Mazzer Robur uneven grinds?

[samuellaw178]

I am single dosing too and it takes around 10 sec to grind as well (can measure it properly if you like). With hopper it took around 4 sec (3.x) indeed.

[rackxp]

Could you take a photo of the ground coffee? Could you weigh out a double shot and tell us how long it pours for?

[skidquinn]

Did you buy genuine burrs? Are you grinding to fine? That's still too long in my experience. Should be around 4 seconds with new burrs.

Yep and my grind is only as find as it needs to be to produce good shots from the Silvia.
I'll check the grind speed tonight when the hopper on it and report back

[rackxp]

Did you buy genuine burrs? Are you grinding to fine? That's still too long in my experience. Should be around 4 seconds with new burrs.

[skidquinn]

Is it still taking 12 seconds to grind 20grams of coffee?

Timing has improved as well, but is not where it should be yet. At a guess I'd say closer to 8-10 seconds for 20 grams. However, I have only been single dosing the grinder, which causes it to grind slower than with a hopper & beans above it. Might test this tonight.

[rackxp]

Is it still taking 12 seconds to grind 20grams of coffee?

[skidquinn]

Hi all - just to update on this one for anyone that may run into the same problem down the track and find themselves here.
Seems like the burrs on the Robur have already started to settle. I've put about 1kg of beans through in the last week or so (both to drink and play/dial in) and the quality of the grinds (and resultant) has improved drastically.
I am back to using this as my grinder of choice.

By the sounds of the advice received here, it seems it should improve even more over time as well, so am glad I changed burrs. Also glad to have this website as a sounding board for all things coffee related. thanks guys

[samuellaw178]

Can you post a picture of how your grind looks like?

[chokkidog]

Well, to be fair, if you're going to pass it on you should sort the issue first, otherwise it's gonna be a fire sale! :-D

Who wants a Robur grinding at Super Jolly speed? Something is definitely up.

Might pay to pm or email Rick @ Coffee Machinist (site sponsor) and see if he can throw some light on it.

[dumiya]

Hi, it is just remotely possible that the motor shaft is not true. It may be possible to check this by removing the top burr and placing a piece of paper over the lower burr then ever so slowly replace the top burr and screw it down until it just touches the lower burr then winding it off to see if the touch is all the way around. It can be done with two pieces of aperture will carbon paper between. It should leave a mark all the way round.

[skidquinn]

I wouldn't give up!

Why don't you take it in to a good coffee tech (or get them to come to you). It could be a simple adjustment. Another thought- if you see my photos of my Nino which I posted last night, you will see I have fitted a glass vertical hopper. This definitely makes the grind more consistent when using small quantities of beans like in a domestic environment. You could try a temporary system such as a PVC pipe or similar. Put a tamper on top of the beans to keep a constant down pressure. If it works, then go for the glass custom-made version like mine- others have used perspex- could be a bit cheaper than glass- I prefer glass because it doesn't scratch and looks the part. Worth a try before dispensing with such a beautiful machine.

I saw that - the glass hopper looks epic. Yep, had some good plans for this grinder...... A nice repaint and some sort of custom hopper. Just wanted to make sure I was happy with how it was grinding first. I'll have a bit more of a play and see if I can get any improvement. I'm just not sure I love it enough to bother with sending it to a tech or having one out.

[Gavisconi007]

Far out..... 2k shots is about a year at the rate I use it....... haha. Will take your advice on the rice though. Thanks!



I haven't timed it exactly, but I reckon somewhere between 12-15 seconds for ~ 20 grams. Compared to the old burrs that were well under half of that.



Have tried both with my usual single dose and with ~ quarter hopper full of beans. Same result unfortunately. I think the auger is supposed to assist with this.

I guess the recurring theme here is that these beasts are simply not designed to be used domestically.......... Makes keeping this thing just a little harder. Thanks for your help guys!!

I wouldn't give up!

Why don't you take it in to a good coffee tech (or get them to come to you). It could be a simple adjustment. Another thought- if you see my photos of my Nino which I posted last night, you will see I have fitted a glass vertical hopper. This definitely makes the grind more consistent when using small quantities of beans like in a domestic environment. You could try a temporary system such as a PVC pipe or similar. Put a tamper on top of the beans to keep a constant down pressure. If it works, then go for the glass custom-made version like mine- others have used perspex- could be a bit cheaper than glass- I prefer glass because it doesn't scratch and looks the part. Worth a try before dispensing with such a beautiful machine.

[skidquinn]

Don't grind rice.

It will settle once you see about 2k shots...

Far out..... 2k shots is about a year at the rate I use it....... haha. Will take your advice on the rice though. Thanks!

What is 'super slow (for a Robur)' in actual time? And for how much grinds?

The issue with the new burrs is one of those things you get with a commercial grinder in a domestic situation.

I haven't timed it exactly, but I reckon somewhere between 12-15 seconds for ~ 20 grams. Compared to the old burrs that were well under half of that.

How full is the hopper when you are experiencing these issues? I have read elsewhere that the Robur needs to have a decent surcharge of around a quarter to a half of the hopper being full of beans in order to create sufficient down-pressure onto the grind chamber to ensure consistent grinding. Perhaps this is part of the equation?

Have tried both with my usual single dose and with ~ quarter hopper full of beans. Same result unfortunately. I think the auger is supposed to assist with this.

I guess the recurring theme here is that these beasts are simply not designed to be used domestically.......... Makes keeping this thing just a little harder. Thanks for your help guys!!

[Gavisconi007]

Hi all
Relatively new here and hoping for some advice regarding a Mazzer Robur E and an issue I seem to be having with uneven grinds. I picked up the Robur through my brother a number of months ago for a price that was too good to resist. It had been used in a commercial environment and has ~ 7000 on the counter. I think year of manufacture is 2010. When I purchased it, it had a sticker on it indicating that the burrs were changed in May 2013.
My previous grinder was a Gino Rossi RR45 (which I believe appear rebranded as numerous other brands) and at first, the Robur seemed to produce much better coffee in the cup than I could manage with the Gino Rossi.
Over the last few weeks I think I've noticed that there are very very small bits or chunks after grinding through the Robur. The quality of the espresso has been pretty ordinary as well and I can't seem to get a shot on the bottomless portafilter that doesn't shoot everywhere at first, and then blonde far too quickly.
To make sure I wasn't going mad, I've fired up the Gino Rossi again to compare and have no such issues. The coffee is great.
I am using home roasted beans which are no more than a week old, so should be no issue there.

My guess is that I need to replace the burrs, but have read that Robur burrs should last anywhere up to 800kgs of beans? The counter suggests (unless its been round the clock completely...... maybe multiple times??), that it hasn't had that volume through it? Should I just replace them anyway? Are burrs from 2013 considered old?
Are there any other reasons why this would happen? And why its only happened since I bought it?
I have pulled it apart again and given it a good clean (burrs and all) but this hasn't helped.
Realise its hard to make a call without knowing volumes through it though.....

Any thoughts?
On a side note, it is such a beast of a thing, I'm still deciding whether I will keep it long term. My wife thinks I'm completely mad, but has been surprisingly tolerant with my new obsession!!

Thanks

How full is the hopper when you are experiencing these issues? I have read elsewhere that the Robur needs to have a decent surcharge of around a quarter to a half of the hopper being full of beans in order to create sufficient down-pressure onto the grind chamber to ensure consistent grinding. Perhaps this is part of the equation?

[chokkidog]

What is 'super slow (for a Robur)' in actual time? And for how much grinds?

The issue with the new burrs is one of those things you get with a commercial grinder in a domestic situation.