# Eureka Olympus 75E appraisal part 2



## PeterF (Aug 25, 2014)

Needless to say I left with the 75E in the boot of my car. After living with it for week or so it really is a brilliant all rounder. It delivers taste in the cup in spades, it is incredibly easy to dial in, which was not the case with the Mazzer's stiff and difficult to manoeuvre collar (I have weak wrists!) The on demand function is quick and very efficient, with surprisingly little retention. The other big advantage for the home user is that there is no pop corning, even with only a small amount of beans in the hopper. Many other on demand grinders require a significant weight of beans to operate correctly. I simply put in a 250 gram bag of beans into the hopper. When I finish grinding for the day I take off the hopper and return the balance of beans to an airtight container. I repeat this process each day until all the beans are gone & start again with a fresh bag.

Conclusion: This a very solid, beautifully constructed grinder with a seriously powerful 575 watt motor and a low 900 RPM. It is attractive to look at, a doddle to use and clean and most importantly it delivers great tasting coffee, consistently, day in, day out. Obviously there are better/more expensive grinders out there but for the Bella Barista discounted price of £749.00, including the Mythos burrs, IMO I doubt it can be beaten at the sub £1000 price.

PS.

Unfortunately I don't work for Eureka & I don't get paid any commission from BB!


----------



## DavecUK (Aug 6, 2013)

PeterF said:


> IMO I doubt it can be beaten at the sub £1000 price.
> 
> PS.
> 
> Unfortunately I don't work for Eureka & I don't get paid any commission from BB!


Glad you are enjoying the grinder, I found it to be an easy grinder to live with. I think 3 things make the difference for me, Rotational speed is lower at 900 (which I find can give a better grind), very easy to clean, which means you will clean it regularly and a very good burrset. I think the price is quite reasonable as well, considering the use you will get from it over the years/decades.


----------



## reneb (Nov 2, 2011)

thanks for the review peter. i'm thinking of upgrading my 65e at the moment, and it's good to know you could taste a significant improvement going from the sj to the 75e, and that it was clearly better than the 65e, which is what you would expect. the 75e is one of the grinders i'm considering, but may try to stretch to either the ceado e37s or the compak e8 (if i can find enough loose change down the back of the sofa!).

sounds like great service from bella barista, as ever. i am always impressed by how much time and effort they give you and how great their after sales support is.


----------



## DavecUK (Aug 6, 2013)

reneb said:


> thanks for the review peter. i'm thinking of upgrading my 65e at the moment, and it's good to know you could taste a significant improvement going from the sj to the 75e, and that it was clearly better than the 65e, which is what you would expect. the 75e is one of the grinders i'm considering, but may try to stretch to either the ceado e37s or the compak e8 (if i can find enough loose change down the back of the sofa!)..


I've got a Compak K8 for review at the moment, but if you can stretch the extra for the Ceado E37S it's worth it, of course the K8 I have may also be quite good, don't know until I test it. Also sometimes BB will sell a test unit at a better price, if someone wants to pick it up directly from me....Or if you're in the area you can always come and have a look at it. I'm only about 20 miles from London.


----------



## Nikko (Aug 20, 2014)

PeterF said:


> Conclusion: This a very solid, beautifully constructed grinder with a seriously powerful 575 watt motor and a low 900 RPM.


What is the basis for saying that lower rpm = better.

Why would a bean care at what rpm the motor is running or what the power rating of the motor is? And is it not the case that the speed of the 75E burrs at their periphery is identical to the Mignon's? Given the greater capacity of the 75E are not the beans moving faster through the 75E burrs than the Mignon's?


----------



## reneb (Nov 2, 2011)

thanks dave, definetely leaning towards the ceado e37s or the compak e8. if you have one to sell on, would be very interested


----------



## DavecUK (Aug 6, 2013)

reneb said:


> thanks dave, definetely leaning towards the ceado e37s or the compak e8. if you have one to sell on, would be very interested


It won't be me selling it, it would be BB, once I've reviewed it.



