I am not sure about the reverse rotation. But from a practical standpoint, if dual burr was a better grinder then it should be possible to demonstrate the benefit using two separate grinders. First grind one coarse for the crusher and then grind in small doses into the second grinder. This would be very inconvenient but I would think the benefit should be demonstrated.

The product description says the filter screens are removable, don't have to use them. 400 micron is much too large and anything smaller requires vigorous shaking to produce the result. Maybe they should just dump the new grinder altogether and just sell the filter screen shaker appliance for use with any other grinder.

Actually, Kafatek's description of the MC4 is the following: "Monolith Conical (MC4) is completely original design, first dual-conical burr espresso grinder in the world." Also, if you use the Auto-Translate on the video posted earlier, at 3:16 the reviewer says specifically the intent is to break up the beans before hitting the more refined burr set below--not as a separate burr set. I'm not saying this grinder will be great, but it is interesting to see the technology advancing like this. If they get it right, it could be a step forward for manual grinders. I agree, as does the reviewer, that I don't like the reverse rotation.

Surely the question of whether two stage grinding has merit has been fleshed out already? No?

INAB says the grind direction is for better ergonomics but also to give lefties a chance. Well, which is it? It can't be both.

I mean. I'd guess it's because they can't get reverse burrs, c.f. the Knob. Although the Knob had the misfortune to launch their crowdfunding campaign while still believing they could talk a burr manufacturer into making reverse burrs, then had to revise halfway through when it turned out there was no way that was going to happen. A fair amount of conversation about reverse grinding on this forum ensued.

As far as two stage grinding, there's been discussion on this forum about that as well. People were doing it manually before the MC4, but as far as I know Dennis was the first to build a grinder around it. Pretty certain he wouldn't have done it unless there was an advantage.

It was done by the Versalab at least 12 years ago and by DRM before that which is the machine those burrs came from and in another machine who's name ended in "Jr." about 9 years ago, great grind quality, lots of retention.

Ira

There is one monumental difference between them, the Wontung version can as far as I can tell only adjust the lower burr from the bottom, the Momemtum improves on this by adjusting both burrs externally.

The Wontung adjust by 29micron I cannot tell how much the momentem is because they don't provide the info. But it's equal to that of the Comandante and double that of red clix and 6x that of many new espresso hand grinder

Did he just use lighter fluid to stop the squeak? at the end of the video? I'm guessing food safe lubricant or oil would also work? :p
Not sure I understand the reason behind the reverse rotation?

Like I said, it could change the game:

It's available on Indiegogo now: https://www.indiegogo.com/projects/mome ... grinder/#/ I didn't bite as I already have a hand grinder and the price seems too high for me for this one, but it seems like they corrected some of the issues previously discussed, notably the way the grinder rotates. It will be interesting to see if anyone buys this and reviews it here.