Solid extrusions with Rhino

Something like this?

 

The example above was created using the Sweep1 command. The distorted "circle" was the rail, and the closed "L" curve was the section. I used the default "freeform" style.

 

AndreDesign the rail revolve is for creating a surface from a section, around a central axis, which is not a circle but is of a circular shape. I think what you are looking for is as Dcockey has shown in his example using the sweep 1 rail if its just a piping shape the same all the way along. You may use the sweep 2 rails if you wanted to change the way sectional shape orientated its self over the length of the finished surface. Another thing to keep in mind is the curvature of the rail line in relationship to the section size; to large a section on sharp curve and the surface will crease back on its self. If you are still having trouble maybe as daiquiri has suggested you post an example. The pic and file ( I used Dcockey sectional shape to keep the example similar, hope you don’t mind D) is of the examples I gave.

 

Can you draw a torus that follows the rail and subtract the portion that is not part of the design? That is how I do it in a-cad.

 

Hoytedow I am not sure what you mean by drawing a torus that follows a rail. Do you mean like a knot torus or something like a double torus?

 

Draw simple tori same circumference and cross-section as rail curve. Delete eveerything outside design criterion. Repeat as necessary until head stops hurting.

 

Perhaps you could post an example of what you are describing.

How do you "Delete eveerything outside design criterion" if you don't have other geometry to use for cutting or splitting?

 

Just draw a solid at the point where you want the torus to terminate and subtract it, like a 3d venn diagram.

 

Are you responding to Daiquiri's question in the first post which was resolved a month ago, or to andreDesign's question of two days ago?

Where did a torus enter into either question?

 

It was just additional info based on my limited knowledge of a-cad. I was responding to D's original question from an a-cad frame of reference.

Sorry.

 

Just wanted you guys to know this thread saved my *** yesterday when I went to design a curved stair railing to be CNC cut from wood. I remembered this thread after a half hour of cursing and grinding my teeth. The answer is simple (as always) when you just relax and think. Thanx for the great input.