As I mentionned it in the post, I didn't design the funnel. I could have, but this one is already perfect.

Also, I have printed it at a public library, it costed me less than five bucks. More and more publics librairies have 3d printers and other manufacturing machines. I like the idea of community owned equipment. I know that not all public librairies have those, but I think that people that can find a 3d printer and learn a thing or two about design could do a lot.