Coil cup

This object was composed in OpenScad to test the creation of a helical coil with an ellipse where the major axis of the ellipse is bent around the center to form an arc with a radius equal to the radius of the coil. With scaling common on all 3 axises any cross section of this coil perpendicular to the tangent of the helical function will reveal a circular profile, aka a rod.

Scale to desired size within your slicer. That is, unless you want a 2 liter container that does not actually hold fluid. :)