Difference between 1st angle & 3rd angle projection।#firstangleprojection & #thirdangleprojection.

Skill Tech Drawing
Skill Tech Drawing
17.9 هزار بار بازدید - پارسال - Difference between 1st angle &
Difference between 1st angle & 3rd angle projection।#firstangleprojection & #thirdangleprojection .
Engineering Drawing me Orthographic projection sikhna bahot jaruri hai. Hamne 1st aur 3rd angle sikhe, lekin oon donome kya antar hai wo iss videome samazme ayega.
After studying the theory of Orthographic projection we have studied the Planes for projection and how the 1st & 3rd angles are formed.We also studied how the views are formed in both (1st & 3rd angle).Here we are going to distinguish between the First & Third angle of projection.
(1)In First angle V.P.,H.P. & A.V.P. are opaque whereas in Third angle these planes are transparent.
(2)H.P. of right side goes down in 1st angle that is why the T.V. on H.P. comes below the F.V. &  as A.V.P. goes right, the S.V. seen from left comes to the right of F.V. and in the 3rd angle as H.P. goes up the Top view on H.P. comes on the upper side of F.V. & side when seen from left comes left side of F.V. as A.V.P. goes left.
(3)In First angle portion which is above H.P. & in front of V.P. the object is kept in between observer and plane because planes are opaque.This is light and shadow method whereas in Third angle portion which is below H.P. & behind V.P. we can keep the transparent plane between observer & object.So it is called see & draw method.
Besides these above mentioned points while differentiating both we have to study the standard symbols representating the First angle and also the Third angle of projection.
In actual practice while drawing the views we may jumble in placing the position of views.Therefore, initialy confirm in an Isometric block where the observer is standing to see the front portion.Third angle is simple to understand because this is see & draw method.Hence draw F.V. below the reference line, draw the position of T.V. above the F.V. and if side seen from left draw S.V. left side of F.V. and vice a versa.And then simply cross change the position of views to form the 1st angle projection.
Important Topics Covered :-
1.Theory of planes and formation of 1st & 3rd angle.
2.Assumptions for 1st angle as well as 3rd angle.
3.How the position of views in both angles differ.
4.Actual main points showing the difference in 1st & 3rd angle.
5.Difference in symbol & actual practical difference while projecting any object on drawing sheet without jumbling (from 3rd angle to 1st angle).
#1st&3rdangledifference
#orthographic_projection
#firstangleprojection
#thirdangleprojection
#machinedrawing
#engineeringdrawing
#technicaldrawing
#skilltechdrawing
#sanjaykhair
#orthographicprojection
#difference
#distinguish
پارسال در تاریخ 1402/02/22 منتشر شده است.
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