Looks nice Jim!

Despite having a so-called infinite adjustment, the Mini's espresso grind range is a rather narrow band. So I have a question for our test panel: How does the granularity of the M3's adjustment compare to a Mazzer's?

What burr set does the M3 use? Do I remember hearing that it is an existing set. (not made by or for Versalab)

ciao

lino

HB wrote:Despite having a so-called infinite adjustment, the Mini's espresso grind range is a rather narrow band. So I have a question for our test panel: How does the granularity of the M3's adjustment compare to a Mazzer's?

Mazzer's burr carrier thread pitch is 1.5 mm. M3's is 0.79 mm.

So the M3's adjustment range is "stretched out" compared with that of the Mazzer.

lino wrote:What burr set does the M3 use? Do I remember hearing that it is an existing set. (not made by or for Versalab)

The M3 uses a flat set and a conical set (4 pieces in all). The flat set is sourced from Italy, the conical set is out of production and had to be reproduced in the US.

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

lino wrote: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.

It is serial: conical then flat. I just finished disassembling it and will post picture on my Day 3 report. The vortex is created by a combination of the spinning burrs and a wiper that is extended from the lower burr into the chute. As the wiper spins with the burr, it aids in creating the vortex. The original purpose of the wiper was to clean the chute walls from grounds, and my feeling is that they discovered its real benefit as an afterthought.

Is it hard to take pictures of these? I find it very interesting!

I took that picture using a digital camera on high shutter speed. It is not difficult really, if you know what you're doing .

AndyS wrote: I'm looking forward to hearing your results. Keep those great photos coming! It's a sweet little grinder, isn't it?

It is a sweet little devil indeed. I'm almost done with my Day 3 report which I will post later on. Andy, do you have a static wiper on your lower burr. Look at the user manual, mine is totally missing.

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.

another_jim wrote:Hi Abe, my congrats on the awesome pic of the grounds exiting the grinder.

Thanks, Jim. I can't wait to hear your blind test results. I intend to do mine towards the end of the week. This is getting really exciting

Day 3

Today is maintenance Day. I took the grinder apart to understand how it does what it does, and to see how difficult it is to maintain. Let's take a look.


The funnel - extreme closeup

First to be removed is the funnel. The grounds exit the grinder from here in a vortex, a little Tornado. That view of the funnel reveals how the vortex is created. The spinning bottom flat burr throws the grounds out in centrifugal pattern. However, what gives them an extra spin and greatly enhances the vortex is the wiper. It is attached to the bottom burr (the spinning burrs are the bottom ones) and spins with it. The official job description of the wiper is to clear the inside funnel walls from any leftover grounds. But it doubles also as a little tornado engine, and is equally responsible for the M3's even distribution. As Jim mentioned, the elimination of an intermediary tunnel between the grinding burrs and the grounds exit is at the heart of The M3's exceptional performance.



The funnel removed

The conical plate is holding the bottom flat burr. The M3 has two sets of burrs, one conical and one flat. the order is serial: The beans are first ground by the conical burrs, and then move to the flat burrs to finish the job. There should also be a static wiper wiping that conical plate as it spins. My machine does not have it.


Bottom conical burr


Bottom flat burr


Flat and conical burrs side by side - Red Possum sold separately


Top burrs

Disassembling and cleaning requires more caution than The Mazzer, but it is easy enough. The hard part is reassembling the wiper. It has to be very close to the funnel wall but not touching it. There is wiggle room for adjustment and it took me a while to find the sweet spot again.

Tomorrow will be dedicated to determining the best Barista technique for the M3.