Cone Roof - Helical Radius along face of Cone

[rwhitt0724]

Hello everyone. I have started a project and have a somewhat unusual condition. I know this is not a detailing site, or an engineering site, but I figured there are some smart fellows on here that may be able to give a little input to this. I have a structure with a Conical Roof. We are putting a parapet around this roof. With the parapet, we are also going to create 4 individual structures that direct water/rain flow to scuppers that will be fabricated into the parapet. Below is a sketch of our condition. I was wondering if anyone knew how to get the shape of a line that follows the face of a cone. Obviously, this line is not projected to the center of the cone, so it is not just a straight line. I am imagining either a radial cut piece, or a complex/multiple radial cut piece. I don't really know how to put it into words exactly.... Take a look at the sketch and ask away. Also, if anyone knows a website where I may be able to do a little more research into something like this that would be great. Anyways... Here you go...

 

[SEANT]

I'm interpreting the sketch like so:

ConeRoof.dwg

[fuccaro]

If you wish a helix on a cone: http://www.cadtutor.net/forum/showthread.php?78-Get-your-Helix-here!&highlight=cone%2Chelix

That thread is 100 years old, post here and I will clean the code if you are interested in.

[rwhitt0724]

Fuccaro, I honestly have no idea what that thread means, lol.... I am not very familiar with LISP routines.

 

SEANT, you are exactly correct in your interpretation. What I am trying to do, is fabricate those flat panels that you see going from that perimeter wall, down overlapping the cone roof. I am able to generate the peak of that piece and the helix along the perimeter wall but I am having trouble understanding/generating the radius/helix that will actually be resting along that cone roof. I am going to play around with it right now to see what I can come up, but yes SEANT, you are exactly correct in that interpretation.

[JD Mather]

What I am trying to do, is fabricate those flat panels that you see going from that perimeter wall, down overlapping the cone roof.

... I am having trouble understanding/generating the radius/helix that will actually be resting along that cone roof. .

 

This entire assembly would be pretty easy using Autodesk Inventor sheet metal tools (will automatically give you the flat patterns).

 

In AutoCAD to interpret those interestions you might

1.Change your active color

2. Run the xedges command (this will create curves at all of the edges - turn off the solid and then delete the edges you are not interested in).

[scj]

If I understood your problem correctly, so the bounding polylines of the unfolded surface area will give you the "wires" on the cone surface.

Regards

Jochen

ConeRoof-scj.dwg

[rwhitt0724]

The only discrepancy I can see with both of the above DWG files, is that the sort of "roof dormer" we are making (for lack of a better description), the 2 pieces of sheet steel required, will not be rolled. We are trying to make a standard sort of gable style dormer; 2 sloped sides to form a peak. They will not be rolled in the sort of crescent shapes it appears these drawings show.