I can't deduce the third view of an engineering drawing

[AhmedHesham]

Hi
What are the general algorithmic steps of producing a third view from existing two. I can't do it for all cases. So I am searching for an algorithm to follow.
Famous books don't pay a lot of attention to the subject. But in my school it is ! Can someone please help me with the steps. And by the way I believe in my mental ablities so don't say the problem within me. I believe everyone can do it!

 

[berkeman]

I can't do it for all cases.

Are you sure it can be done at all? Can you show some cases where you have been able to do it?

http://getdrawings.com/img2/3-views-of-isometric-drawing-52.jpg

 

[AhmedHesham]

I c

Are you sure it can be done at all? Can you show some cases where you have been able to do it?

http://getdrawings.com/img2/3-views-of-isometric-drawing-52.jpg

View attachment 257389

I can visualize this

 

[berkeman]

I can visualize this

No, my point is that there is information in each of the 3 views, and for some objects, you need all 3 views to understand the part. If you only have 2 views, then I don't think you can say that you will always be able to construct the 3rd view.

 

[AhmedHesham]

No, my point is that there is information in each of the 3 views, and for some objects, you need all 3 views to understand the part. If you only have 2 views, then I don't think you can say that you will always be able to construct the 3rd view.

In some books I read there is a removed view that you want to deduce and construct and in my school there a whole chapter dedicated to the subject I know it's not that interesting and not important but my dang school want it.

 

[berkeman]

there is a removed view that you want to deduce and construct

Can you attach a file with a couple of drawings? I'm not sure that I understand what you mean by "removed view". Do you mean modifying a view to show a portion of a part removed?

 

[AhmedHesham]

Can you attach a file with a couple of drawings? I'm not sure that I understand what you mean by "removed view". Do you mean modifying a view to show a portion of a part removed?

In a book named technical drawing for engineering graphics there is a portion named projecting a third view in which he does it and construct a third view from two with the help of the 3d isometric but in my school we do it without the isometric check the book if you can

 

[berkeman]

construct a third view from two with the help of the 3d isometric

That's going to help a lot having the isometric view (not in all cases, depending on the perspective of the iso view).

I don't have your book. What is a "removed view"?

 

[AhmedHesham]

No I really mean it
Deduce a third view from available two views

 

[AhmedHesham]

The book of my school is in Arabic I can't upload it

 

[Merlin3189]

As others have said and also in other threads (search "orthographic") it is impossible in some cases. Consider two views which are both just a rectangle: the object could be a cuboid, a triangular prism or a cylinder, at least.
I suppose that if you are given only two views, the assumption must be that all significant features are visible and the third view is the simplest possible that is compatible with the other two.

Would it help to see a suggested procedure for developing the third view of, say Berkeman's drawing?.

 

[AhmedHesham]

As others have said and also in other threads (search "orthographic") it is impossible in some cases. Consider two views which are both just a rectangle: the object could be a cuboid, a triangular prism or a cylinder, at least.
I suppose that if you are given only two views, the assumption must be that all significant features are visible and the third view is the simplest possible that is compatible with the other two.

Would it help to see a suggested procedure for developing the third view of, say Berkeman's drawing?.

I agree with you
But it may be like constructing the projections of a point... If you have two the third projection of the point is completely specified.
It's actually essential in my school... A whole chapter is dedicated to it.

 

[Merlin3189]

It works for a point. But a line is a collection of points for which you can only definietly match the end points. There is no way of projecting individual points on the line, except the ends, because you don't know where they are.

 

[AhmedHesham]

It works for a point. But a line is a collection of points for which you can only definietly match the end points. There is no way of projecting individual points on the line, except the ends, because you don't know where they are.

Yes that's exactly the problem
But how can you explain that my school made a whole chapter for it and that they will be in the exam.