I just re-read this entire thread for some reason. Anyway, Spiral you had posted about a 6" grinder and then max had said Kelly advertised the largest as a 4". He DOES in fact sell the 6", and the picture you posted was from KGP. This is the link to that grinder:
http://cgi.ebay.com/FULLY-CNCd-150m...096230199QQihZ019QQcategoryZ133QQcmdZViewItem
It is the 150mm fully CNC'd grinder...so at 150mm it's not QUITE 6 inches, but damned close
(about 5.9 inches, if it is in fact 150mm). About this one he says "This is by far the largest grinder on eBay". I don't know...6 inches is definitely the largest one I've seen to date. Maybe he just screwed up on the 4" page? I didn't try to find the grinder you're talking about max, so I don't know if it does in fact claim to be the largest grinder on ebay there as well.
max, I have a question for you regarding KGP. You said that your cheapie grinder (which I presume is one from him??) leaves the same aluminum residue on your fingers as my MM? You also implied that this might mean it's constructed of lesser quality aluminum? Is this correct (that implication, I mean), or did I misconstrue something? Also, which grinder of Kelly's does leave the residue? Is it only the cheaper aluminum grinders, or does your more expensive "Fully CNC'd" grinder also leave that residue? I would really like to know, as I don't really trust something which will leave a metal residue on my fingers simply from gripping it...
Acolyte, I think your looking at the wrong grinder. The 1 3/4" grinder with 3mm holes is this one, I believe:
http://cgi.ebay.com/1-3-4-Prime-Qua...216998691QQihZ020QQcategoryZ133QQcmdZViewItem
Correct me if I'm wrong, max. While I'm at it, the 2.5" grinder which allows you to select the hole size is found here:
http://cgi.ebay.com/NEW-STYLE-2-5-S...028498243QQihZ019QQcategoryZ133QQcmdZViewItem
It is called the "New Style 2.5" Spaceage Aluminum Herb Pollen Grinder". Regarding your query though AoZ, I have often "pre-ground" large quantities of bud and find that as long as it is stored in glass and is kept relatively air tight, it doesn't cause a loss of anything...taste, potency, what have you. I always use glass because it is so easy to collect trichomes from glass...nothing gets stuck or becomes wasted.
I don't know though...this whole question is probably pretty open for debate. Obviously your bud could get dried out a lot quicker with more surface area exposed, so it's pretty important to keep it properly stored after it's ground. Decarboxylation is again something to consider...I dunno. At the moment, I don't tend to do big grinds. I'm basically grinding bowl to bowl. The freshness is nice, but I vape too much for this shit...I need to go back to grinding and storing. Actually, even when I smoked I was pre-grinding and carrying chopped herb around with me in a little tin, and that was very far from airtight...it didn't seem to be too adversely affected. I do tend to blow through herb pretty quickly though...so it doesn't exactly sit around for ages getting exposed.
Oh and AoZ, just to be clear...the Scout style grinders found at KDP don't keep ground bud in the bottom part of the grinder: at least, it doesn't auto-collect there. There are no holes in the grinder itself. Rather, it is a 1.25" grinder that is simply a two piece grinder, the bottom of this however screws on to the top of the long, bottom canister. This makes the scout grinder effectively a stash jar with a grinder for a lid. Kid of a neat idea, actually. So, although you could fill it with pre-ground herb, that does not seem to be the intention.