Hi Terje, there isn't really an easy way to do this currently in MoI since right now there isn't an option to make a helix that follows a curve rather than being a straight helix.

I'd like to add this eventually but it won't be in the V1 version of MoI.

For now I'd recommend doing this shape using Rhino instead - it does have an option for a helix that follows a curve.

- Michael