Knob Coffee Grinder (Kickstarter) - Page 8

Grinders are one of the keys to exceptional espresso. Discuss them here.

#71: Post by canatto »

I counted 117 crank revolutions in the video for 20g espresso. That's almost too many turns, even for a travel grinder.

The information disclosed so far tells very little if nothing at all about the bearing and the support system in the grinder.

The Knob grinder has, as its creator claims, only two major components, an inner cylinder and an outer cylinder. The inner cylinder carries the outer burr, and the outer cylinder the inner burrs. By allowing these two components to revolve against each other while maintaining a minimal or no free play in between, a precise and consistent concentric burr-set positioning during the grinding action is therefore achieved. We need a bearing system in between the two major components to do that job.

In a manual machine like the Knob grinder we would expect the bearing system to
1. be of no free play
2. bear the radial loading, a loading that could be substantial when the muscle drive isn't perfectly circular
3. maintain the coaxial positioning between the two cylinders even under radial loading, this often calls for a double-row bearing or alike
4. bear the axial (thrust) loading
5. allow clean and easy separation of the inner and outer cylinders

It would have been a lot more convincing if they had demonstrated how the bearing and the support system is constructed to do all the above.


#72: Post by CathyWeeks »

LewBK wrote:Pretty funny article about this grinder mentioning its problematic branding in the UK: ... -grinding/
Eh, I think I'd just go with the original name or change it entirely. My impression of the Brits I've known, is that they are no prudes, and so why not take advantage of the notoriety? Nothing like a penis joke to gain name recognition. And why add confusion - the restaurant chain Panera used to be called St. Louis Bread Company. It's still called St. Louis Bread company in St. Louis, Missouri, but Panera everywhere else, but it's the same restaurant and chain.

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#73: Post by Pressino »

Yeah, nothing like cranking your Knob to prepare that first morning coffee.... :twisted: