X Y HP X 3rdQuadrant Observer 3rd Quad. 4th Quad. 4th Quadrant THIS QUADRANT PATTERN, IF OBSERVED ALONG X-Y LINE ( IN RED ARROW DIRECTION) WILL EXACTLY APPEAR AS SHOWN ON RIGHT SIDE AND HENCE, IT IS FURTHER USED TO UNDERSTAND ILLUSTRATION PROPERLLY.
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Convention: Horizontal plane is always rotated clockwise
POINT A IN 2ND QUADRANT POINT A IN 1ST QUADRANT Point A is Placed In different quadrants and it’s Fv & Tv are brought in same plane for Observer to see clearly. Fv is visible as it is a view on VP. But as Tv is a view on Hp, it is rotated downward 900, In clockwise Direction (in 1st quadrant).The In front part of Hp comes below xy line. The HP behind the Vp is also rotated clockwise, and therefore comes above the xy line. Observe and note the process. HP VP VP HP a’ A A a’ a OBSERVER OBSERVER a a HP VP HP VP OBSERVER OBSERVER a a’ A a’ POINT A IN 3RD QUADRANT A POINT A IN 4TH QUADRANT Convention: Horizontal plane is always rotated clockwise
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PROJECTIONS OF A POINT IN THE 4 QUADRANTS
HP VP POINT IN 1st QUADRANT PT PF VP HP VP P P PF PT HP POINT IN 2nd QUADRANT PT: TOP VIEW PF: FRONT VIEW POINT IN 3rd QUADRANT POINT IN 4th QUADRANT PT HP HP HP VP HP VP PT PF P PF P VP VP
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How you will draw on the sheet
PF PF PT x y x y PT POINT IN 2nd QUADRANT POINT IN 1st QUADRANT PT x y x y PT: TOP VIEW PF: FRONT VIEW PT PF PF POINT IN 3rd QUADRANT POINT IN 4th QUADRANT
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PROJECTIONS OF A POINT IN FIRST QUADRANT.
POINT A ABOVE HP & INFRONT OF VP POINT A ABOVE HP & IN VP POINT A IN HP & INFRONT OF VP For Tv For Tv For Tv A a’ a’ A For Fv X Y X Y Y For Fv a’ a a X a A For Fv ORTHOGRAPHIC PRESENTATIONS OF ALL ABOVE CASES. Fv above xy, Tv below xy. Fv above xy, Tv on xy. Fv on xy, Tv below xy. X Y a a’ VP HP X Y a’ VP HP a X Y a VP HP a’
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Projection of lines, planes, solids
Line – consists of 2 points Plane – consists of 3 or more points Solid – consists of more than 3 points Therefore in order to project lines, planes and solids, we need to project their corresponding points and join them
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PROJECTIONS OF STRAIGHT LINES.
AIM:- TO DRAW IT’S PROJECTIONS - FV & TV. INFORMATION REGARDING A LINE: IT’S LENGTH, POSITION OF IT’S ENDS WITH HP & VP IT’S INCLINATIONS WITH HP & VP SIMPLE CASES OF THE LINE A VERTICAL LINE ( LINE PERPENDICULAR TO HP & // TO VP) LINE PARALLEL TO BOTH HP & VP. LINE INCLINED TO HP & PARALLEL TO VP. LINE INCLINED TO VP & PARALLEL TO HP. LINE INCLINED TO BOTH HP & VP.
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V.P. A Line perpendicular to Hp & // to Vp V.P. A Line // to Hp &
Orthographic Pattern For Tv (Pictorial Presentation) V.P. X Y H.P. V.P. a’ b’ a b Fv Tv Note: Fv is a vertical line Showing True Length & Tv is a point. a’ b’ B A 1. FV A Line perpendicular to Hp & // to Vp X Y For Fv a b TV Orthographic Pattern (Pictorial Presentation) X Y V.P. X Y H.P. V.P. a b a’ b’ Fv Tv Note: Fv & Tv both are // to xy & both show T. L. For Tv 2. b’ a’ A Line // to Hp & // to Vp F.V. A B For Fv b a T.V.
