1 NOTATIONS FOLLOWING NOTATIONS SHOULD BE FOLLOWED WHILE NAMEING DIFFERENT VIEWS IN ORTHOGRAPHIC PROJECTIONS. IT’S FRONT VIEW a’ a’ b’ OBJECT POINT A LINE AB IT’S TOP VIEW a a b IT’S SIDE VIEW a” a” b”

2 X Y 1 ST Quad. 2 nd Quad. 3 rd Quad. 4 th Quad. X Y VP HP Observer 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.

3 HP VP a’ a A POINT A IN 1 ST QUADRANT OBSERVER VP HP POINT A IN 2 ND QUADRANT OBSERVER a’ a A OBSERVER a a’ POINT A IN 3 RD QUADRANT HP VP A OBSERVER a a’ POINT A IN 4 TH QUADRANT HP VP A 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 90 0, In clockwise Direction (in 1 st 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. Convention: Horizontal plane is always rotated clockwise

4 PROJECTIONS OF A POINT IN THE 4 QUADRANTS HP VP POINT IN 2 nd QUADRANT VPHP PTPT PFPF VP POINT IN 3 rd QUADRANT HP VP POINT IN 4 th QUADRANT VP HP P T : TOP VIEW P F : FRONT VIEW PFPF PTPT PFPF HP VP POINT IN 1 st QUADRANT VP HP PTPT PFPF PTPT P P P P

5 How you will draw on the sheet POINT IN 2 nd QUADRANT PTPT PFPF POINT IN 3 rd QUADRANT POINT IN 4 th QUADRANT P T : TOP VIEW P F : FRONT VIEW PFPF PTPT PFPF POINT IN 1 st QUADRANT PTPT PFPF PTPT y y y y x x xx

6 A a a’ A a A a X Y X Y X Y For Fv For Tv For Fv For Tv For Fv POINT A ABOVE HP & INFRONT OF VP POINT A IN HP & INFRONT OF VP POINT A ABOVE HP & IN VP PROJECTIONS OF A POINT IN FIRST QUADRANT. ORTHOGRAPHIC PRESENTATIONS OF ALL ABOVE CASES. XY a a’ VP HP XY a’ VP HP a XY a VP HP 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 SIMPLE CASES OF THE LINE 1.A VERTICAL LINE ( PERPENDICULAR TO HP & // TO VP) 2.LINE PARALLEL TO BOTH HP & VP. 3.LINE INCLINED TO HP & PARALLEL TO VP. 4.LINE INCLINED TO VP & PARALLEL TO HP. 5.LINE INCLINED TO BOTH HP & VP. 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

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

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

11 X Y V.P. For Fv a’ b’ a b B A   For Tv F.V. T.V. X Y V.P. a’ b’ a b   F.V. T.V. For Fv For Tv B A X Y   H.P. V.P. a b FV TV a’ b’ A Line inclined to both Hp and Vp (Pictorial presentation) 5. 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) Orthographic Projections Fv is seen on Vp clearly. To see Tv clearly, HP is rotated 90 0 downwards, Hence it comes below xy. On removal of object i.e. Line AB Fv as a image on Vp. Tv as a image on Hp,  and  are NOT the true angles (inclinations) of the line with the planes

12 PROJECTIONS OF PLANES Information usually given: 1.Shape of the plane 2.Inclination of it’s surface with one of the reference planes 3.Inclination of one of it’s edges with the other reference plane will be given  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

13 HP a1a1 b1b1 c1c1 d1d1 VP a’ d’ c’ b’ VP a’ d’ c’b’ For Fv For Tv For F.V. For T.V. For F.V. HP a bc d a1’a1’ d1’d1’ c1’c1’ b1’b1’ a1a1 b1b1 c1c1 d1d1 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 ORTHOGRAPHIC TV-True Shape FV- Line // to xy ORTHOGRAPHIC FV- Inclined to XY TV- Reduced Shape ORTHOGRAPHIC FV- Apparent Shape TV-Previous Shape ABC

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. 14

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

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

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