Fusion 360 - Faceted Ring with T-Splines (mostly)

Modeling the outer surface of a faceted/polygonal Ring with T-Splines.
Circular symmetry makes this quick work.
The surface is then used as a splitting tool for a solid modeled ring.
Here is a link to the original thread on the Fusion360 forum:
forums.autodesk.com/t5/fusion-360-design-validate/how-to-facet-a-model-a-certain-way/m-p/11568389/highlight/false#M286159