1 / 13

ANNOUNCEMENTS

ANNOUNCEMENTS. Friday, april 22 nd Will be used as the buffer day for mel 110 PRACTICALS. - TIME: 9 AM TO 1 PM. - VENUE: WS 204 LAB 13. WILL BE COMPUTER BASED IN THE CAGIL.

akiko
Télécharger la présentation

ANNOUNCEMENTS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ANNOUNCEMENTS Friday, april 22ndWill be used as the buffer day for mel 110 PRACTICALS. -TIME: 9 AM TO 1 PM. -VENUE: WS 204LAB 13. WILL BE COMPUTER BASED IN THE CAGIL.

  2. A flag post is held by 3 wires symmetrically placed around it. They are hooked to the post at a height of 12.5 m. and anchored to the ground at a distance of 2m, 2.5m, and 3 m from the pole axis respectively. Draw their projections and find their true lengths and true inclinations with the horizontal by method of rotation. • Draw top and front views incorporating given distances. • Use method of revolution/rotation to obtain true lengths of the wires. • With o as center and oa, ob, oc as radii, rotate the wires so that they are parallel to frontal plane. • a, b, and gare the true inclinations with the horizontal. a Wire 2.5 c 3 o 2 TV b FV o a b g 12.5 Ground a’ b’ c’ Flag post

  3. An oblique square pyramid of side 4 cm and height 5 cm is placed with its base a, b, c, d horizontal with ab making an angle of 30o to the vertical plane. Draw its projections and find the true lengths and true inclinations with the horizontal plane of its edges ao, bo, co, do meeting at the vertex o. The axis of the pyramid is inclined at 60o to the horizontal and parallel to the frontal plane. • Draw top view of square with one side having angle 30o with the frontal plane. • Find the point of intersection of diagonals of the square. This is the lower point of the pyramid axis. • Project this point in the front view and draw the axis from it, at an angle of 60o to the horizontal up to a vertical height of 5cm. • As the axis is parallel to the frontal plane, it can be projected back into the top view. • Find true lengths by rotation method. In this case o has been taken as center and oa, ob, oc, od as radii, rotate the lines in top view to make them parallel to frontal plane. • Project true lengths. d 4 c o f a T 30o b o’ F a b 5 g d 60o b’ c’ f’ d’ a’ a1 d1 b1 c1 True lengths

  4. Three points A, B, and C represent milestones and are 7.5 mabove the ground level, on the ground level, and 9 m below ground level and 9 m below ground level respectively. They are connected with each other by roads and are seen at angles of depression of 10o, 15o and 30o respectively from a point O on a hill 30 m above the ground level. A is due Northeast, B is due North and C is due Southeastof O. Find the lengths of the connecting roads. SE NE Obtain true lengths in one view by subtending given angles from pt. O to the respective heights Required distance is True Length of AB + BC + CA HINT: Rotate AB, BC, CA in any one view and obtain True Lengths in the other view. E.g. AC1 is one such length Add the distances to get the final answer C C1 N A T O B F O 10o 30o 15o 30 A’ 7.5 Ground level B’ 9 C’

  5. To find the piercing point and angle of inclination of a line with a plane Draw auxiliary views such that you get the TRUE LENGTH of the line and EDGE VIEW of the plane Edge view of the plane A1 A2 A1 T True length of principal line p1 p2 Edge view of plane p Line A2 T F A3 p3 Plane p’ True length of line Part of the line hidden by the plane should be shown dotted Angle between line and plane Principal line p, p’, p1, p2, p3 are the piercing point of the line with the plane

  6. To find the line of intersection of two planes W X Q R B A P S AB is the line of intersection obtained by getting the piercing point (A) of WZ with plane PQRS and (B) of XY with plane PQRS. Z Y

  7. To find the line of intersection of two planes X W Q R B A P S AB is the line of intersection. In this case the piercing point of XY with PQRS (B) andof PS with plane WXYZ (A) is to be obtained. Z Y

  8. To find corresponding points on lines appearing vertical in TV and FV and obtaining True Length The ratio of corresponding distances in both views should be same True length b 3. Join b1 and b. Draw a line parallel to b1b to intersect ab in d d c a a e b1 d1 a 2. Project d’ and b’ upto a line that is horizontal and in line with a meeting it at d1 and b1 respectively T F d’ a’ b’ d’ e’ c’ 1. With a’ as center rotate a’d’ and a’b’ and make the line horizontal Principle line b’

  9. To find the TRACE of a line: Case I Horizontal Trace: Projection of point of intersection of extension of AB with the Top plane Definition: The point of intersection of a line-produced with a plane is called its TRACE on that plane. HT b HT a B H T V H V F b’ a’ A VT VT Vertical Trace: Projection of point of intersection of extension of AB with the Frontal plane

  10. To find the TRACE of a line: Case II Definition: The point of intersection of a line-produced with a plane is called its TRACE on that plane. Horizontal Trace: Projection of point of intersection of extension of AB with the Top plane b VT a HT HT A VT T H F V H V B a’ b’ Vertical Trace: Projection of point of intersection of extension of AB with the Frontal plane

  11. To find the TRACE of a line: Case III Horizontal Trace: Projection of point of intersection of extension of AB with the Top plane Definition: The point of intersection of a line-produced with a plane is called its TRACE on that plane. HT a TL HT A b H T F a’ B TL VT b’ Vertical Trace: Projection of point of intersection of extension of AB with the Frontal plane VT

  12. To find the TRACE of a line (Trapezoidal method): Case III Horizontal Trace: Projection of point of intersection of extension of AB with the Top plane Definition: The point of intersection of a line-produced with a plane is called its TRACE on that plane. HT a TL HT A a A b B T b F a’ B TL b’ Vertical Trace: Projection of point of intersection of extension of AB with the Frontal plane VT

  13. Q. Two regular pentagonal plates ABCDE and AFGHI of equal sizes (side length 30 mm) are joined at A such that the included angle between them is 75o. The edges opposite to corner A are on the ground and make 30o with a vertical wall. Draw projections of the plates. Find the angle of the plates with the wall. Approach II: Include a wall at 30o to the edges DC and GH E F D G A Obtain edge view using principal plane concept in SAV. Angle that it makes with the axis is the angle with the wall Approach I: Use Frontal plane as the wall C H B I E F E F D G D G A PAV, in which PAP is the wall A Principal line 30o C H C H B I 30o B I A’ A’ B’,E’ I’,F’ I’,F’ 75o B’,E’ C’,D’ H’,G’ C’,D’ H’,G’ Auxiliary view will give edge view and angle with frontal plane

More Related