SOLIDS To understand and remember various solids in this subject properly, those are classified & arranged in to two major groups. Group A Group B Solids having top and base of same shape Solids having base of some shape and just a point as a top, called apex. Cylinder Cone Prisms PyramidsTriangular Square Pentagonal Hexagonal Triangular Square Pentagonal Hexagonal Cube Tetrahedron ( A solid having ( A solid having six square faces) Four triangular faces)
SOLIDS Dimensional parameters of different solids. Square Prism Square Pyramid Cylinder Cone Apex Apex TopRectangular Slant Face Edge Triangular Longer Base Face Base Base Base EdgeCorner of Edge Edge Corner of Generators base of of base Imaginary lines Base Base generating curved surface of cylinder & cone. Sections of solids( top & base not parallel) Frustum of cone & pyramids. ( top & base parallel to each other)
STEPS TO SOLVE PROBLEMS IN SOLIDS ( IF IT IS INCLINED TO HP, ASSUME IT STANDING ON HP) ( IF IT IS INCLINED TO VP, ASSUME IT STANDING ON VP) IF STANDING ON HP - IT’S TV WILL BE TRUE SHAPE OF IT’S BASE OR TOP: IF STANDING ON VP - IT’S FV WILL BE TRUE SHAPE OF IT’S BASE OR TOP. IT’S OTHER VIEW WILL BE A RECTANGLE ( IF SOLID IS CYLINDER OR ONE OF THE PRISMS): IT’S OTHER VIEW WILL BE A TRIANGLE ( IF SOLID IS CONE OR ONE OF THE PYRAMIDS): DRAW FV & TV OF THAT SOLID IN STANDING POSITION: STEP 2: CONSIDERING SOLID’S INCLINATION ( AXIS POSITION ) DRAW IT’S FV & TV. STEP 3: IN LAST STEP, CONSIDERING REMAINING INCLINATION, DRAW IT’S FINAL FV & TV. GENERAL PATTERN ( THREE STEPS ) OF SOLUTION: GROUP A SOLID. GROUP A SOLID. GROUP B SOLID. GROUP B SOLID. CYLINDER CYLINDER CONE CONE AXIS AXIS AXIS AXIS INCLINED HP AXIS AXIS VERTICAL INCLINED HP INCLINED HP VERTICAL INCLINED HP AXIS AXIS er AXIS AXIS er AXIS TO VP INCLINED INCLINED VP AXIS TO VP INCLINED INCLINED VP VP VP Three steps Three steps Three steps Three stepsIf solid is inclined to Hp If solid is inclined to Hp If solid is inclined to Vp If solid is inclined to Vp
STANDING ON H.P RESTING ON H.P LYING ON H.P On it’s base. On one point of base circle. On one generator. (Axis perpendicular to Hp (Axis inclined to Hp (Axis inclined to Hp And // to Vp.) And // to Vp) And // to Vp) F.V. F.V. F.V.X Y While observing Fv, x-y line represents Horizontal Plane. (Hp)X While observing Tv, x-y line represents Vertical Plane. (Vp) Y T.V. T.V. T.V. STANDING ON V.P RESTING ON V.P LYING ON V.P On it’s base. On one point of base circle. On one generator. Axis perpendicular to Vp Axis inclined to Vp Axis inclined to Vp And // to Hp And // to Hp And // to Hp
CATEGORIES OF ILLUSTRATED PROBLEMS!PROBLEM NO.1, 2, 3, 4 GENERAL CASES OF SOLIDS INCLINED TO HP & VPPROBLEM NO. 5 & 6 CASES OF CUBE & TETRAHEDRONPROBLEM NO. 7 CASE OF FREELY SUSPENDED SOLID WITH SIDE VIEW.PROBLEM NO. 8 CASE OF CUBE ( WITH SIDE VIEW)PROBLEM NO. 9 CASE OF TRUE LENGTH INCLINATION WITH HP & VP.PROBLEM NO. 10 & 11 CASES OF COMPOSITE SOLIDS. (AUXILIARY PLANE)PROBLEM NO. 12 CASE OF A FRUSTUM (AUXILIARY PLANE)
Axis of the solid inclined to………at………Edge or side of the base inclined to …….at………Assumptions for initial position1. Keep the axis perpendicular to the principal plane from which it is to be inclined.2. Keep the edge perpendicular to the principal plane from which it is to be inclined.Steps for solution1. Incline the axis.2. Incline the edge.
