The Deepeeka stone grinder. Update and results of first try.

[Titus Petronicus Graccus]

Well Lugorix I tried just that and it works GREAT!
I finished the grooves today (I now have a newfound respect for stonemasons) and your right, it does operate differently in different directions. When the grooves are rotating against each other, it grinds very quickly and keeps pretty much everything inside. Then you change direction and it spits everything out the sides.
Once you get going, you turn it clockwise to get the wheat berries to be distributed evenly and then turn it anti-clockwise to grind them down. Lather, rinse, repeat.
Works like a charm!
Thanks for the suggestion. A laudes for you good sir!
Pedro

Does it help to mention that flat-surfaced querns were used differently than slope-faced ones? The flat ones would be better termed "oscillating querns", and the sloped-face type called "rotary querns." The difference in motion is shown on the wear marks on artifacts. Beehive querns are actually oscillating querns. They have pecked surfaces and lack grooves. To confuse the matter, Romano-British "flat querns" had sloped faces, and are rotary querns.

It might be worth experimenting by oscillating this grinder rather than rotating it. Curious what the reslts might be.