NOTATIONS

1. 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 VIEWa’a’ b’ IT’S SIDE VIEW a” a” b”

2. 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. 2nd Quadrant VP 1ST Quad. 2nd Quad. F.V. 1st Quadrant Y Observer HP X Y X 3rdQuadrant Observer 4th Quad. 3rd Quad. 4th Quadrant

3. VP VP OBSERVER OBSERVER OBSERVER OBSERVER HP HP HP HP VP VP POINT A IN 1ST QUADRANT POINT A IN 2ND 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. a’ A A a’ a a a a a’ A a’ A POINT A IN 4TH QUADRANT POINT A IN 3RD QUADRANT Convention: Horizontal plane is always rotated clockwise

4. VP VP PF HP PT POINT IN 1st QUADRANT HP PROJECTIONS OF A POINT IN THE 4 QUADRANTS VP HP VP P P PF PT HP POINT IN 2nd QUADRANT PT: TOP VIEW PF: FRONT VIEW POINT IN 4th QUADRANT POINT IN 3rd QUADRANT PT HP HP HP VP HP VP PT PF P PF P VP VP

5. 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 PT: TOP VIEW PF: FRONT VIEW y PT PF PF POINT IN 4th QUADRANT POINT IN 3rd QUADRANT

6. For Tv For Tv For Tv POINT A IN HP & INFRONT OF VP POINT A ABOVE HP & IN VP POINT A ABOVE HP & INFRONT OF VP Y Y For Fv For Fv For Fv X X ORTHOGRAPHIC PRESENTATIONS OF ALL ABOVE CASES. a’ VP VP VP a’ a a’ X Y X Y a X Y a HP HP HP PROJECTIONS OF A POINT IN FIRST QUADRANT. A a’ a’ A Y a’ a a X A a Fv above xy, Tv below xy. Fv above xy, Tv on xy. Fv on xy, Tv below xy.

7. 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

8. 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.

9. Orthographic Pattern (Pictorial Presentation) V.P. Note: Fv is a vertical line Showing True Length & Tv is a point. a’ a’ V.P. b’ Fv A V.P. B b’ a’ Y A b’ X Y Y B Tv a b X X H.P. (Pictorial Presentation) V.P. Note: Fv & Tv both are // to xy & both show T. L. Fv a’ b’ b a X Y a b Tv H.P. For Tv 1. FV A Line perpendicular to Hp & // to Vp For Fv a b TV Orthographic Pattern For Tv 2. A Line // to Hp & // to Vp F.V. For Fv T.V.

10. V.P. Fv inclined to xy Tv parallel to xy. b’ F.V.  a’ X Y a b T.V. b’ V.P. a’ V.P. H.P. b’ B F.V.   B A Tv inclined to xy Fv parallel to xy. V.P. Y a’ Fv a’ b’ b A a b Ø T.V. X a X Y a Ø Tv b H.P. True Length 3. A Line inclined to Hp and parallel to Vp (Pictorial presentation) Orthographic Projections 4. F.V. A Line inclined to Vp and parallel to Hp (Pictorial presentation) Ø T.V. True Length

11. V.P. b’ FV a’  On removal of object i.e. Line AB Fv as a image on Vp. Tv as a image on Hp, For Tv For Tv X Y b’ b’ V.P. V.P. a  B B F.V. F.V. TV   Y Y H.P. a’ a’ b For Fv For Fv A A   X X a a b b T.V. T.V. 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) 5. A Line inclined to both Hp and Vp (Pictorial presentation) NOTE: aand b are NOT the true angles (inclinations) of the line with the planes

12. 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’sedgeswith the otherreference plane will be given

13. CASE OF A RECTANGLE – OBSERVE AND NOTE ALL STEPS. For Tv For T.V. For T.V. For Fv For F.V. For F.V. VP VP VP c1’ d1’ d’ a1’ d’ a’ B A C b1’ a’ c’ b’ c’ b’ d1 d1 a1 a d a1 b c b1 b1 c1 c1 HP HP HP ONE SMALL SIDE INCLINED TO VP PICTORIAL PRESENTATION SURFACE INCLINEDTO HP PICTORIAL PRESENTATION SURFACE PARALLELTO HP PICTORIAL PRESENTATION FV-1 FV-2 FV-3 T V-1 T V-2 T V-3 ORTHOGRAPHIC FV- Apparent Shape TV-Previous Shape ORTHOGRAPHIC TV-True Shape FV- Line // to xy ORTHOGRAPHIC FV- Inclined to XY TV- Reduced Shape

14. 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.

15. x y FOR T.V. S.V. F.V. ORTHOGRAPHIC PROJECTIONS FRONT VIEW L.H.SIDE VIEW FOR F.V. FOR S.V. PICTORIAL PRESENTATION IS GIVEN DRAW THREE VIEWS OF THIS OBJECT BY FIRST ANGLE PROJECTION METHOD TOP VIEW

16. 3rd. Angle projection Top view Front view Right Side view

17. X Y FOR T.V. S.V. F.V. ORTHOGRAPHIC PROJECTIONS L.H.SIDE VIEW FRONT VIEW FOR F.V. FOR S.V. TOP VIEW PICTORIAL PRESENTATION IS GIVEN DRAW THREE VIEWS OF THIS OBJECT BY FIRST ANGLE PROJECTION METHOD