Hi Psygorn, so yes your curve tangents are all set up like you thought. The problem is that will only make the network surface to be tangent at those particular spots. At the interior areas the surface shape will be a kind of blending of all the curves. You can kind of get a feel for this if you turn on surface control points.
Sweep can be better for this type of shape instead of Network, especially for a 3 sided layout.
I've attached an example file, if you load the file SweepTangent.3dm you can select this curve for the profile:
Then these as the 2 rails:
Then enable the "Maintain tangent" option:
A sweep made with that option will keep all the cross sections generated for the sweep to be on parallel planes, like this:
This kind of construct then has the full surface to be tangent at the centerline, so it can be mirrored ok:
If you turn on surface control points for the Network you can see that the generated surface won't have that kind of sections on parallel planes type structure, it will be influenced by things like the different lengths of the curves.
To use Network it's making a weird shape because for Network the curves have to form a regular 2D grid, sort of like a set of latitude and longitude lines, so you'll need to join together some pieces so it has that type of layout. So for your case here that would be like this:
If you open the attached NetworkExample.3dm file and select all the curves and then run Network that should work.
Another layout that would work for Network is to have these 3 as separate curves, and then the bottom one joined together, then that makes a Network with the "pole" at the tip:
If you turn on surface control points for each of these Network results you'll see that on the first one there are "poles" at the ends, and the other one has one "pole" at the top:
The result you were getting that was chaotic or didn't finish calculating is because Network was not able to get a regular "latitude/longitude" layout from those curves.
Hope this helps!
- Michael