Hi urban - I think you've got your curves there selectedin the wrong order.

For rail revolve you want to have the profile be the curve that touches the pivot axis, and the closed curve going around the whole circumference should be the rail curve and picked 2nd instead of picked 1st.

So start out with just the curve in the Front view selected - then run rail revolve and then for the rail curve select the closed curve in the top view, then the pick the revolve axis points.

The result you're getting is because it's trying to revolve the closed curve around the shorter one when I think you want the opposite to happen.

- Michael