Problems on Projection of SolidsTo be discussed in the class 13.10,13.13,13.20,13.23,13.31To draw on the sheet 13.19,13.21,13.22,13.23,13.31,11
Q13.10 Draw the projections of a pentagonal prism , base 25 mm side and axis 50 mm long,resting on one of its rectangular faces on the H.P. with the axis inclined at 45º to the V.P.As the axis is to be inclined with the VP, in the first view it must be kept perpendicular to theVP i.e. true shape of the base will be drawn in the FV with one side on XY line (b’) 2’ b1’ 21’ (a’) (c’) a1’ 31 ’ c1’ 11’ 1’ 3’ X (d’) e1’ d1 ’ 41’ Y (e’) 45º 51’ 25 45º c 5’ 4’ d a (e) b (d) c b e a 3 50 4 2 5 1 1 (5) 2 (4) 3
Problem 13.12: A hexagonal pyramid base 25 mm side and axis 50 mm long has an edge ofits base on ground. Its axis is inclined at 30 to the ground and parallel to the V.P. Draw itsprojectionsLet us solve this question first by rotation method. As the axis is to be inclined with the HP, in the first position we have to keep it perpendicular to HP, and as one side of base is resting on the ground (HP), we have to keep one edge of the hexagon perpendicular to VP Now let us solve this question X1 o’by auxiliary plane method. o’ a’b’ c’ f’ 60º o1 X (a’) c’ (e’) 30º e’d’ Y b’ (f’) d’ 30º a1 Y1 f1 f f1 b1 e a1 e1 e1 a c1 o1 d1 o 30 b1 b d d1 c c1
Problem 13.13: Draw the projections of a cone, base 75 mm diameter and axis 100 mmlong, lying on the HP on one of its generator with the axis parallel to the VP. o’ 10’ 11’ 9’ 12’ 8’ 1’ 7’ 2’ 6’ 3’ 5’X Y 10’ 11’ 12’ 1’ 2’ 3’ 4’ 4’ 9’ 8’ 7’ 6’ 5’ 1 12 2 11 3 10 o 4 9 5 8 6 7
Problem 13.20:A pentagonal pyramid base 25 mm side and axis 50 mm long has one of itstriangular faces in the VP and the edge of the base contained by that face makes an angle of 30ºwith the HP. Draw its projections.Step 1. Here the inclination of the axis is given indirectly. As one triangular face of the pyramid is in the VP its axis will beinclined with the VP. So for drawing the first view keep the axis perpendicular to the VP. So the true shape of the base willbe seen in the FV. Secondly when drawing true shape of the base in the FV, one edge of the base (which is to be inclinedwith the HP) must be kept perpendicular to the HP.Step 2. In the TV side aeo represents a triangular face. So for drawing the TV in the second stage, keep that face on XY sothat the triangular face will lie on the VP and reproduce the TV. Then draw the new FV with help of TVStep 3. Now the edge of the base a1’e1’ which is perpendicular to the HP must be in clined at 30º to the HP. That is inclinethe FV till a1’e1’ is inclined at 30º with the HP. Then draw the TV. o 1’ b 1’ b’ a’ a1’ o 1’ c1’ b 1’ o’ c’ c1’ 25 e’ e1’ a1’ d’ d 1’ d 1’ e1’ a b 30º e o1 e1 a1 d c X o ae Y bd d1 b1 50 c c1 o
Q13.22: A hexagonal pyramid base 25 mm side and axis 55 mm long has one of its slant edge on the ground. A planecontaining that edge and the axis is perpendicular to the H.P. and inclined at 45º to the V.P. Draw its projectionswhen the apex is nearer to the V.P. than the base.The inclination of the axis is given indirectlyon the HP and the axis is seen in edge of aspyramid rests on the HP its FV is The vertical plane containing the slant edge in this problem. When the slant the TV a o1d1 for drawing auxiliary axisinclined with the HP so while deciding first1o1 extended. Then draw projectorskept perpendicular to 1 to i.e. true shape ofto draw an auxiliary plane X1Y1 at 45º from d view the axis of the solid must be from each point i.e. aHP f1 perpendicular thebase 1 andbe seen in points measuring their distances in the FV in the old XY have to keep the corners at the extreme ends. X1Y will mark the the TV. Secondly when drawing hexagon from TV we line. o’ f1’ a’ a1’ e1’ b’ X1 f’ b1’ c1’ c’ d1’ e’ b’ c’ d’ o’ X a’ f’ e’ d’ Y f1 o1 ’ e1 f e a d d1 a1 o 45º Y1 o1 b c c1 b1
Problem 13.21: A square pyramid Solution Steps:base 38mm sides & axis 50 mm long, In all suspended cases axis shows inclination with Hp.is freely suspended from one of the 1.Hence assuming it standing on Hp, draw Tv - a square with edges equallycorners of its base. Draw its projections inclined with the VP.when the axis as a vertical plane makes 2.Project Fv & locate CG position on axis – ( ¼ H from base.) and name g’ andan angle of 45º with the VP. Join it with corner a’ 3.As 2nd Fv, redraw first keeping line g’a’ vertical. 4.In 3rd stage draw TV with c1a1o1 making 45º with VP and draw corresponding FV a1’ a’ o’ b’d’ d 1’ b 1’ g’ 50 c’ o’ g’ o 1’ c1’ 12.5 45ºX a’ b’d’ c’ Y b1 b1 b c1 c1 a1 c a1 a o1 o d1 o1 38 d d1
