Per-object rotation

I am trying to rotate the curve around a fixed axis (the axis should be the dotted line). I want to also rotate the next ones but I can’t find the rules.

This sounds like a new problem. I’ll split the reply into a new post. Please include a file that people can create and test their solutions in.

something like this? arc (7.7 KB)

Thank you very much for creating this post and for your advice. As you can see I was able to resolve the previous problems following your suggestions… what do you think not bad for someone who has never used grasshopper and is self learning?