Hi James,
thanks for posting I'd forgotten about that but it as given me an idea for aligning the frames on the globoid helix.
Is it possible to have a circle as the attractor around the waist of the globoid helix and for the frames to align to nearest point on the circle.
Your mpatharray aligns them along the helix solving one problem for me but the frames then have to be aligned to the wheel centre which could be represented by the circle.
Cheers
Barry