I’ve had the time to look at this now and believe it’s much ado about nothing. My reply in the other thread about using just one section curve was very close to the truth.
After much experimentation, I find this morning is that one section curve works fine except for a twist at the very end. I don’t know what you and @magicteddy did to fix this? In the end, I used a separate sweep on the last section (yellow) that minimizes the twist, but it’s still there and I don’t see how it can be avoided? All the straight sections have no twist except for that last one.
BA_rotation_2023Mar2a.gh (21.9 KB)