Sweep a crosssection geometry along a spline

Hello,
I am trying to convert a spline path into something more like a nerve bundle with multiple compartments following the path. ThickenWire works if I am keeping to a simple crosssection of concentric circles, but I want to move beyond that.
I've tried starting out with sweeping a circle along the path of the spline, but I get the error that the sweep results in a selfintersecting surface. How do I constrain the normal of the crosssection to follow the path as well?
And then with the next step in complexity, what would be done differently to sweep a crosssection template with multiple geometries along the spline?
My apologies if this is in the wrong section, but it seemed mostly CAD related to start with, and the tutorials I've looked at only import the geometry.
Extra points for the associated python scripting commands
Thank you. 
Hi, when sweeping an object along a path, the normal of the crosssection should in principle follow the path. This, however, does not prevent having selfintersections in locations where the curvature of the path is too large compared to the size of the crosssection.
The best way to experiment (different geometries, different paths, etc...) is to use the Python API:
import s4l_v1.model as model from s4l_v1.model import Vec3 import XCoreModeling spline1 = model.CreateSpline([Vec3(0,0,0), Vec3(50,0,0), Vec3(50,50,50)]) section = model.CreateCircle(Vec3(0,0,0), Vec3(1,0,0), 10) region1 = XCoreModeling.SweepAlongPath(section, spline1, make_solid=True)
