Lower burr carrier design for reduced clumping - Page 2

Grinders are one of the keys to exceptional espresso. Discuss them here.
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civ (original poster)

#11: Post by civ (original poster) »

Hello again:

Once again, thanks for the input.
shadowfax wrote: This is part of the trick of the Nino: There is no horizontal "part of the path."
Ahhh ...
No horizontal path at all means that whether it is pushed or thrown out, it practically falls where it's intended to go: into a vertical/inclined chute or a doser. Interesting.
shadowfax wrote: Trying to engineer a better throw is, IMO, not going to work ...
You may be right.
I agree that static and the inherent fluffiness of the grind (ie: low specific mass of the particles) will conspire against an optimum result as will the addition of wires to try to cancel static. But I have the idea that, given a specific rig such as the one described in my OP, a new lower carrier with the addition of more vanes will improve the situation and if some sort of bean flow control (ie: not all the beans at once) can be put in place, the whole process may be optimised significantly. Certainly, it won't be a Nino but then it won't cost me what a Nino costs. =-)

Nino's vanes are indeed of a very interesting design and I agree that they probably contribute a lot to the performance of the grinder, but it's main strength is, IMO, the null horizontal path.
shadowfax wrote: ... the burr is mounted lower in the carrier so that the fins rise to meet the ring where the coffee comes out of the burrs ...
I expect to be able to mount the lower burr (height = 10 mm.) as low as possible, so that the ring where the ground coffee comes out (meeting point between the two burrs) is about 13.5 mm from the bottom of the grinding chamber. The vanes would reach up about 5 mm past this point and catch all the ground coffee that is dropping into the chamber.
shadowfax wrote: Anyway, I will say good luck to you--I'll be interested to see what you finally come up with for a design. I hope I've made my concerns a little clearer as well, or at least given you links some more discussion in other threads--they have very detailed photos, and are great reads for what you're looking into.
Thanks a lot for the good luck and your constructive input.
I really appreciate it.

Best regards,

CIV

IMAWriter

#12: Post by IMAWriter »

Carlos, a most interesting discussion. Thanks for kicking it off.
Rob
LMWDP #187
www.robertjason.com

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civ (original poster)

#13: Post by civ (original poster) »

Hello again:
another_jim wrote: ... there's probably a good deal that can be improved in the conventional layout.
Yes, I think so too.
And not only in the lower carrier field. With respect to flat burr grinders, I have seen quite e few (mostly on the web) but surely not all there is to see. In any case, the vast majority are vertical designs with one or two (?) horizontal designs. As another_jim has pointed out here and in another thread, these last ones are mostly bulk/bag and not espresso type grinders.

Now, thinking out loud: why are 'vertical' and 'horizontal' the only possible options?
I know there are a lot of reasons which go from manufacturing costs to Mrs. Espresso Lover's convenience in her kitchen.

But gravity is always present, why can't it be used to feed the grinder and to help the grounds come out without problems?
shadowfax wrote: ... I'll be interested to see what you finally come up with for a design.
No ground-breaking research here ... 8^D !
This is a very (very) rough approximation to how this lower carrier would eventually look like.
The upper burr is shown only in the cross-section to show the approximate height of the vanes.

Image
CAD courtesy of Alexandre Grabois

The grinding chamber is 95.0 mm. in diametre, the bottom part of the carrier (where the vanes are placed) is a platform 3.0 mm high, 7.45 mm. wide and ~ 94.0 mm. in diametre with a minimum clearance over the bottom of the grinding chamber. The vanes are ~ 7.45 mm. x ~ 2.0 mm., higher than the the contact point between the two burrs by ~ 5.0 mm. and a minimum clearance between the vanes and the inside perimeter of the chamber. The vanes are placed in a radial (not slanted) pattern, something that will have to wait while I think of a way to hold them firmly in place without any welding or soldering.

Tests I made with a temporary carrier verified that at 1450 rpm, if it hovers with a minimum space above the bottom of the grinding chamber, practically no grounds are retained there and that a clearance of up to 1.5 mm. between it's the vanes (3) and the inside perimeter of the chamber will keep it surprisingly clean.

Of course, the problem solved by Elektra with their intelligent Nino design is still present. 8 ^/
Randy G. wrote: Trying to use centrifugal force to move the particles horizontally as they are packed into a chute is problematic.
To say the least.
IMAWriter wrote: Carlos, a most interesting discussion. Thanks for kicking it off.
Thank you very much, very kind of you to say so.

