Simple square to round transition

Does anyone know how to make a drawing of an unfolded Square to round
duct piece that has real fold lines shown so that someone can actually
fabricate the piece?
The unfolded default sheet metal piece has no such markings.
I was wondering if anyone has solved this problem already and can
suggest to me the technique.

thx.
Biebz.

 

Your assumption is that this is simple. It isn't.

 

The best I can say is that you can do Lofts in SolidWorks of the exact
size square and circle you want, and then image how you would break up
the loft into segements which could be semiconically developed, piece
by piece.

As TOP noted..."simple. It isn't"

I've seen pieces done like this in military devices where they can
spend the money to do it when they must, and they often investment cast
the needed piece. If the sizes are compatible, maybe explosive hydro
forming can be used.

Bo

 

Is this what you're looking for?

http://img380.imageshack.us/img380/6909/s2r010uh.jpg

 

I am Edoardo from Italy leaving in Beijing.
It is long time I am looking how to do exactly that solids with
autocad.

Please help me