A funnel to fit gallon water bottles.

I made this funnel to transfer filtered drinking water from a 5 gallon bottle to several one gallon bottles. 5 gallon bottles start off heavy, and difficult to aim.

Early attempts had no curved lip. If water hit the side it sloshed up and out. The curve does an excellent job of preventing that. It speeds things up and makes the job easy.

(I'd bet the main reason this curve is absent on cheap commercial funnels is it makes the mold far more complex and expensive. Also harder to stack and ship them. 3D printers are wonderful things...)

The base ring rests on the lip of the bottle and is notched for air exit, so there's no air-lock.

Overall dimensions are roughly 4"x4" (100mmx100mm). The tube is 1.2 inch diameter (30mm) and fits disposable, store-bought 1 gal water bottles.

Scaling larger or smaller seems doable, up to where the walls become impractically thick or thin.

Afinia defaults except for 0.35mm layers to save some time.
110 minutes, 57 grams ABS.
There was no support to speak of when STLs were printed as posted.
[NOTE] If printed on an Afinia, which automatically adds support under any overhangs, be aware there is a microscopic edge, inside, where the curved lip is attached to the body.
Around layer 20 or so, my printer started printing some wild hairs, so I STOP the print. I thought it was a bad design or something, and a failed print. But the few random strings of filament was just support for that virtually invisible edge. So, let the print continue if you see it happening.]

A metric version is included.