Hi guys,

Cecil - that SSR was simply something I got from a friend for free. He had quite a lot of those laying around and so sent me one to use for the grinder (thanks again Eric!). From what I remember the HD4850 can handle way more then the grinder motor so I'd say it's way over the top, but I don't really care. Better to have too much than too little:)

John - to be honest I've not had problems with static for quite a while. Not sure why, but I'm not worried:) I was thinking of adding an ion generator, but I'm a bit worried that it may affect the electronics, so I'll live without it for now.

Regards,
dsc.

Yeah, static seems to be affected by the humidity and the coffee far more than anything I've tried, at least. My static has actually got much better since yesterday strangely- but that's probably because the RH is higher today (there is something to be said for cloudy weather).

I can't come up with an argument for how the coffee particles would pick up or give up charge along the grind path if they are neutral after being broken.

Try googling the triboelectric effect. Air is at the top of the triboelectric series, wood (which I guess is similar to coffee) is slightly south of the middle. The coffee will therefore pick up a negative charge and leave the air slightly positive as it flies out of the burrs.

-John (still trying to pull two good shots in a row...)

jcj wrote:
...
Try googling the triboelectric effect.
...

John,
Thanks for the tip. Had not heard of this term before, although it seems
to be responsible for the familiar static build up when rubbing objects together.
I failed to consider the air "rubbing" the coffee grinds when I thought about
the problem before. I am interested in finding a more quantitative analysis than
what I have seen thus far. I'm wondering what order of magnitude we are talking
about here, regarding charge transfer with the air. This certainly does seem to be
a possible explanation for the charge build up.

Best,
Jordan