Why 2nd and 4th angle projection not used ? | Difference between first and third angle of projection
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- เผยแพร่เมื่อ 28 ส.ค. 2020
- After watching this video you will know below points....
1. what is first and third angle projection
2. Difference between first and third angle projection
3. How to easily identify first and third angle projection on drawing
4. Why we don"t used second and fourth angle projection
#firstandthirdangleprojection
#orthographicprojection
Thank you for watching
Mechanical Design Adda
The reason, as far as I understand is that, we stick to 1st and 3rd angle projection methods, just for standardization purpose, so that instead of four different approaches, now we have to go with only one of two approaches. And, clock-wise "sounds good" than anti-clockwise rotation. In case of 2nd and 4th angles, overlap happens only when following clock-wise rotation of horizontal plane ( we do it to have both projections in the same 2-d plane, for sake of representing in a "paper"). If we rotate anti-clockwise, the issue with overlap goes away, and we get both views in same plane. But the results would be the same as rotating clock-wise for 1st and 3rd angle projections. This is just an opinion. Feel free to correct me or add more info on why we go with the choice.
Hi Ajay..... Good explain....you are right 👍❤️
According to the point where I can understand brother e've got you but i was stucked for answering
Hi Ajay,
I think there is a problem when we rotate anti-clockwise. The drawing will get upside-down.
If you rotate in anti clockwise then 1st and 3rd angle projection overlapping issues and you will get orthographic view in 2nd and 4th angle of projection
Your video’s are very knowledgeable for beginners
Nice explanations.
Thank You.
Good teaching . Go ahead 👍
Nice explain Sir
Bahut baar ye quadrant ke pange samajh mein nahi aate hai bahut dino tak... Lekin apne bahut achhe se bahut short time mein poora clarity se samjhaye ho... Thank you so much sir...🙏🙏🙏
Thank you Ishan.....
Very nice expln.
Good explanation
Perfectly explained. No doubt remaining.
Thank you for your comment.......stay connected
Good Art
Your video's are very knowledgeable for beginners
Thank you Mahantesh........
Why can’t we rotate the planes 90 degree anti-clockwise for 2nd and 4th angle of projection to get the views on the same plane of paper?
Hi Suresh, really good question,
We can do that by rotating the plane 90 deg anticlockwise we will get projection.
But in that case whatever the projection we are getting,if you compare with Clockwise first and third angle projection it will be same.
So 2nd angle projection act as a 3rd angle projection
And 4th angle act as a 1st angle of projection.
But we generally follow clockwise rotation considering standard one👍.
I hope you understood
& Thanks for valuable comment
Excellent explanation 👍👍
Thank you ☺️
Stay connected........
you have explained very well. but as far as 2 and 4 quadrants is concerned, why these two plans are not being used. can you elaborate more.
Thank you...Thakur
Overlapping is the only issue..
Because if you want a 2D view for that general rule is to rotate plane by 90° after projection and at that time it will overlap with other plane...
View will overlap and we unable to get projection on drawing..
Thank you..... keep watching
Why we rotate horizontal plane at c/w direction..?
Nice
Super sir
Any chance you’d be able to explain which ones are the front elevation, end elevation and plan view?
I have not understood your question
Do you want me to explain front, side and top views ?
Made easy for online class
Nice
I have viva in the evening
Know nothing
Now thanks to you something I know😂😭
Welcome ....keep watching
Nice explained sir 🙏🙏🙏
Thanks
You are welcome....... Stay connected..... Keep watching
@@MechanicalDesignAdda
Thanks
good
Nice explanation Sir
Thank you 💓
Please explain the part why do we need to rotate the horizontal plane clockwise ? What is the need.
To get the orthographic view (2D view)
Why should you rotate the horizontal plane clockwise ??
Hi,
Please check other comments
I have already replied
You will get the answer
Sir please reply...why in 3rd quadrant left side on left and righ on right ....not like the 1st left on right and righ on left .... please reply please it's so confusing ..any body help please
Hi Friend,
In first angle of method, we have
observer---object(body)---plane
In third angle of method, we have
Observer---plane---object(body)..
So our ultimate aim is to have a projection on plane to get a 2D view.
So that's the reason only.
For 1st angle method-- viewing from left, place view on right or vice versa
For 3rd angle of method-- viewing from left, place view on left or vice versa because now' plane is in the middle of observer and body...so projection is on observer side
I hope you got your answer......
Stay connected........ take care
@@MechanicalDesignAdda so that's it .it's just a rule... nothing to worry about thanks sir 😭
Why we rotate 90 degree angle along clock wise? Why clock wise why not anticlockwise?
It's standard practice that we are following
If we rotate anti clockwise we will get 2nd and 4th angle of projection and 1st and 3rd will overlap
So to avoid any confusion and everyone on the same page standard are fixed in angle of projection so that everyone can can same standard method and understand drawing
If we have number of option for angle of projection then it will create confusions among all
Sir you explain vary good but sir can make video in Hindi language? If possible?
