Customizable funnel with adjustable parameters
The real point of interest is the OPENscad, but I've included some examples of what I've made as well.
All of the prominent features can be seen in the photo of the finished print and are each customizable. With the tab being an optional addition. The diameter and height of the three body sections of the funnel can be changed to meet whatever is needed. Resolution can be changed to allow for airflow if you plan on pouring into round holes.