Nikko said:


> What is the basis for saying that lower rpm = better.
> 
> Why would a bean care at what rpm the motor is running or what the power rating of the motor is? And is it not the case that the speed of the 75E burrs at their periphery is identical to the Mignon's? Given the greater capacity of the 75E are not the beans moving faster through the 75E burrs than the Mignon's?


for the benefit of other people reading. Where n = rpm...using 2 pi n/60 radians to get angular velocity for Mignon it is about 141 radians per sec. For the 75E it's about 94 radians per sec.

Linear velocity at the periphery i(we don't have to worry about units) V = WR (where w is radians and R is radius in metres of burrs).

Mignon 141 x 0.025 = 3.525

75E 94 x 0.0375 = 3.525

*So yes the smaller burr Mignon has an identical linear velocity at the periphery as the larger burr 75E...*...You can't compare the Mignon and the 75E on the basis of the linear speed of the burr periphery because other factors come into play. With grinders that have burrs equal to or slightly larger than the 75E. In this case the Linear velocity at the periphery is much higher, almost double..

e.g. 1400 rpm compak K8 with 83mm burrs is around 146 radians per sec

146x 0.415 = 6.05

Does the bean care...yes I believe it will care about speed, *not necessarily at the periphery but at other points in it's journey through the burr.* It's quite probable that the speed of the burrs in the precrush and earlier crush zones is more important. I guess the easiest way to think about it is high vs lower impact speed producing more/less inconsistent particle sizes. I'm not worried about temperature at all in the home environment. However, this is just 1 factor taken in isolation.

The power rating of the motor is purely about the ability to maintain a constant rotational speed for all beans and feed situations. This is something an underpowered motor does not do well. Is consistent speed important for consistent grinding...yes, I firmly believe it is.

As for the beans moving faster through the 75E burrs than the Mignon, it's not a relevant/valid comparison to make?

You keep referencing the Mignon, and mixing things in that have not been said, it's a little confusing?


----------



## DoubleShot (Apr 23, 2014)

^^

Perhaps a little too late at night (02:44!) to get my head fully around above info but interesting all the same.

Everyday is like a school day when reading certain 'very informative' posts such as yours DavecUK

Thanks.


----------



## mrsimba (Mar 17, 2014)

Many thanks Dave for the very informative post


----------



## DavecUK (Aug 6, 2013)

DoubleShot said:


> ^^
> 
> Perhaps a little too late at night (02:44!) to get my head fully around above info but interesting all the same.
> 
> ...


If it's the radians thing, it all sounds more complicated than it actually is. The basic thing to know is 1 revolution of the burrs is 2 pi radians. So once you know the rpm, you can easily derive the angular velocity in radians (w). it's then a simple equation to convert angular to linear velocity for any given radius ®. V=wR.

This of course tells you the linear velocity at any point in a burrset e.g. you can measure where the crush zones start and derive the linear velocity at that point. Where this becomes valid is as the burrs get larger and larger and would determine for any given burr design where to start the crush path and how aggressive to make it for best performance for any given rpm of a grinder. Unfortunately I suspect the grinder manufacturers don't do any of this and don't give a rats ass about it. Some of them will have found slightly better grinding if they reduce the burr speed (trade-off in grind speed), others by moving the start of the crush zone further in.

Unfortunately with the type of motor systems they use (as cheap as they can), the rpms many grinders run at is predetermined e.g. 1350 or 1400 rpm. It would actually be quite something in terms of grind quality, if they could introduce a variable speed grinder....controllable by the user. You could then set the optimum rpm for any particular bean (or indeed burr-set and coating type). I say this because not all beans would have an optimum grind at the same rpm. So slower is better, but how slow and at what point are further gains not made.

It's a pity that grinder companies don't take consumers seriously, it being a revenue/marketing driven development...the sort of "umm shiny" stuff. Also nothing against Baristas, but often they use Barista panels to help design the grinders. This is great for perhaps usability in the commercial environment, but not for discussions like this. Also, this type of discussion is NOT one the grinder manufacturers want to have. It's similar with espresso machines, they're happy having the sort of "umm shiny" discussion, but not the more difficult ones they need to have.

I'd guess, but I don't know because I have not read the 100s of pages of stuff, that the grinder @dsc is designing would have variable speed control, because with the investment in money that has been made a variable speed motor system would have been a very small % of the total cost.