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True Length V.P. A Line inclined to Hp and parallel to Vp V.P.
X Y V.P. X Y H.P. V.P. F.V. T.V. a b a’ b’ Fv inclined to xy Tv parallel to xy. True Length 3. b’ a’ F.V. A Line inclined to Hp and parallel to Vp (Pictorial presentation) A B b a T.V. Orthographic Projections V.P. Tv inclined to xy Fv parallel to xy. X Y H.P. V.P. Ø a b a’ b’ Tv Fv 4. A Line inclined to Vp and parallel to Hp (Pictorial presentation) a’ b’ F.V. Ø B A Ø a b T.V. True Length
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(Pictorial presentation)
For Fv For Tv B A For Tv X Y V.P. a’ b’ a b F.V. T.V. V.P. 5. A Line inclined to both Hp and Vp (Pictorial presentation) a’ b’ F.V. B A X Y On removal of object i.e. Line AB Fv as a image on Vp. Tv as a image on Hp, For Fv a b T.V. X Y H.P. V.P. a b FV TV a’ b’ NOTE: a and b are NOT the true angles (inclinations) of the line with the planes Orthographic Projections Fv is seen on Vp clearly. To see Tv clearly, HP is rotated 900 downwards, Hence it comes below xy. Note These Facts:- Both Fv & Tv are inclined to xy. (No view is parallel to xy) Both Fv & Tv are reduced lengths. (No view shows True Length)
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PROJECTIONS OF PLANES A plane is a two-dimensional geometrical entity
It has length and width but no thickness For practical purposes, a flat face of an object may be treated as a plane A plane which has limited extent (has fixed shape) is termed as a lamina Information usually given: Shape of the plane Inclination of it’s surface with one of the reference planes Inclination of one of it’s edges with the other reference plane will be given
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C A B CASE OF A RECTANGLE – OBSERVE AND NOTE ALL STEPS.
SURFACE PARALLEL TO HP PICTORIAL PRESENTATION SURFACE INCLINED TO HP PICTORIAL PRESENTATION ONE SMALL SIDE INCLINED TO VP PICTORIAL PRESENTATION For T.V. For T.V. For Tv FV-1 FV-2 FV-3 For Fv For F.V. For F.V. T V-1 T V-2 T V-3 ORTHOGRAPHIC TV-True Shape FV- Line // to xy ORTHOGRAPHIC FV- Inclined to XY TV- Reduced Shape ORTHOGRAPHIC FV- Apparent Shape TV-Previous Shape VP VP a’ d’ c’ b’ VP a’ d’ c’ b’ HP a1 b1 c1 d1 a1’ d1’ c1’ b1’ HP a b c d HP a1 b1 c1 d1 C A B
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Center lines Drawn to indicate the axis of cylindrical, conical or spherical objects or details. Thin long chains composed of alternately long and short dashes. Longer dashes are approximately 6 to 8 times the short dashes in length. Center of a circular curve is indicated by a cross made up of centerline chains.
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DRAW THREE VIEWS OF THIS OBJECT BY FIRST ANGLE PROJECTION METHOD
FOR T.V. S.V. F.V. ORTHOGRAPHIC PROJECTIONS FRONT VIEW L.H.SIDE VIEW FOR F.V. FOR S.V. x y PICTORIAL PRESENTATION IS GIVEN DRAW THREE VIEWS OF THIS OBJECT BY FIRST ANGLE PROJECTION METHOD TOP VIEW
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3rd. Angle projection Top view Front view Right Side view
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DRAW THREE VIEWS OF THIS OBJECT BY FIRST ANGLE PROJECTION METHOD
FOR T.V. S.V. F.V. ORTHOGRAPHIC PROJECTIONS FRONT VIEW L.H.SIDE VIEW FOR F.V. X Y FOR S.V. TOP VIEW PICTORIAL PRESENTATION IS GIVEN DRAW THREE VIEWS OF THIS OBJECT BY FIRST ANGLE PROJECTION METHOD
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