Magan... Thanks for valuable comment
Yes I will upload in hindi also stay connected
Keep watching & keep learning
Problem s 1&3 quadrant s present sir
Legend watching this video in 2023😂
2024
Why should we rotate the axes for 2nd and 4th angle projection?
We need to rotate the horizontal plane in clock wise direction to get projection on drawing
We can't place views on drawing in 3D view
@@MechanicalDesignAdda ok sir got it👍
Why third angle projection is not used in Asian countries?
Why we need to rotate the plane in 2nd and 4th angle time ?
It's rule, so that we can get the orthographic view (2D view)
Please answer
Q1)the projection originated from from the eye ball and converted into 3d object to project a 2d image on the plane is the
(a) 1st angle projecetion (b) 3rd angle projection (c) 2nd angle projection (d) 4th angle projection
.
Q2) the projection originated from from the eye ball and converted into 3D object to project a 2D image on the plane is the
(A) 1st angle projecetion (B) 3rd angle projection (C) 2nd angle projection (D) 4th angle projection
First angle projection, second angle projection, third angle projection, and fourth angle projection are all different methods of representing a three-dimensional object on a two-dimensional plane in technical drawing, and they do not involve converting a projection from the eye into a 3D object.
The projection described in the question is called perspective projection, which is a type of projection commonly used in art, architecture, and computer graphics to create the illusion of depth and three-dimensionality in a two-dimensional image.
I hope you got an answer👍
@@MechanicalDesignAdda Thanks bro but i didnt get my answer
Ok, can you please rewrite your questions in some simple way so that I can understand what you want.
I will try to answer your questions 😊
@@MechanicalDesignAdda Sir it is the same question as it is and 2 times repeated in my test
Confusing to recognise
Why there are first and third angle projection?
Why we all can't go with only first angle projection? What is the significance of using first and third angle projection?
First and third angles are methods of representing drawing views only, country to country they will use the first or third method of projection.
@@MechanicalDesignAdda which angle projection is used in India?
Generally first angle projection is used in India and Europe countries. Third angle is used in America and Australia
Why we have to rotate plane in clockwise only.? Why not CCW..?
Hi Rakshith...
I already this in comments...
Please go through comments
Why we need to be rotate 90 degree for 2nd and 4th angle projections
To get the 2D view (orthographic view)
please make your concept clear because your explanation doesn't clarify 1st angle and 3rd angle symbol. your view of 3d model on 1st and 3rd angle projection is wrong. think about it please.
Overlapped means what ?
Overlapped means one object or view on another object or view
How to identify which measurements in direct view for any part diagram
Currently 3rd angle is used everywhere since 1st angle cads create confusions. Also not using 2nd and 4th angle is due to +ve and -ve values in same quadrants which is not possible for a product. Please remember how you use to make a graph when studying in school.
First and third angles are both are in used, it depends on the organisation, client and supplier which practice they are following so that everyone can understand drawing
Why we don't rotate vertical plane?
Generally we follow standards of rotating horizontal plane in clockwise direction.
we can't rotate vertical plane in Clockwise direction it will result in overlapped view
But if you rotate vertical plane in Anti clockwise it will give you orthographic view
We dont rotate vertical plane because, observer is watching the vertical plane as per standard. Soif you rotate vertical plane then observer can't see the projection plane any more. So we move horizontal plane inorder for the observer to see projection even after the rotation.
Bhai galat bataya hai yar tumne.
There is no rotation problem.
1st and 4th angle project are same ....
Except in 4th angle....top view is on the top.
Similarly 2nd & 3rd angle proj are same except... In 2nd angle top view is on bottom
Nahi Bhai, video me ekdam sahi information he.
Jab hum horizontal plane ko rotate karte he closewise direction me tab jake Hume view milate he.
2nd and 4th angle of projection me fv and tv overlap hote he isliye o method hum use nahi karte
Aasha karta hu me aapko samja Paya 😊
Jhanttu bna diya apni gndi english se aap achj khasi video ko
Thank you for comment
I will work on it ....
Question.
1. Why are we viewing from the right side only?
2. Why numbering the quadrants are in anti clock wise directions?
3. If we are viewing the 1st angle from right side why we can't view 4th angle from left side? And vice versa?
4. Here you explained about 2 planes (horizontal and vertical) where you impose the view. On which principal we are rotating the object for other views? If object is not rotated where are other planes? (A total of 6 planes have to be there).
In the angle of projection most things are standardized
Two planes are the imaginary transparent plane
We have two options 1 and 3rd angle of projection to get the 2D view
We need to follow standard because if we have number of option then we will get number result
Drawings are universally accepted so we need to take standard option we have so that everyone can understand and avoid confusion
To summarise all, to avoid confusion and maintain drawing standard we need to follow recommended standard practice of 1st and 3rd angle of projection👍
Let me know your point of view ☺️
@@MechanicalDesignAdda I know we are following standards based on some principles but my question is why? Clearing that will make the viewer more knowledgeable.
As I said, more options create confusions as drawing are referring all over the world
So the reason we are following standard practice in angle of projection is to confusion.
If we have no. Of option in angle of projection then everyone follow different different method and it will create confusion
As drawing goes in different departments and different steck holders