I love funnels. They are so fun, it is right in the name. Big funnels for pouring stuff into a big gallon jug, to a small funnels for small little bottles. Without funnels the world is a messier place. Why should I have all the fun? I made an openscad for making funnels. Just four variables; large end the wide part of the funnel, small end, the narrow part of the funnel, the neck length , how long is that small part and the wall thickness. I hope you enjoy making funnels as much as I do.