PROBLEM 1 :A square pyramid, 40 mm base sides and axis 60 mm long, has a triangular face on the ground and the vertical plane containing the axis makes an angle of 450 with the VP. Draw its projections. Take apex nearer to VP.
Construction
Triangular face on Hp , means it is lying on Hp :
Step 1 . Assume it standing on Hp.
Step 2 . It’s Tv will show True Shape of base( square)
Step 3 . Draw square of 40mm sides with one side vertical Tv & taking 50 mm axis project Fv. ( a triangle)
Step 4 . Name all points as shown in illustration.
Step 5 . Draw 2nd Fv in lying position i.e. o’c’d’ face on xy. And project it’s Tv.
Step 6 . Make visible lines dark and hidden dotted, as per the procedure.
Step 7 . Then construct remaining inclination with Vp ( Vp containing axis is the center line of 2nd Tv. Make it 450 to xy as shown take apex near to xy, as it is nearer to Vp) & project final Fv.
Triangular face on Hp , means it is lying on Hp :
Step 1 . Assume it standing on Hp.
Step 2 . It’s Tv will show True Shape of base( square)
Step 3 . Draw square of 40mm sides with one side vertical Tv & taking 50 mm axis project Fv. ( a triangle)
Step 4 . Name all points as shown in illustration.
Step 5 . Draw 2nd Fv in lying position i.e. o’c’d’ face on xy. And project it’s Tv.
Step 6 . Make visible lines dark and hidden dotted, as per the procedure.
Step 7 . Then construct remaining inclination with Vp ( Vp containing axis is the center line of 2nd Tv. Make it 450 to xy as shown take apex near to xy, as it is nearer to Vp) & project final Fv.
PROBLEM 2 : A cylinder 40 mm diameter and 50 mm axis is resting on one point of a base circle on Vp while it’s axis makes 450 with Vp and Fv of the axis 350 with Hp. Draw projections.
Construction
Resting on Vp on one point of base, means inclined to Vp:
Step 1. Assume it standing on Vp.
Step 2. It’s Fv will show True Shape of base & top( circle ).
Step 3. Draw 40 mm diameter. Circle as Fv & taking 50 mm axis project Tv. ( a Rectangle)
Step 4. Name all points as shown in illustration.
Step 5. Draw 2nd Tv making axis 450 to xy And project it’s Fv above xy.
Step 6. Make visible lines dark and hidden dotted, as per the procedure.
Step 7. Then construct remaining inclination with Hp ( Fv of axis I.e. center line of view to xy as shown) & project final Tv
Resting on Vp on one point of base, means inclined to Vp:
Step 1. Assume it standing on Vp.
Step 2. It’s Fv will show True Shape of base & top( circle ).
Step 3. Draw 40 mm diameter. Circle as Fv & taking 50 mm axis project Tv. ( a Rectangle)
Step 4. Name all points as shown in illustration.
Step 5. Draw 2nd Tv making axis 450 to xy And project it’s Fv above xy.
Step 6. Make visible lines dark and hidden dotted, as per the procedure.
Step 7. Then construct remaining inclination with Hp ( Fv of axis I.e. center line of view to xy as shown) & project final Tv
PROBLEM 3 : A pentagonal pyramid 30 mm base sides & 60 mm long axis, is freely suspended from one corner of base so that a plane containing it’s axis remains parallel to Vp. Draw it’s three views.
Construction
In all suspended cases axis shows inclination with Hp.
Step 1. Hence assuming it standing on Hp, drew Tv - a regular pentagon,corner case.
Step 2. Project Fv & locate CG position on axis – ( ¼ H from base.) and name g’ and Join it with corner d’
Step 3. As 2nd Fv, redraw first keeping line g’d’ vertical.
Step 4. As usual project corresponding Tv and then Side View looking from.
In all suspended cases axis shows inclination with Hp.
Step 1. Hence assuming it standing on Hp, drew Tv - a regular pentagon,corner case.
Step 2. Project Fv & locate CG position on axis – ( ¼ H from base.) and name g’ and Join it with corner d’
Step 3. As 2nd Fv, redraw first keeping line g’d’ vertical.
Step 4. As usual project corresponding Tv and then Side View looking from.