----------



## PeterF (Aug 25, 2014)

It is recognised throughout the coffee industry that a more powerful motor is less stressed and does not have to work hard. The increase torque of a powerful motor enables the grinder to operate at lower RPM, and less heat is generated. As we all know heat is bad as it has a detrimental effect on the taste. That is why a lot of high end grinders have sophisticated cooling systems built into them.



Nikko said:


> What is the basis for saying that lower rpm = better.
> 
> Why would a bean care at what rpm the motor is running or what the power rating of the motor is? And is it not the case that the speed of the 75E burrs at their periphery is identical to the Mignon's? Given the greater capacity of the 75E are not the beans moving faster through the 75E burrs than the Mignon's?


----------



## Nikko (Aug 20, 2014)

DavecUK said:


> You keep referencing the Mignon, and mixing things in that have not been said, it's a little confusing?


It has been written many times and implied in this topic that *lower rpm* is better and desirable. I question this and have used the example of the Mignon from the same manufacturer which has an identical peripheral velocity. Not sure why you think that is confusing or mixing things up.



DavecUK said:


> Does the bean care...yes I believe it will care about speed, *not necessarily at the periphery but at other points in it's journey through the burr.* It's quite probable that the speed of the burrs in the precrush and earlier crush zones is more important. I guess the easiest way to think about it is high vs lower impact speed producing more/less inconsistent particle sizes. I'm not worried about temperature at all in the home environment. However, this is just 1 factor taken in isolation.


When I asked "does the bean care" I specifically referred to *rpm. *You agree that the rpm is neither here nor there and that it is the speed of the journey through the burrs which may be important. But my point is that in the 75E the bean overall travels through the burrs faster than in the Mignon, so the received wisdom about slow being good cannot be right.



DavecUK said:


> It won't be me selling it, it would be BB, once I've reviewed it.
> 
> The power rating of the motor is purely about the ability to maintain a constant rotational speed for all beans and feed situations. This is something an underpowered motor does not do well. Is consistent speed important for consistent grinding...yes, I firmly believe it is.


No. the power rating of a motor is about maintaining the stated power for the specified duration. It is chosen (or should be chosen) to reflect the power needed to produce the given output of coffee. Taking the example of the 75E and Mignon again, you find that the power per output of coffee is similar for both, so no advantage of one over the other in maintaining more constant rotational speed, even if the assertion that a more powerful motor does this better were true, which it is not.

Considering flat burrs, it seems to me that most (irrespective of diameter) fall into one of two categories in terms of output per linear meter of burr travel, suggesting that there are only 2 basic designs. Just an observation on my part which could be pure coincidence for the dozen odd grinders I looked at, but if it is really the case then it may suggest that the diameter of burrs is not as important as made out.


----------



## PeterF (Aug 25, 2014)

Hi Guys,

Just for the record I am keeping my beloved Super Jolly. Firstly I will be using it for my French Press & secondly it's always a good idea to have a back up grinder in case the new shiney one's electronics pack up! I also treated her to nice Italian badge which looks very smart.

http://s723.photobucket.com/user/hourwerk/library/Misc/Misc%202

QUOTE=PeterF;355184]Needless to say I left with the 75E in the boot of my car. After living with it for week or so it really is a brilliant all rounder. It delivers taste in the cup in spades, it is incredibly easy to dial in, which was not the case with the Mazzer's stiff and difficult to manoeuvre collar (I have weak wrists!) The on demand function is quick and very efficient, with surprisingly little retention. The other big advantage for the home user is that there is no pop corning, even with only a small amount of beans in the hopper. Many other on demand grinders require a significant weight of beans to operate correctly. I simply put in a 250 gram bag of beans into the hopper. When I finish grinding for the day I take off the hopper and return the balance of beans to an airtight container. I repeat this process each day until all the beans are gone & start again with a fresh bag.

Conclusion: This a very solid, beautifully constructed grinder with a seriously powerful 575 watt motor and a low 900 RPM. It is attractive to look at, a doddle to use and clean and most importantly it delivers great tasting coffee, consistently, day in, day out. Obviously there are better/more expensive grinders out there but for the Bella Barista discounted price of £749.00, including the Mythos burrs, IMO I doubt it can be beaten at the sub £1000 price.

PS.

Unfortunately I don't work for Eureka & I don't get paid any commission from BB!