Solution Steps:Problem 13.23: A cube of 25 mm 1.Assuming standing on HP, begin with TV,a square with all sideslong edges is so placed on HP on one equally inclined to XY. Project FV and name all points of FV & TV. 2.Draw a body-diagonal joining c’ with 1’( This can become // to xy)corner that a body diagonal is 3.From 3’ drop a perpendicular on this and name it p’ parallel to HP and perpendicular to 4.Draw 2nd Fv in which 3’p’ line is vertical means c’-1’ diagonalVP Draw it’s projections. must be horizontal. .Now as usual project TV.. 6.In final TV draw same diagonal is perpendicular to VP as said in problem. Then as usual project final FV. a1 ’ a’ b’d ’ b1’ d1’ a’ b’ d’ c’ p’ c1 ’ c’ p’ 1’ 11’ 21’ 41’ 2’ 4’ X 1’ 2’ 4’ 3’ 3’ 31’1 1 Y d4 41 d1 21 41 a1 c3 11 a1 31 c1 b1 d1 21 b1 c1 b2
Problem 13.31: A regular pentagonal pyramid with the sides of its base 30 mm and height 80 mmrests on an edge of the base. The base is tilted until its apex is 50 mm above the level of the edgeof the base on which it rests. Draw the projections of the pyramid when the edge on which itrests, parallel to the VP and the apex of the pyramid points towards the VP. o’ o’ o1 a’ 80 a1 b’e’ 50 e1 b1X a’ b’ c’ c’ d1 o1 c1 Y e’ d’ d’ e e1 d 108º d1 o a1 o1 a 30 108º c1 c d1 c1 b b1 e1 b1 a1
Problem 5:A tetrahedron of 50 mm Solution Stepslong edges is resting on one edge on As it is resting assume it standing on Hp.Hp while one triangular face containing Begin with Tv , an equilateral triangle as side case as shown:this edge is vertical and 450 inclined to First project base points of Fv on xy, name those & axis line.Vp. Draw projections. From a’ with TL of edge, 50 mm, cut on axis line & mark o’ (as axis is not known, o’ is finalized by slant edge length)IMPORTANT: Then complete Fv.Tetrahedron is a In 2nd Fv make face o’b’c’ vertical as said in problem.special type And like all previous problems solve completely.of triangularpyramid in whichbase sides & o’1slant edges are o’ o’equal in length. TLSolid of four faces. a’ a’1Like cube it is also 90 0described by One X a’ b’ b’ c’ b’1 c’ c’1 Y dimension only.. 450Axis length c c1 c1generally not given. a o o1 a1 o1 b1 b b1 a1
Problem 13.19: Draw the projections of a cone, base Steps45 mm diameter and axis 50 mm long, when it is (1) Draw the TV & FV of the cone assuming its base on the HPresting on the ground on a point on its base circle (2) To incline axis at 30º with the HP, incline the base at 60º with HPwith (a) the axis making an angle of 30º with the HP and draw the FV and then the TV.and 45º with the VP (b) the axis making an angle of (3) For part (a), to find β, draw a line at 45º with XY in the TV, of 5030º with the HP and its top view making 45º with the mm length. Draw the locus of the end of axis. Then cut an arc ofVP length equal to TV of the axis when it is inclined at 30º with HP. Then redraw the TV, keeping the axis at new position. Then draw the new FV (4) For part (b), draw a line at 45º with XY in the TV. Then redraw the TV, keeping the axis at new position. Again draw the FV. 30º 60ºX Y 45º β 45º
Problem 1. A square pyramid, 40 mm Solution Steps : Triangular face on HP, means it is lying on HP:base sides and axis 60 mm long, has a 1.Assume it standing on Hp.triangular face on the ground and the 2.It’s TV will show True Shape of base( square) 3.Draw square of 40mm sides with one side vertical as TV &vertical plane containing the axis makes taking 60 mm axis project FV. ( an isosceles triangle)an angle of 450 with the VP. Draw its 4.Name all points as shown in illustration. 5.Draw 2nd FV in lying position i.e. o’c’d’ face on xy. and project it’s TV.projections. Take apex nearer to VP 6.Make visible lines dark and hidden dotted, as per the procedure. 7.Then construct remaining inclination with the VP ( VP containing axis is the center line of 2nd TV. Make it 45º inclined to o’ xy as shown take apex near to xy, as it is nearer to VP) & project final FV. o’ a1 d1 60 o1X Y a’ a’ d’ b’ c’ b1 c1 d’ 45º b1 a1 b’ c’ a 1 b o o a1 40 o1 d c c1 1 b d1 1 d For dark and dotted lines1.Draw proper outline of new view DARK. 2. Decide direction of an observer. c13. Select nearest point to observer and draw all lines starting from it-dark.4. Select farthest point to observer and draw all lines (remaining)from it- dotted.
