Projection of planar surface
- 1. Presentation on Topic of PPT:- Projection Of Planar Surface Subject: Engineering Graphics
- 2. Ques.1 A rectangular plate of negligible thickness having 150mm length and 100mm width is resting on one of its smaller side on HP . The surface makes an inclination of 30° to HP and the smaller side makes an inclination of 60° to VP. Draw projections of the plane. Solution: 1.In the TV region,draw a rectangle of 150mm length and 100 mm width with 100 mm side perpendicular to the xy line . Name the corner as a,b,c and d. 2.Project all the four points on the xy line as the plate is assumed to lie on HP . Obtain a line view a’b’- c’d’ of the plate coinciding with xy line. 3.In the stage 2, copy the line view of the stage 1 and place it on the xy line. Rotate the line view with respect to side a’b’ through a given inclination of 30°. 4.Project all the four points from the FV of the stage 2 to the TV region of stage 2. project all the four points from the TV of stage 1 to the TV of stage 2. 5.Join the respective intersecting pointsof the projector lines to obtain the final projection points a,b,c and d. we get a reduced apparent shape of the rectangular plate. 6.Copy the reduced shape of the rectangular plate from TV region of the stage 2 and place it in the TV region of stage 3. 7.Rotate the copied view so that the smaller side ab makes 60° to VP. 8.Project all the four points from the TV region of stage 3 to the FV region of stage 3. project all the four points from the FV of stage2 to the FV of stage 3. 9.Join the respective intersecting points of the projectors lines to obtain the final projection points a’,b’,c’, and d’ . The shape of the rectangular plate appears to be as a parallelogram .
- 4. Ques 2. A pentagonal plate of negligible thickness and having edge length 100 mm is resting on one 0f its sides on VP . The plate is inclined 40° to VP nd the resting sides makes an inclination of 50° to HP. Draw projections of the plate. Solution: 1.In the FV region , draw a pentagon of 100 mm side ,with line joining one corner to the center o og the pentagon parallel to the xy line. Name the cornerr as a’,b’,c’,d’ and e’. 2.Project all the five points on the xy line as the plate in the stage 1 is lying on VP and obtain a line view a,b-c,e-d of the plate coinciding with the xy line. 3.In the stage 2, copy the line view of stage 1 and place it on the xy line . Rotate the line view about the corner point d through a given inclination of 40°. 4.Project all the four points from the TV of stage 2 to the FV of the stage2 . Project all the four points from the FV of stage 1 to the FV of stage 2. 5.Join the respective intersecting points of the projectors lines to obtain the the final projection points a’,b’,c’,d’ and e,.we get a reduced shape of the pentagon. 6.Copy the reduced shape of the pentagonal plate from FV region of stage 2 and place it in the FV region of stage 2. 7.Rotate the copied view about b’ so that the resting side a’b’ makes 50° to HP. 8.Project all the five points from the FV of the stage 3 to the TV of stage 3. project all the five points from the TV of stage 2 to the TV of stage 3 . 9.Join the respective intersecting points of the projector lines to obtain the final projection points a,b,c,d and e and obtain an irregular pentagonal shape.