# Grinder RPM



## grumpydaddy (Oct 20, 2014)

There seem to be folks who have done all sorts of experimentation so I got to wondering...

Has anyone ever played around with the rotational speed of their grinder with a view to ascertaining if it has any effect on size distribution of the grind and, more to the point, whether there is any effect on taste ??

A number of the very large conicals use less rpm

It seems to me that the very large flat burr machines only run fast due to being designed to grind vast quantities.


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## jjprestidge (Oct 11, 2012)

grumpydaddy said:


> There seem to be folks who have done all sorts of experimentation so I got to wondering...
> 
> Has anyone ever played around with the rotational speed of their grinder with a view to ascertaining if it has any effect on size distribution of the grind and, more to the point, whether there is any effect on taste ??
> 
> ...


Our Anfims have flat burrs and run at 800 rpm, which is about half the speed of an SJ.

JP


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## 7493 (May 29, 2014)

Since most of the flat burr grinders rely on the rotation to throw the coffee out of the grinding chamber I wonder if decreased RPM would, in the absence of other design changes, increase retention.


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## Mrboots2u (May 10, 2013)

Rob666 said:


> Since most of the flat burr grinders rely on the rotation to throw the coffee out of the grinding chamber I wonder if decreased RPM would, in the absence of other design changes, increase retention.


Depends if the burrs are horizontal or not .

There was a slow spin Mythos for example but it has angled burrs

Think the mythos one is slow rpm also .


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## jjprestidge (Oct 11, 2012)

Mrboots2u said:


> Depends if the burrs are horizontal or not .
> 
> There was a slow spin Mythos for example but it has angled burrs
> 
> Think the mythos one is slow rpm also .


1400rpm.

JP


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## Mrboots2u (May 10, 2013)

jjprestidge said:


> 1400rpm.
> 
> JP


http://www.coffeeitalia.co.uk/proddetail.php?prod=Nuova_Simonelli_MYTHOS_BARISTA_Low_Speed

The older mythos has a slow spin variant of 400 Rpm

Why does the new take so long to grind if it's 1400 rpm


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## jjprestidge (Oct 11, 2012)

Mrboots2u said:


> http://www.coffeeitalia.co.uk/proddetail.php?prod=Nuova_Simonelli_MYTHOS_BARISTA_Low_Speed
> 
> The older mythos has a slow spin variant of 400 Rpm
> 
> Why does the new take so long to grind if it's 1400 rpm


Dunno. That was from the NS brochure - 2 speeds listed: 1400 and 1600.

JP


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## El carajillo (Mar 16, 2013)

The speed of the grind / output is greatly affected by the cut of the burrs, Ie depending on the aggressiveness of the teeth on the burrs.

eg. the Mazzer mini and S/J burrs are the same size 64 mm but S/J burrs cut / grind much faster, hence the reason people change mini burrs for S/J one's


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## jjprestidge (Oct 11, 2012)

El carajillo said:


> The speed of the grind / output is greatly affected by the cut of the burrs, Ie depending on the aggressiveness of the teeth on the burrs.
> 
> eg. the Mazzer mini and S/J burrs are the same size 64 mm but S/J burrs cut / grind much faster, hence the reason people change mini burrs for S/J one's


True. This and how the motor ramps up greatly affect grind quality. An SJ and a K30 have similar burr size and rpm but there is no comparison in grind quality.

JP


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## 7493 (May 29, 2014)

That was my thinking Martin, i.e. the Mythos could get away with lower speed due to the angled burrs. I've just looked on the Nuova Simonelli site and the Mythos One is quoted as having 75mm burrs at 900 RPM for the 220V version. the original Mythos also has the 75mm burrs but at 1400 RPM in the 220V version. The Eureka site only has details for the original Mythos. Just for fun here's a picture of one answer to the problem, the La Marzocco Disco Volante:


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## Mrboots2u (May 10, 2013)

Angled burrs were in part to help retention. The original mythos came in 2 models , one with a slow spin motor. Most in cafes were the higher rpm models as they probably wanted faster work flow


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## 7493 (May 29, 2014)

That would explain the enigmatic statement on the Nuova site about "two speed". This isn't mentioned in the user manual or the specs.


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## coffeechap (Apr 5, 2012)

jjprestidge said:


> Our Anfims have flat burrs and run at 800 rpm, which is about half the speed of an SJ.
> 
> JP


Similar to a royal though


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## jjprestidge (Oct 11, 2012)

coffeechap said:


> Similar to a royal though


Royal's burrs are bigger, though IIRC.

JP


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## charris (Feb 17, 2014)

Do flat grinders move at faster speeds than conical?


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