Elliptical wing trouble for RC glider

I have a plan form for an elliptical wing and I have 9 airfoil sections from tip to tip.
I have tried to do a 2 rail sweep, but the surface is crossing over from top to bottom.
Attached it the front view of the surface that has been created.

any help to rectify this would be greatly appreciated.


Btw. If a this a GH question?

This is very simple to fix but no one can do anything until you give us the GH model that is failing for you - with airfoil sections and rails geometry internalized (preferably) or referenced in a Rhino file.

check your aerofoil section curves all have the same direction and their start points are all in the same place e.g. right on the nose

Use Rhino to show the curve directions

I figured it out.

My trailing edge line that i was using as a rail for the sweep 2 rail was in-between the open trailing edge of the airfoil.
I created a new line for the rear rail that now connects to the top surface of the airfoil trailing edge.

It sounds to me like you have mis-diagnosed the problem. More likely it was the direction of the rail curve that caused a problem, as @martynjhogg said, and you fixed that accidentally when you re-created that rail.

Without any code posted, this thread is useless to anyone who wants to learn from your experience.