Are there flat manual grinders? - Page 2

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

#11: Post by baldheadracing »

RedPanda wrote:But the design of having a vertical mount solves that problem... so *shrugs*
Unfortunately, it doesn't solve feed rate, assuming currently-available commercial burrsets.
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

ira
Team HB

#12: Post by ira »

Yes, if you've ever used an Apex you will likely understand the issues of feeding a flat burr. I'd guess since the comical shape is better in essentially all ways for hand grinders, that there's not ben much effort put into making hand grinders with flat burrs. OE only made the Apex because Doug wanted a hand cranked ghost burr grinder and as a grinder for brewed coffee, it's hard to better, but it's pretty obvious those burrs were not designed for a hand grinder. I have a spare set of Apex burrs that one of these days I'm going to try modifying to see if I can make them feed better.

sochaux_

#13: Post by sochaux_ »

@RedPanda There are some custom made flat burr hand grinders. Search about Bonafabrica. For example this thread/post: Custom grinder Bonafabrica from Russia

RedPanda (original poster)

#14: Post by RedPanda (original poster) » replying to sochaux_ »

sadly most of us cant buy from Russia. Maybe someone China or Taiwan can.... but everyone else nope.


His FG98 grinder looks awesome and simple and super compact.... but sadly we cant try it out :cry:

Pressino

#15: Post by Pressino »

The Russian hand grinder looks very nice and well-made. Because it uses typical modern flat burrs (64mm), I suspect there may be some difficulty with bean feed-through while grinding at normal hand crank speeds, especially for the finer grinds. The Apex's ghost burrs are designed to allow easier bean feed-through with hand cranking, but its design also limits its ability to grind in the espresso range. Feed through is less of an issue for motorized flat burr grinders that employ modern flat burr sets.

ira
Team HB

#16: Post by ira »

I don't know why you think the Apex burrs are designed for hand grinding, they're ghost burrs in a hand grinder and they certainly don't feel like they were redesigned for better feeding. And while it sounds like you somehow expected it to be able to grind for espresso, it was stated from long before it was released that it was for pour over only and some are of the opinion it won't get fine enough all pour overs methods.

BodieZoffa

#17: Post by BodieZoffa »

ira wrote:My Spong, while mostly flat, certainly feeds like a conical. If you think about conical burrs, they will in general happily feed beans at speeds approaching zero RPM while most flats won't. So far, all flat burrs seem to have been designed to be force fed, either by beans being thrown into the burrs by spinning fast, fed with an auger or both. In contrast, most conical burrs start with what might be considered a built in pre-breaker, making it easier to get the bean into the actual burrs. A flat burr designed to be more aggressive at grabbing beans or with the addition of a pre-breaker might work fine as burrs for a hand grinder, but the diameter might have to increase significantly. But you'd have to put up with a grinder with a much larger OD, no flat burr travel grinders.

In theory, any burr should be able to be made in any shape. Flat burrs can in theory be made on much less expensive equipment than a conical and are a lot easier to design, though modern design tools may make translating a design between the two much easier.

And as a positive sign for the future of small conical burrs, I'd guess from the number of seemingly different styles appearing recently, that someone is making them on a CNC mill and trying to improve on what we have today.
I'd also question (likely) retention in a flat/manual use as the beauty of conicals is a gravity fed/straight thru approach so little is ever left behind...

Pressino

#18: Post by Pressino »

ira wrote:I don't know why you think the Apex burrs are designed for hand grinding, they're ghost burrs in a hand grinder and they certainly don't feel like they were redesigned for better feeding. And while it sounds like you somehow expected it to be able to grind for espresso, it was stated from long before it was released that it was for pour over only and some are of the opinion it won't get fine enough all pour overs methods.
The ghost burr design was used in the old hand cranked grain grinders, which were quite large by today's standards. They were designed that way to allow a flat burr grinder with burrs held more or less vertically to allow for smooth feeding of grains, like wheat and dried corn. Due to their having grinding nubs, the fineness of grind was less than what you could get from conical burrs back in their day.

I didn't think that ghost burrs were designed for hand grinding in the Apex, rather that OE used them in the Apex because they would feed better in a hand grinder than would flat burrs of modern design, which is clearly true...and was my point about the Russian hand grinder cited above.

I didn't expect the Apex to grind fine enough for espresso...because, as I pointed out, ghost burrs, at least as currently designed and manufactured, can't do so. :)

ira
Team HB

#19: Post by ira »

The Apex has ghost burrs because that's what Doug wanted, he never considered more normal burrs.

Jonk

#20: Post by Jonk »

There are old examples of conical hybrid ghost burr grinders like this one: https://www.old-coffee-grinders.com/son ... 1910-1920/

I wonder how it'd behave in comparison :)

And there are more old examples of flat burr hand grinders like:

(Husqvarna no5)

and hybrid conical/"flat":

(Husqvarna no4)