Sweep2 Bad Result

Sometimes, I got like this not good result.
I checked directions of curve properly.

Rhinoceros (5.9.40609.20145, 2014/06/09)

sweep2-error.3dm (235.0 KB)

The second rail is not touching the profile curves. I think in this case you’re better off with Sweep1

How does the surface in the attached file look?

Work-around used to create it.

  • Close the sections. Create line segments from the ends of the sections to the rail using the Perp OSnap. Use join to create two closed polylines.
  • Sweep2 using the closed sections.
  • Explode the polysurface from Sweep2 and delete the unwanted surfaces
  • Join the remaining surfacessweep2-error_DC1.3dm (2.4 MB)

or another aproach.

work around is;

cut inner rail excesses.
place it where it touches the section ends

sweep2_another aproach.3dm (353.9 KB)

Thanks, this tips was good for me.

But another CAD ,open section sweep works very good even if do not touch the lines exactly.

This is little disappointing function of Rhino, So I hope it will be fixed in Rhino version 6.