Parametric Funnel - I needed one around the house, so put this together in an evening.
Make sure to print with a brim. The surface area of the base is otherwise very small and can come unstuck from the print bed. I printed at 0.25 layer heights in PLA and it's watertight. I think that's helped by the wall thickness not being a whole number of nozzle widths.
Model is designed in OpenSCAD for people to edit and improve themselves.