I made a simple funnel in openscad a few months ago & needed to change it & decided to make it more customizable. I looked at a few images of funnels on the internet to get an idea of what else to vary in the design & this is what I came up with.
Since there are quite a few variables you can change, I added a screen shot of a drawing showing what each dimension is related to. The Small_Thk dimension is only changable in the downloaded openscad source. I made it the same as Thk for the thingiverse customizable version. I included a STL file of the size I used & this is also the default settings in the openscad script.
I changed the Hook_xx variable names to a more appropriate Eye_xx names after a friend mentioned this.