I did my first drip grind today and I must say that static was a very serious problem! Yikes coffee everywhere. I wound up having to leave my lid on and also cap the bottle. After grinding the whole inside of the bottle was covered. I removed the lid and brushed the coffee down to the bottom. Removed the bottle cap and emptied the grounds into the lid from my coffee jar (then into my drip filter basket). I wonder if a sleeve of aluminum foil would buffer the static issue?
When I originally did my mod, (shown in the post immediately above), I thought that I had somehow managed to avoid the static issue. However as the weather got warmer and drier I realized that I did have a static problem
, though not as profound as what you describe. With my mod the ground coffee did not seem to have much of an affinity for the ABS couplers that made up the mod, but rather as soon as the grounds were dispensed into a non-conductive container, I could tell that it was charged quite a bit. When I would spoon out a measure of grounds from the container, (with a non-conductive scoop), some of the disturbed grounds would get dislodged from its neighbors and jump to the other side of the bowl.
The first thing I did was to use a metallic bowl to collect the grounds
. That didn't completely solve it, as there was still much residual charge left in the grounds that didn't make contact with the container. What was needed was a means by which the grounds, during its free fall to the waiting container, would touch a grounded surface.
What I ended up doing was to fashion a sheet of copper foil into a cone
, as tall as the stackup of the two ABS couplers used in my mod. This copper cone would then line the inside of the ABS couplers
, and as it fell it would encounter the narrow portion of the cone, increasing the likelihood of contact with the copper. It also had the benefit of presenting a smooth surface to the falling grounds, vs. the steps and ridges present in the ABS couplers themselves.
Perhaps copper foil isn't quite the right word, as the copper I used was substantially thicker than household aluminum foil. It's easy to work with and doesn't "crinkle up" like foil does, and it takes on a relatively strong and permanent crease when you want it to.
Where the rectangular exit hole from the grind chamber would be, I cut into the copper foil an "X" of equivalent height and width. This created four triangular tabs which I bent through and back a similarly shaped hole in the top ABS coupler. Though it is making superficial contact via these tabs to the grinder body, the main grounding is occurring with the 2 screws
(that used to attach the doser to the grinder) that is now used to attach the top ABS coupler to the grinder body, and
in the process also clamps down the copper foil completing the ground
I have been using this mod for over a year now and no longer have a static issue
. As you will see in my "workflow" video (also linked in the above post) I no longer scoop out the grounds from the container either, but rather dump the entire contents into my portafilter via the use of a wide-brimmed funnel.