Hi all, 


I just had to post after reading and seeing all the talent and intelligence on the boards. My issue is a difficult diagnoses over a forum, but any help is appreciated. 


The company I work for has a Mazzer Robur E they bought last year as a trail grinder, in hopes to implement them in our 2 shops.  Long story short, I took it home, cleaned it out, plugged it in and hit grind. Shockingly after a hour of trying to dial it in. It was grinding a 20g in 9.6 seconds at best...  Also, the grinds where warm. Even after letting it sit a minute or 2 apart.


I know how great these grinders are and had the chance to play with one at intelgensia's lab in NYC. 9.6 seconds is not even close to what there capable of or what theres was producing... After talking with my boss, he said he had the same results hence why it has been collecting dust on our parts shelf... 


This leaves me with 2 conclusions. One, I am pulling a noob and if someone would be nice enough to walk me through a set by step on how to dial in this beauty. I would be very thankful. Two, this grinder unfortunately was manufacture defect or damaged in shipping.  Where would be the best place to get this fixed in the (NJ/NYC) area? Or is there something I can do my self to diagnose? I am a bit mechanically inclined or I like to think so. 


Thank you in advance for your replies. I look forward to adding what knowledge I have to barista exchanging! 




P.S. I should have mentioned that when adjusting the grinder. The grinder adjustment ring took a little mussel and took 3 to 3.5 times to where I could begin dialing in.  I was think stripped threads on the adjustment ring....:(


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Well, you are correct, 20g in ~10 seconds is way to slow. I am wondering, have you pulled shots with the coffee you are grinding? My first guess would be that you have it set WAY too fine. The warm grounds also would be and indication of this. At the settings ours is at, we get 21g in ~3.5 seconds.

So heres my experience with roburs. With the older ones, thats how long it takes to grind(about 10 sec plus or minus 2 seconds, for 21 grams) Theres no auger on the older roburs, the auger cuts the grind time in half, as its forcing beans down into the burrs. Apparently you can not just buy the auger(ive seen that talked about on other threads) from mazzer. But nothings stopping you from making/sourcing one. All it is is a stupid little metal screw thing, that bolts into the bottom burr.


Ive worked on older roburs and they got insanily hot, like you touch the burr carrier after 3 or 4 hours of pulling shots and its getting close to being to hot to touch. I dont know what exactlly caused it to get so hot. But im guessing the zero to minimal cleaning ever done on them was the culprit. I now work on brand new robur e's and you can seemly pull shots on them forever with out them getting even slightly warm. They also grind about 19 grams of coffee in 3 to 4 seconds.


Hope that helps

First off thank you both for you comments.  


Kevin, I am going to swing back around and mess with it a bit more. I want to revist my setup and see what performance I am able to get out of it.  I know at one point I was grinder to fine.


Dustin, are you referring to part 43 in this schematic of the robur e: http://www.espressoparts.com/MazzerRoburEGrinderParts If so I do have that auger. We bought this grinder in may of 2010. I believe it is the newer models.  That is why I'm so puzzled.. 


I don't want to be over zealous, but would a video of my setup process help. Thanks again guys, it is very helpful.



Ya, part 43 is it. How old are the burrs? Man thats really wierd that its grinding so slow. Have you tried different outlets? maybe the voltage is too low on the outlet its plugged into. Is the hopper full when your test grinding with it? Im sure a video couldn't hurt figuring things out.
It does sound like dull burrs to me. Of course, if the threads have been stripped, it could have a similar effect if the burrs are only slightly off-level.
Don't know off the top of my head, but all the Robur E's have the auger implemented to my knowledge.  My First thought would be dull burrs.  Could happen easily with a rock or other debris.  If you are pulling decent shots at the 10 second grind time, I would replace the burrs.
Dull burrs could definitely be the culprit. I would also check to make sure it's not crossthreaded. Shop I used to work for bought 5 brand new roburs, we were having a ton of trouble with the first one we pulled out of the box and it turned out it had been cross threaded in manufacturing. If this is the case, someone in your area should be able to remachine the piece for you very easily.

Wow Dustin, Jason, Keith, and Jonathan, thank you so much for you time in trying to help, you advice means a lot and going to re inspect my burs!


Here is the update.


I took the grinder to, where we purchased, 1st line equipment in Manalapin, NJ for a in house consolation. The fellow Jim was a very nice guy and took time out of his day to try to help.  He cleaned it out and ran a few shots. He tried his best, but we seemed to have different styles/theories when extracting. Unfortunately, after finessing with it for about 45 min. It was still not performing well in grind time, around 8-9 seconds. I nicely implyed the grind was taking quite a bit of time. His response was as importer was he never saw a Mazzer Robur E grind close to 3 seconds. I have read all over the place that the mazzer are known for there low RPM and amazing grind time! Hence why they are used in competitions and high end shops. 

Anyway, I wasn't going to argue with him. The machine is out of warranty so there is nothing he could do anyway... 


With that, I made a short video other day. I figured some of you guys that are using Robur Es might be able to help me confirm my theory in excessive grind time. Would be nice to confirm before I really start throwing money at this grinder that has been doing this brand new, out of the box from day 1.... bummed.


Click for video link: http://www.youtube.com/watch?v=Kaug8kCqJOE


Thanks again guys for all your opinions and input means alot!




I know for a fact that a properly tuned robur e only takes 3-4 seconds for a double (17 grams-ish).  8-9 seconds is most certainly longer than normal. 


So I take it that the burrs were not replaced in your consultation with 1st line?  If I were a betting man, I would guess that this is the underlying problem. 

Agreeing with Keith and everyone else who says that the burrs are the problem. Watching the video, I can't figure out any other reason it could take so long. FWIW today I changed (slightly) the blend of espresso we are using, and went from 3.40 seconds to 3.55 seconds in grind time.



You guys are awesome! thank so much for your help, you saved me a lot of money! I will try and get some high res shots of the burrs soon.  do you know a good outlet for burs? 





Peach, just sent you a private message, will need to friend me to see it though.

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