I have been wanting a funnel that could handle denser solutions. After a few variations this has been the simplest I have came up with. The adapter is a 4' x 3". The center piece is a snap in 3" plastic drain from Oatey, the same people who make PVC cement. The four inch fitting is a nice fit for coffee filters and does pretty good with the heavier commercial tea filters.
Edit to correct the size adapter needed.
Edit to correct the size adapter needed.