----------



## jeebsy (May 5, 2013)

PeterF said:


> As we all know heat is bad as it has a detrimental effect on the taste. That is why a lot of high end grinders have sophisticated cooling systems built into them.


What about the one particularly well regarded high end grinder with a 'heating' chamber?


----------



## Nikko (Aug 20, 2014)

PeterF said:


> It is recognised throughout the coffee industry that a more powerful motor is less stressed and does not have to work hard. The increase torque of a powerful motor enables the grinder to operate at lower RPM, and less heat is generated. As we all know heat is bad as it has a detrimental effect on the taste. That is why a lot of high end grinders have sophisticated cooling systems built into them.


You are right that a more powerful motor is less stressed but only in the same application. My example was of two different grinders requiring different levels of power inputs due to their differing coffee outputs.

The amount of heat generated in the burrs is less to do with the motor and more about the work done on the beans.

What would be interesting if a manufacturer offered the same grinder running at different rpms. In that case the lower rpm version would actually need a less powerful motor


----------



## DavecUK (Aug 6, 2013)

Nikko said:


> 1. It has been written many times and implied in this topic that *lower rpm* is better and desirable. I question this and have used the example of the Mignon from the same manufacturer which has an identical peripheral velocity. Not sure why you think that is confusing or mixing things up.
> 
> 2. When I asked "does the bean care" I specifically referred to *rpm. *You agree that the rpm is neither here nor there and that it is the speed of the journey through the burrs which may be important. But my point is that in the 75E the bean overall travels through the burrs faster than in the Mignon, so the received wisdom about slow being good cannot be right.
> 
> ...


1. using the Mignon to illustrate the point/s you are trying to make, is not a good comparison.

2. I didn't agree rpm is neither here nor there, where did you get that Idea...Linear velocity is important.

3. You are incorrect about this and making the assumption that the torque and motor loadings are directly proportional.

4. Again incorrect, there are more than 2 different burr designs and diameter of burrs is definitely important.



Nikko said:


> You are right that a more powerful motor is less stressed but only in the same application. My example was of two different grinders requiring different levels of power inputs due to their differing coffee outputs.
> 
> The amount of heat generated in the burrs is less to do with the motor and more about the work done on the beans.
> 
> What would be interesting if a manufacturer offered the same grinder running at different rpms. In that case the lower rpm version would actually need a less powerful motor


Eureka do with a special version of the Mythos, it had a much lower rpm, to improve the grinding and and specially at pro baristas in comps, Nuova Simonelli market the Mythos 1 and the Mythos plus with 900 and 1400 burr speeds respectively. In fact the Mythois 1 uses exactly the same motor as the 75E! For sure the lower rpm grinder uses a less powerful motor, but it would because it's doing less work and running at lower rpm. The point is

1. has the motor sufficient power

2. rpm of motor as translated to Linear velocity at the various work surfaces of the burrs


----------



## PeterF (Aug 25, 2014)

Dave has made some very good points & his knowledge on this subject is far greater than mine. All I know is that the 75E produces a better tasting coffee in the cup than the SJ & 65E. That's the main reason I purchased it.


----------



## coffeechap (Apr 5, 2012)

Nikko said:


> You are right that a more powerful motor is less stressed but only in the same application. My example was of two different grinders requiring different levels of power inputs due to their differing coffee outputs.
> 
> The amount of heat generated in the burrs is less to do with the motor and more about the work done on the beans.
> 
> What would be interesting if a manufacturer offered the same grinder running at different rpms. In that case the lower rpm version would actually need a less powerful motor


mazzer offer two similarly burred grinders the major and the royal, the royal spins slower than the major but has a more powerful motor.


----------



## mrsimba (Mar 17, 2014)

coffeechap said:


> mazzer offer two similarly burred grinders the major and the royal, the royal spins slower than the major but has a more powerful motor.


Makes sense as the slower the rpm the more torque the motor will need to produce.


----------



## Nikko (Aug 20, 2014)

coffeechap said:


> mazzer offer two similarly burred grinders the major and the royal, the royal spins slower than the major but has a more powerful motor.


The burrs may be the same diameter but what about the throughputs - are they also identical? More throughput = more power.

