the problem is that I could not find any solution for lofting the ramp-surface between two spirals. It works when the inner spiral goes from large two small radius and the outer does the same. In this case I need different run width on my ramp, so the iner spiral should go from large to small and the outer spiral from small to large radius. I alredy tried to use Sweep 1 and 2, Patch, nothing worekd. Thanks a lot for your help.
I present the issue by pictures and the gh-file belowForum-LoftingTwoSpirals.gh (32.1 KB)