lino wrote:Huh. Interesting.
I'm assuming it's serial path, not parallel?
Is the path conical first, then flat? Though, wouldn't explain the beautiful exit vortex... Unless there were some "ducting" also.
Is it hard to take pictures of these? I find it very interesting!
ciao
lino
There's some pics in the copyrighted manual; I'll take my own in a few days.
The coffee bean goes through the conical pre-grinder, then the flat grinder. As in regular grinders, the upper burrs are fixed, screwed into the upper brass funnel, while the lower burrs are rotated by the axle. The flat burr is almost as wide as the lower brass funnel, and the grounds exit centrifugally and are thrown against the inside wall of the lower brass funnel, then they sheet down. There is a moving wiper that cleans off the sides of the brass funnel, rotated by the same axle, and a fixed wiper that cleans off the underside of the lowest burr mount as it rotates.
One of the keys here is that there is no grounds chamber and exit tunnel -- the grounds go directly from the outer perimeter of the flat burr to the brass funnel. This eliminates the 5 to 10 grams of stale coffee that always gets compacted inside conventional grind chambers. It also means the coffee distributes beautifully and without clumps.
Versalab is basically a very small shop; but this exit system is something the main grinder manufacturers should look into. The distribution in the basket is so good that Andy and I have been frustrated doing blind shots due to the better pours from the M3 shots. The initial flow is always close to perfect (as Abe noted), whereas it's hard to avoid the initial uneven appearance of coffee-blobs from a conventionally ground shot.