Problem 11: Solution Steps:Draw the projections of a cone base 50 mm Resting on HP on one generator, means lying on HP: 1. Assume it standing on HP.diameter and axis 75 mm long, 2.It’s TV will show true shape of base (circle)lying on a generator on the ground with the top 3.Draw 50 mm dia. circle as TV &view of the axis making an angle of 45º with taking 75 mm axis project FV. (a triangle)the VP. 4.Name all points as shown in illustration. 5.Draw 2nd FV in lying position i.e. o’e’ on XY, and project it’s TV below XY. 6.Make visible lines dark and hidden dotted, as per the procedure. 7.Then construct remaining inclination with Vp ( generator o1e1 45º to XY as shown) & project final FV. o’ a’ a1 ’ h’b’ h1’ b1’ c’g’ g1’ c1 ’ d’f’ f1’ d1’ X a’ h’b’ c’ g’ f’ d’ e’ e’ o’ e1 ’ o1’ Y g1 45º g o1 h f f1 h1 g1 h1 a e e1 a1 o1 a1 f1 d1 b1 b1 b d e1 c c1
Solution Steps:Problem 3: Resting on Vp on one point of base, means inclined to Vp:A cylinder 40 mm diameter and 50 mm 1.Assume it standing on Vp 2.It’s Fv will show True Shape of base & top( circle )axis is resting on one point of a base 3.Draw 40mm dia. Circle as Fv & taking 50 mm axis project Tv.circle on Vp while it’s axis makes 450 ( a Rectangle)with Vp and Fv of the axis 350 with Hp. 4.Name all points as shown in illustration. 5.Draw 2nd Tv making axis 450 to xy And project it’s Fv above xy.Draw projections.. 6.Make visible lines dark and hidden dotted, as per the procedure. 7.Then construct remaining inclination with Hp ( Fv of axis I.e. center line of view to xy as shown) & project final Tv. 4’ 4’d’ d’ 4’ d’ 3’ 3’ 1’ c’ a’ c’ 3’ c’ 1’ a’ 1’ a’ 2’ 2’ b’ X b’ 2’ 350 b’ Y a bd c 450 c c1 d1 b1 bd a1 3 a 3 4 2 24 1 24 3 1 1
Solution Steps : 1.Assume it standing on Hp but as said on apex.( inverted ).Problem 4:A square pyramid 30 mm base side 2.It’s Tv will show True Shape of base( square) 3.Draw a corner case square of 30 mm sides as Tv(as shown)and 50 mm long axis is resting on it’s apex on Hp, Showing all slant edges dotted, as those will not be visible from top.such that it’s one slant edge is vertical and a 4.taking 50 mm axis project Fv. ( a triangle)triangular face through it is perpendicular to Vp. 5.Name all points as shown in illustration.Draw it’s projections. 6.Draw 2nd Fv keeping o’a’ slant edge vertical & project it’s Tv 7.Make visible lines dark and hidden dotted, as per the procedure. 8.Then redrew 2nd Tv as final Tv keeping a1o1d1 triangular face perpendicular to Vp I.e.xy. Then as usual project final Fv. a’ a’1 a’ b’d’ c’ b’d ’ d’1 b’1 c’ c’1 X o’ o’ o’1 Y d d1 d1 c1 a b o c a1 o1 b1 c1 a1 1 b1 o
FREELY SUSPENDED SOLIDS:Positions of CG, on axis, from base, for different solids are shown below. H CG H/2 CG H/4 GROUP A SOLIDS GROUP B SOLIDS ( Cylinder & Prisms) ( Cone & Pyramids)
Solution Steps:Problem 7: A pentagonal pyramid In all suspended cases axis shows inclination with Hp.30 mm base sides & 60 mm long axis, 1.Hence assuming it standing on Hp, drew Tv - a regular pentagon,corner case.is freely suspended from one corner of 2.Project Fv & locate CG position on axis – ( ¼ H from base.) and name g’ and base so that a plane containing it’s axis Join it with corner d’remains parallel to Vp. 3.As 2nd Fv, redraw first keeping line g’d’ vertical.Draw it’s three views. 4.As usual project corresponding Tv and then Side View looking from. LINE d’g’ VERTICAL d” o’ d’ c’e’ e” c” FOR SIDE VIEW g’ H a’b’ a” b” g’ H/4 o” IMPORTANT: a’ b’ c’ e’ d’ Y X When a solid is freely e1 e suspended from a a1 corner, then line a d1 joining point of o do 1 contact & C.G. b b1 remains vertical. c c1 ( Here axis shows inclination with Hp.) So in all such cases, assume solid standing on Hp initially.)
