Projections Of Lines

Projections Of Straight Lines

Important terns to draw projections of straight lines

• Information regarding a line is...it's length, The position of Its ends with HP and VP, Its inclinations with HP and VP will be given.


• To draw its projections means FV and TV.

Simple cases of the line

1. Line perpendicular to HP and parallel to VP ( A vertical line )


2. Line parallel to both HP and VP.


3. Line inclined to HP and parallel to VP.


4. Line inclined to VP and parallel to HP.


5. Line inclined to both HP and VP.

1 ] Line perpendicular to HP and || to VP ( A vertical line )

note: Fv is a vertical line Showing True Length & Tv is a point.

 

2 ] Line parallel to both HP and VP

note: Fv & Tv both are parallel to XY  & both show TL ( true length).

3 ] Line inclined to HP and parallel to VP.

note: Fv inclined to XY & Tv parallel to XY.

4 ] Line inclined to VP and parallel to HP.

note: Tv inclined to XY & Fv parallel to XY.

5 ] Line inclined to both HP and VP.

note: Fv as a image on Vp. & Tv as a image on Hp

Both the Fv & Tv are invlined to XY, NO view is parallel to Xy.

Both the FV & Tv are reduced lengths, NO view show True Length ( T.L ).

Fv is seen on Vp clearly, To see Tv clearly, Hp is rotated 90º  downwards hence it comes below Xy.

1 ] Orthographic projections means Fv & Tv of line AB are shown below, with their apparent inclinations α & β

Here Tv is not || to XY line Hence it's corresponding Fv a' b' is not showing True Length & True inclination with HP.

2 ] When Fv & Tv known, how to find True Length. ( View are rotated to determine True Length & it's inclinations with Hp & Vp).

In the diagram, Tv is rotated and made || to Xy line. Hence it's corresponding FV  a' b₁' is showing True Length & True inclination with HP.

3 ] when True Length is known, How to locate Fv & Tv.( Component a-1 of TL is drawn which is further rotated to determine Fv)

Here a-1 is a component of TL ab1 gives length of Fv. Hence of a' and further rotated to get point b'. a' b' will be Fv. Similarly drawing component of other TL( a' b₁' )Tv can be drawn.

Please write comments if you find anything incorrect and if you have any queries about this topic or you want to share more information about the topic discussed above.