Best regards,

CIV

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another_jim
Team HB

#14: Post by another_jim »

Off Topic:
shadowfax wrote::lol: Right. Because the Compak K10 dosered grinder isn't already much more than half the price of a Nino...
In the past, and still now, I make fun of doserless grinders where they just remove the doser, add a spout and timer, and then charge two hundred bucks more. I do it because I have a hard time believing that even the manufacturers think it'll work. I don't make fun of the Nino (or the Mahlkoenigs, the Swift or the NS Mythos) because these are serious portioning grinders, designed for the job from the ground up. They may not work perfectly, but they are for real, and each new design is slightly better than the previous one. The E series from Mazzer, on the other hand, deserves all the mockery I can heap on it, and a lot more (A freebie: what part of putting a propeller beanie on a grinder don't prospective buyers get)
Jim Schulman

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dsc

#15: Post by dsc »

Hi guys,
where they just remove the doser, add a spout and timer, and then charge two hundred bucks more.
if only, last time I checked a normal dosered Robur was 2300$ and the E version was 3400$. A bit expensive to say the least.

Regards,
dsc.

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civ (original poster)

#16: Post by civ (original poster) »

Hello again:

Please excuse me quoting my own post .... 8^/
civ wrote: ... why are 'vertical' and 'horizontal' the only possible options?
I know there are a lot of reasons which go from manufacturing costs to Mrs. Espresso Lover's convenience ...
But gravity is always present, why can't it be used to feed the grinder and to help the grounds come out without problems?
This is what I meant:


CAD courtesy of Alexandre Grabois

With an efficient lower carrier design to leave no stray grounds inside the grinding chamber, a grinder inclined at 45° to 60° from its longitudinal/vertical axis would take advantage of gravity to on one hand smoothly feed beans into the grinder's throat without the need of a worm (as in horizontal designs) and on the other, help ground coffee move down from the grinding chamber exit by using a some sort of toboggan or chute, ie: like the Nino design uses.

Of course, this is still all about an 'on-demand' grinder for low per grind volumes.

Any comments will be welcome.

Thanks in advance,

CIV

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shadowfax

#17: Post by shadowfax »

That's been done by Nuova Simonelli... Looks like it has its own set of issues.


The Nuova Simonelli Mythos Espresso Grinder (Flickr link).
Nicholas Lundgaard

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Psyd

#18: Post by Psyd »

shadowfax wrote:That's been done by Nuova Simonelli... Looks like it has its own set of issues.
Krups did it a while ago with their Caffina burr grinder. Stepless, clumpless, and almost no retention. Sure, it wasn't the best thing you can get your hands on, but it was a flat burr grinder, and basically worked like a cheaper hand-grinder with a motor attached-ish.

Here's an artist's rendition of how the motor and burrs were mounted in the plastic body and the burr exit.

Espresso Sniper
One Shot, One Kill

LMWDP #175

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civ (original poster)

#19: Post by civ (original poster) »

Hello again:
shadowfax wrote: That's been done by Nuova Simonelli... Looks like it has its own set of issues.
Psyd wrote: Krups did it a while ago with their Caffina burr grinder. Stepless, clumpless, and almost no retention ...
Thanks for the comments and the photos.
Certainly hope I haven't come across as having invented the wheel ... 8^o !
My idea is only about finding a way to make an old 'standard issue' large, flat burr espresso grinder behave/work better than it does (for our single 14 g. serving use) by modifying what may be relatively easy to modify.

I had not seen these two examples so I'm evidently not looking at enough grinders, but from what I have seen/read recently, it would seem that a lower carrier with better design on an inclined axis + a toboggan / chute could well be the better part of the solution to grinding chamber retention issue.

The other issue (clumping / static) may be, in the absence of doser vanes to tend to the problem, something to be dealt with in the same manner, ie: once the grounds are out of the chamber and on their way down to the portafilter.

A flour sifter/shaker comes to mind at this time.

I'll try to get the metal shop/lathe schedule ironed out and post any significant advance I make.
Thanks a lot to all for the input.

Best regards,

CIV

Gime2much

#20: Post by Gime2much »

On the cheap; why not clamp a 45 degree wedge to the bottom of a grinder and check the results? Wouldn't that be the same thing?