Solution Steps: Problem 8:1.Assuming it standing on Hp begin with Tv, a square of corner case. A cube of 50 mm long edges is so placed2.Project corresponding Fv.& name all points as usual in both views. on Hp on one corner that a body diagonal3.Join a’1’ as body diagonal and draw 2nd Fv making it vertical (I’ on xy) through this corner is perpendicular to Hp4.Project it’s Tv drawing dark and dotted lines as per the procedure. and parallel to Vp Draw it’s three views.5.With standard method construct Left-hand side view.( Draw a 450 inclined Line in Tv region ( below xy).Project horizontally all points of Tv on this line and reflect vertically upward, above xy.After this, drawhorizontal lines, from all points of Fv, to meet theselines. Name points of intersections and join properly. a’’ a’For dark & dotted lineslocate observer on left side of Fv as shown.) d’’ b’’ b’d a’ b’d’ c’ ’ c’ c’’ X 1’ 1’ Y d d1 1’ a c a1 c1 b b
Problem 9: A right circular cone, This case resembles to problem no.7 & 9 from projections of planes topic.40 mm base diameter and 60 mm In previous all cases 2nd inclination was done by a parameter not showing TL.Likelong axis is resting on Hp on one Tv of axis is inclined to Vp etc. But here it is clearly said that the axis is 400 inclinedpoint of base circle such that it’s to Vp. Means here TL inclination is expected. So the same construction done in thoseaxis makes 450 inclination with Problems is done here also. See carefully the final Tv and inclination taken there.Hp and 400 inclination with Vp. So assuming it standing on HP begin as usual.Draw it’s projections. o’ o’1 o’ a’1 h’1 a’ b’1 h’b g’1 c’1 ’c ’g’ f’1 d’1 X a’ h’b’ c’ g’ f’ d’ e’ 450 d’f ’ e’ e’1 y Axis True Length g g1 o1 400 h f h1 f1 Axis Tv Length d1 c1 a e a1 1 e1 o1 e1 Locus of f1 1 b1 Center 1 b1 d1 b d c c1 g1 a1 h1 Axis Tv Length
Problem 10: A frustum of regular pentagonal pyramid is standing on it’s larger baseOn Hp with one base side perpendicular to VP. .Draw it’s FV & TV.Project it’s Aux.TV on an AIP parallel to one of the slant edges showing TL.Base side is 50 mm long , top side is 30 mm long and 50 mm is height of frustum. Fv AIP // to slant edge 1’ 2’5’ 3’4’ Y1 Showing true length i.e. a’- 1’ 4 5 TL 3 1 2 X a’ b’ e’ c’ d’ Y Aux.Tv e d1 c1 d e1 Tv 5 4 X1 a1 b1 a 1 3 2 c b
Problem:13.25 A pentagonal prism is resting on one of the corners of its base on the H.P. The longeredge containing that corner is inclined at 45º to the H.P. The axis of the prism makes an angle of 30º tothe V.P. Draw the projections of the solid. Also draw the projections of the solid when the plan of the axis is inclined at 30 to the xy. Take the sideof the base 30 mm and height 70 mm. 3’ o’ 4’ 3 1’ 4 1’ 2’ 3’ 1’ 5’ 4’ 2’ 5’ 2 1’ 5 1’ 1’ 1 1’70 c1’ d 1’ c’ d’ b’ e’ b 1’ e1’ 45ºX a’ b’ c’ a’ a1’ Y e’ d’ 5 1 51 e1 1 e 1 5 d 41 d1 30º 4 4 108º 11 a1 β1 e1 a o 30 2 a1 1 108º 1 c 31 c1 3 1 d b 3 21 b1 1 2 b 1 c1
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