About Helix parameter (helix: constant angle with a fixed direction), I think that:
Pitch is in fact step (gap, increase, distance between two coils) if helix is cylindrical. Pitch should be an angle.
Heigth is right when the direction is Z and helix is cylindrical, otherwise is total length or ?
Conical helix is in fact Conical spiral of Pappus or not?
Radius with conical helix is Start radius (radius is not constant).
What do you think? This is also useful for the wiki.