I need to create a helical curve that is normal to an existing helical curve. A spiral on a spiral so to speak. I have found several curve equations that are close, but what usually happens is that the secondary curve is not swept normal to the primary curve. The primary curve is created by cylindrical equation like this: r = 0.75 theta = 360 * t * 4.5 z = 0 - 19.05 * t
It is the equation that sweeps the secondary curve that eludes me. Surely, someone must have done this before. Any ideas?