A vase named "Cog"

I wanted to design a vase, that would visually combine the strength of massive struts with finesse of a gentle curve.

There are two versions of the model:
* **cog.stl** is intended to be sliced in a regular way
* **cog_vase_mode.stl** needs to be sliced in _Vase Mode_, also known as _Spiralize Outer Contour_ mode