Is this crazy? An EK style hand grinder?

Grinders are one of the keys to exceptional espresso. Discuss them here.
Prescott CR
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Postby Prescott CR » Apr 15, 2018, 11:13 pm

I was just thinking - with the auger system in the EK, could the motor be replaced with a hand grinding system? In my head I really like the grind-through way of grinding for (virtually) no retention, but the EK is a little big. If the motor could be replaced with a flywheel (if necessary) and a handle like the HG maybe it could be a still sizable but serviceable hand grinder. There may need to be a smaller gear turning the main driveshaft to make it work properly.

This set up with a guitar tuner style grind adjustment at the top of the front dial would be pretty cool.

This would be a single doser / home grinder option of course.

Perhaps someone has done this already and I'm not aware, maybe the SSP guys would kick the butt of a project like this...
-Richard

erik82
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Postby erik82 » Apr 16, 2018, 3:04 am

Flat burrs need a minimum of 300-400rpm which makes it completely impossible to build as a handgrinder. Humans aren't capable of reaching that speeds.

cebseb
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Postby cebseb » replying to erik82 » Apr 16, 2018, 5:36 am

Not with that attitude.

Seriously though. I have a difficult enough time getting my Pharos started on some single origins. I can't imagine the amount of gearing required for 98mm flat burrs to be hand cranked.
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aecletec
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Postby aecletec » Apr 16, 2018, 6:14 am

A flat burr by itself might not work, but a drm-like arrangment such as how Spong burrs were shaped or this interesting piece might work...

erik82
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Postby erik82 » Apr 16, 2018, 6:21 am

cebseb wrote:Not with that attitude.

Seriously though. I have a difficult enough time getting my Pharos started on some single origins. I can't imagine the amount of gearing required for 98mm flat burrs to be hand cranked.


It's not the first time someone came up with this idea. Conical burrs are well suited for handgrinders but flat burrs aren't. There's no arguing with the laws of physics. Setting a minimum requirement of 5 years use of steroids and a minimum of benchpressing 300Lbs to be able to operate such a handgrinder won't be a very good selling point :mrgreen: .

Humans just aren't made to do such tasks. The minimum rpm will never be met for these types of grinders and using gears will only make the problem worse as you have to make even more rpm's on the flywheel. Humans just aren't capable of doing that so it's not my attitude that's the problem here :wink: .

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AssafL
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Postby AssafL » Apr 16, 2018, 6:45 am

Cyclists during TT do about 90 RPM on their pedals. Fitting a 5:1 gear ratio makes it 450 RPM which can be used to grind the coffee.

I don't know if using feet counts as a hand grinder. Maybe it should be called a foot grinder?

Since a male (humans, other animals - like oxen - may be different) produces between 200-500W small burrs would work well. Larger burrs you'd want to pour light roasted beans in slowly. Or kidnap a competitive cyclist and feed them cereals and steroids. A la Les triplettes de Belleville.
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Unrooted
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Postby Unrooted » Apr 16, 2018, 10:38 am

Any opinions on the new Apex hand grinder from Orphan? It uses a flat ghost burr. . .

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hankua
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Postby hankua » replying to Unrooted » Apr 16, 2018, 10:56 am

A working prototype is supposed to be on display at the upcoming Coffee Expo in Seattle.

Prescott CR
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Postby Prescott CR » Apr 16, 2018, 11:35 am

aecletec wrote:A flat burr by itself might not work, but a drm-like arrangment such as how Spong burrs were shaped or this interesting piece might work...


That's a pretty different looking burr set!

I was thinking the auger system of feeding the burrs could be used to limit the amount of coffee entering the actual burr set to a manageable amount.

Still, it's the kind of thing that would be done already if it could be done, no doubt.
-Richard

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AssafL
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Postby AssafL » Apr 16, 2018, 12:11 pm

If it is mounted vertical does it still need the 450RPM?
Caution! Water, heat, pressure and electricity don't mix! I want an espresso.