No-Mess Dosing and WDT Funnel for 58mm Baskets

A funnel with a small lip that wraps around the edge of 58mm baskets to help prevent grounds from getting trapped between the funnel and the basket during aggressive WDT, and eventually ending up on your counter. The lip is small enough that the basket can be tamped with the funnel on.

The cutouts are designed to fit the lugs of a Gaggia Classic portafilter, but will probably fit most 58mm portafilters.

The funnel has been tested and works well with IMS and VST 58mm baskets, but it may be compatible with others.

Food Safety

Printing a part from food safe plastic does not make it food safe! The surface of FDM 3D prints traps bacteria and is usually not water-tight, even if it looks like it is.

Because the funnel is in regular contact with coffee, it should be coated with an epoxy specifically approved for food contact. The funnel in the pictures is coated with MAX CLR which is formulated for direct food contact in accordance with FDA regulations. Always follow all manufacturer curing and use guidelines to ensure the finish is food safe. Be sure to wash the part with warm soapy water after the epoxy cures before using.

Printing Recommendations

I was able to print this in PETG on a Prusa  powder coated satin PEI sheet with the top of the funnel facing down without a brim or supports. A brim may be necessary if you have adhesion issues.

I recommend using variable layer height and reducing layer height  around the basket lip so it matches the designed profile as closely as possible, though I have had success printing at 0.2mm layer height as well. Epoxy will help smooth things out either way.