Article and video by @DickBaardse
NX is a versatile CAD software in that there are many possible ways you can model geometry. Today, we will look at an alternative way to model helix-like structures. You can use Variational Sweep in a special way to achieve the results you desire.
There is a powerful yet little-known capability in Variational Sweep that makes it posssible to model a helix. You can vary the sketch depending on the position along the path. The sketch plane contains an expression that you can use inside the sketch.
Watch the movie below to see the steps.