concept of curves on sketch.

[Tarkus]

hello to all
No problem:
If I want to project the entities of a sketch on a curved surface, I have all the necessary tools in 3d sketch: project on surface -> envelope.
But if I wanted to do it backwards, I mean, to lay the profile of something curved
on a 2d sketch, for example the profile of a helicoid on a tangent plane to the helid itself, how do I?
with 3d sketch tools I couldn't...

 

[VigZ]

You should do it.. . .

 

[Tarkus]

You should do it.. . .

No, I don't think I explained:
Then we suppose that I have a cylinder and a tangent plane to the surface of the cylinder.
I do a sketch on this plane: a tilted line of n degrees compared to the projection of the cylinder axis.
3d sketch.
project on surface -> envelope.
so I can project my sketch line to the surface of the cylinder and get a helid with a longer or longer development. Okay?

Well, I'm wondering if you can do the opposite thing, that is, having a helicoid with a single snitch, if I can project it "srolling", the evolving curve on a plane, and have the straight line of my example upstairs.
I need to figure out what track creates that helid spire if I roll it physically on a plane...

 

[rf.infissi@libero.it]

I take this old discussion for a very similar problem.
I have an ipt curtain created by a surface with splines and then I gave thickness.
I would like to represent on a 2nd floor the part, but not projected but unexplained, as it is done for lelamas to understand us, can someone tell me how to achieve the desired result?