All I am saying is that if the same burr set is spinning more slowly, then it will *absorb *less power at the lower speed because of lower throughput (assuming of course that the grind setting is the same). (The actual rating of the motor may have to do with other factors (direct drive vs gearbox) but the plate rating should not be confused with delivered power.)


----------



## Nikko (Aug 20, 2014)

DavecUK said:


> 1. using the Mignon to illustrate the point/s you are trying to make, is not a good comparison.
> 
> 2. I didn't agree rpm is neither here nor there, where did you get that Idea...Linear velocity is important.
> 
> ...


taking the first set of your comments

1. No idea what point you are trying to make. I chose these two grinders to make the point that there is more to it than just rpm

2. As you know, rpm without mentioning the diameter is a meaningless number and you did say " yes I believe it will care about speed....". I believe that we are in full agreement on this one.

3. I have reread what I wrote and there is nothing incorrect or confusing about what I have written. If you believe that there is perhaps you could spell it out. I am making no assumption that torque and loading are proportional (they are not) but it seems that you are confusing loading and power. It also appears that you are confused about the rating of a motor as it appears on its plate and the power that motor may develop in operation. There is no reason why these should be the same or anywhere near.

4. I did not make a statement so nothing to be incorrect about. Just pointing my observation that the performance of most burrs seems to fall into one or other of two categories. Coincidence?

For the second set of comments:

1. Agree but what does "sufficient"mean. For longevity, in a commercial setting, the motor rating should match or exceed the power delivered in normal use. In a domestic setting a manufacturer might try to get away with an underrated (= cheaper) motor as slight underrating will not have a noticeable effect on performance but I do not think that they do as in terms of the power to throughput ratio most directly driven grinders seem to be much of a muchness. So not much difference in this area.

2. Agree, but again mentioning rpm without diameter is meaningless


----------



## DavecUK (Aug 6, 2013)

Nikko...whatever you are trying to achieve, or get from this thread.....good luck with it.


----------



## coffeechap (Apr 5, 2012)

completely agree with Dave, good luck in your search.........


----------



## Snakehips (Jun 2, 2015)

Back on track............

For what it's worth, my move from Mazzer Mini to Olympus 75e, prompted by Dave's initial review, echoes PeterF's good experience.


----------



## Nikko (Aug 20, 2014)

DavecUK said:


> Nikko...whatever you are trying to achieve, or get from this thread.....good luck with it.


I thought I explained . More to the point, what are you trying to achieve with the dodgy science? Any way thanks.


----------



## DevonStan (Sep 19, 2016)

Thread resurrection alert.

As I may well have mentioned somewhere else on the site...and, hopefully, for the benefit of those who might buy the Olympus 75mm from BB thinking it was 575 watts and 900 rpm..the one they most recently had for sale (the model I recently bought) is 800 watts and 1400 rpm and has the description 'High Speed' associated with it. Same burrs and, ostensibly, a similar machine but if you bought without checking you might not get what you had envisaged.


----------



## Nikko (Aug 20, 2014)

There is a lot of bullsh*t flying around regarding motor ratings, rpms and whatnot and how it translates into grind quality. Check the plate info on your grinder - it will say 800W but probably it will also say that operation is restricted timewise, say for 100 seconds every 1000 seconds. By restricting the operating time the same motor can be made to appear more powerful. It will certainly not take anything like 800W when grinding


----------



## DevonStan (Sep 19, 2016)

800 watts. 120 seconds on. 900 seconds off.

I bought it after reading reviews and opinions (most of them on here) and having tried to get a feeling for whether it would be suitable for me and my type of use (and whether it would fit on my worktop).

I'll admit that I overlooked the "High Speed" nomenclature. If it had been the 900rpm version I'd have been equally happy with it...but it is what it is and seems to suit me OK. Unfortunately I don't have the knowledge or experience to know whether it's as good as other, comparable, machines...I simply followed the thinking that a decent grinder is as important as the machine and decided that £750 was enough to spend...and compared a few different models... and, rightly or wrongly, went for it.


----------



## Nikko (Aug 20, 2014)

I thought it might say something like that - it is just a marketing trick to make the motor seem bigger than it is. At the end of the day, as long as the grinder is spinning nicely, the power rating of the motor has no bearing on the quality of the grind. Enjoy your grinder.


----------

