Tiny motors on new grinders? - Page 6

#51: Post by **buckersss** » October 24th, 2021, 10:09 am

coffeeOnTheBrain wrote:Thanks to all if you for the great read. And please excuse my lengthy post

There are many different kinds of motors out there with very different characteristics. A 200w AC motor is very different to a 200w DC motor. The 200w are only the peak wattage.

thats not true. most manufacturers would like to certify their products at peak draw/consumption because it looks better on a spec sheet for less money.

on this thread:

Repository of electrical measurements from grinders

BaristaBoy E61 helped show that the K30 meets its advertised power certification and likely exceeds it in real world operation.

#52: Post by **Jeff** » October 24th, 2021, 10:16 am

"Certification"?

Isn't the nameplate current and power supposed to be the maximum drawn during operation?

(That aside, measuring input power doesn't seem vary useful. It's like measuring gasoline consumption to determine a car's acceleration or top speed.)

October 24th, 2021, 11:15 am

"certification" indeed requires quotations. im not a UL/CSA/ETL expert. id expect you can find some answers in there, but maybe its not so explicit.
but ya, i think most appliances are certified for max.

id wager that most of those commercial motors - in a similar weight category - have comparable efficiencies. given that its really just the burr attached to the motor shaft, i dont think its too much of a leap to compare based on perceived (or advertised if you know the part number) efficiency.

#54: Post by **napierzaza** » October 24th, 2021, 8:59 pm

I think that ultimately the end result that I want is grind time. So the only way to do that is to potentially get them all and have them all grind the same coffee to similar espresso extraction time and see how they fair. I have actually been bothered by James Hoffmann reviews where he didn't include the time grinding in the videos where I would at least be able to time myself.

#55: Post by **LsVivaldi** » November 12th, 2021, 2:15 am

correct me if i am wrong from recollection of physics but doesn't the 10:1 reduction also up the rotational torque to the burrs?

November 12th, 2021, 2:48 am

Yes -- I assume like going to a lower gear riding a bicycle up a hill (or a manual shift car) - more torque but lower wheel speed at the tire.

#57: Post by **ira** » November 12th, 2021, 3:12 am

LsVivaldi wrote:correct me if i am wrong from recollection of physics but doesn't the 10:1 reduction also up the rotational torque to the burrs?

Yes, by a factor of ten minus a small amount for the loss in the mechanism.

Ira

#58: Post by **karamba** » December 23rd, 2021, 11:40 am

Laura wrote:Why do people pay for machines like the eg1 or monolith grinders when they have such tiny motors? As an engineer, I don't see why these machines cost so much compared to a Ditting lab grinder which have superior components for less. Are people fine with overpaying for design?

Maybe because you're are not good engineer ?

There is so much more in the grinder besides the motor. And there is so much more in the motor besides power.

December 23rd, 2021, 12:22 pm

yakster wrote:I wonder how those Niche Zero's will hold up to commercial use at David Schomer's Espresso Vivace where he's added hoppers to the Niche with large hose clamps to hold them in place.

DaveC wrote:This is a tricky discussion due to the confusion between power, torque and the way different motors handle this. Add a gearbox (Torque Multiplier) and the confusion gets worse. A commercial grinder motor has to do 2 things....start turning and be able to keep turning, plus grind quickly. Motor shafts are "usually" directly connected to the burrs. For an AC motor to start turning and keep turning through pull up torque to max torque, requires a motor of size n....but to grind fast enough might need a motor of size 2n. A motor consuming more watts, so it can do more work.

the same grinder in home use, may require a motor of size n and because it doesn't need to grind in 4 seconds, but 8 seconds a motor of size n is sufficient.

The same grinder with a gearbox able to generate the required torque with a motor of size n/2, might grind in 16s

In all cases the same total work is done over a different unit time The motors can be of size 0.5, 1 or 2. In a grinder of good design, the size of the motor should only dictate it's capacity to do work. If a grinder is prone to stalling, it's because the design of the grinder (or gearing) is such that there is insufficient torque to turn, the power of the motor is not relevant if it does not have the capacity to do any work.

A "give me a lever long enough and I will lift the world" kind of thing...For any specific grinder, the motor power (plus gearbox if any) design, ultimately comes down to, does it have sufficient capacity (torque), to do the work (weight of coffee ground per unit time) required of it.

P.S. It is also important to consider optimum burr "packing" as I call it in the design....which may well affect grind.

I agree with DaveC and will take this setup any day over the Niche - particularly in a commercial setting.

#60: Post by **Jonk** » December 23rd, 2021, 1:28 pm

Looks like quite a pain to keep 12(+) grinders dialed in