ROK Coffee Grinder - Owner Impressions - Page 7

Grinders are one of the keys to exceptional espresso. Discuss them here.
pav2k
Posts: 17
Joined: 8 years ago

#61: Post by pav2k »

orduek wrote:Good to hear.
I'm still unable to get a fine enough grind for my LaPavonni Pro.
I tried realignment, I will try it again soon. I get burr contact while grinding but still, not fine enough.
:(
I believe everyone experiencing the same. On some kind of fresh beans 70-30 arabica robusta ratio I've managed to pretty much choke my Rancilio Silvia, on other single origin beans especially two weeks+ freshness I couldn't stretch the brew for more than 15 seconds...

m03ppp
Posts: 24
Joined: 10 years ago

#62: Post by m03ppp »

The point where the Burrs no longer move without excessive force (the rok zeroing method :lol: ) has moved by a full number since I first got the grinder.

So perhaps it'll be possible soon, depending on how much you use the grinder?!

Beaniac
Posts: 179
Joined: 9 years ago

#63: Post by Beaniac »

What are your brewing results and how much coffee have you passed trough the grinder to get to that state?

I've gone trough my entire "stale" bucket seasoning and starting to feel a bit sad feeding quality coffee to gushers.

m03ppp
Posts: 24
Joined: 10 years ago

#64: Post by m03ppp »

Beaniac wrote:What are your brewing results and how much coffee have you passed trough the grinder to get to that state?
I've gone trough my entire "stale" bucket seasoning and starting to feel a bit sad feeding quality coffee to gushers.
Not much perhaps 300g + ~150gr rice.

I wrote previously (ROK Coffee Grinder - Owner Impressions):
m03ppp wrote: The espresso I currently get with the rok grinder tastes rather flat and more earthy compared to a Major or EK43. I suspect this is because a lower extraction due to greater particle size spread I get from the rok grinder. This may be the fault of the play, but could also be caused by a sub par burr set (are there any high quality small conical burrs?), I don't know. I'm trying to up the extraction to get the taste I know but I haven't measured the extration to verify my theory.
I have been successful in trying to up the extraction by dosing lower and grinding finer. I don't know how much of that improvement is due to burn in thought (apart from being able to grind finer).

Main main issue currently is that the conical burrs produce much more crema and crema doesn't taste very good :?.

The rest tastes more or less like I would have expected it to. But I may have grown accustomed to the rok's flavor profile. Who knows!?

Additionally the grinder is squeaking under high load. The squeaking comes from the mounts/bushings of the axle that attaches the handle. It's gets worse during grinding and gets better is you stop every 10s for a few seconds, so it may be heat related!?. Lubricant helps but it's not easy to get the lubricant into the plastic bushings and behind the bevel gear (and I don't know if the lubricant damages the plastic?!).

lpranal
Posts: 24
Joined: 15 years ago

#65: Post by lpranal »

One observation I'd add (both from my own experience and reading that of others) is that the quality of espresso with this grinder seems to be very much affected by the bean's origin and roast. Not a huge issue for me since I roast my own beans and they are always very fresh, but it may become problematic to some who don't always have the freshest beans.

One example, the costa rica I had been working on when I first got the rok grinder produced incredibly bright, fruity shots. This had been apparent with my capresso infinity, but suddenly it's much more pronounced. Just roasted some Brazilian Cerrado and the difference is night and day. Still really good espresso, but the flavor profile had changed dramatically despite having the same roast level. Very cool to be able to pick up all the idiosyncrasies of single origin beans, it'll be fun to try and come up with my own blends finally

victorsmiller
Posts: 3
Joined: 8 years ago

#66: Post by victorsmiller »

I had high hopes for the Rok grinder, but, unfortunately for me, the one that I received appears to be defective. No matter how I tried to adjust the grind it always came out the same. When I removed the adjustment wheel and washers, the burr was still locked in place, and I can't get it out. No wonder I can't adjust the grind! This doesn't speak well for quality control.

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JohnB.
Supporter ♡
Posts: 6579
Joined: 16 years ago

#67: Post by JohnB. »

The burr key is sticking on the shaft. Remove it & clean up the D shaped opening in the key with a small file. I found that the flat section of the opening is slightly high in the middle & catches on the shaft. Remove a little material so that it is truly flat & the burr will slide up & down freely.
LMWDP 267

victorsmiller
Posts: 3
Joined: 8 years ago

#68: Post by victorsmiller »

After a lot of fiddling around, I seem to have fixed (for now) the problem. I found that the burr key was slightly twisted on the shaft (the flat parts of the D didn't line up). When I removed the washers and only used the adjustment wheel I was able to tighten it all the way. When I untightened it the burr was now free. For now I'm leaving the washers out (I'm fine with the "clicks"). One strange thing -- now the tightest setting on the wheel is "9". Very strange.

Rappy
Posts: 57
Joined: 10 years ago

#69: Post by Rappy »

victorsmiller wrote:One strange thing -- now the tightest setting on the wheel is "9". Very strange.
Not really that strange since you removed the washers, whose heights represented where the adjustment was zeroed for.
You re now able to tighten it past 1 for about 3-4 clicks to find the new closed position. But you can recalibrate the adjustment wheel back to zero if you prefer, as in one of the ROK videos I saw somewhere. You will need a metal punch.

Rappy
Posts: 57
Joined: 10 years ago

#70: Post by Rappy »

Something interesting I discovered today is that the Baratza Preciso burrs seem to fit the ROK. I cannot confirm 100% as I only lined them up visually, I didn't actually swap them out. They are highly regarded small conical burrs, so would be interesting to see if there is an improvement from the saeco ones.