I have created a 3d model of a helix with very small angle.  The basic dimensions of the helix are Inner Edge 820mm diameter, Outer diameter edge 940mm , so the width is 60mm and thickness of the profile 11.6mm.  The helix in the model is shown at a pitch of 60mm and 1.5 turns making 90mm high.

I have also produced a ring wihich is at the base of the helix. The important note here is that the upper face