ROK Coffee Grinder - Owner Impressions

Grinders are one of the keys to exceptional espresso. Discuss them here.
alc217
Posts: 8
Joined: 11 years ago

#1: Post by alc217 »

I live in Singapore, and received my ROK grinder a couple of days ago. Finally got to try it this morning to make a V60 pourover. A few thoughts:
1) beautiful looking machine. Base is super sticky as advertised. This thing WILL NOT move while you're grinding.
2) disappointing burr alignment. I dialed it open 1 full rotation and cranked the arm, watching the gap between the burrs widen and narrow.
3) after a test grind, was fairly impressed with the apparent grind uniformity. It definitely looked pretty darn good to the naked eye.
4) today's brew only proved point 2 above. Layer of fines mud sitting on top of my V60 bed after brewing.
5) static build up is annoying, but their to tip to sprinkle water in the beans before grinding works.
6) the way the infinite adjustment dial sits below the burrs means that there's a lot of grinds that that don't make it to the container. Clean up therefore becomes messy.
7) bean hopper is a bit shallow, which means that partially ground bean bits will pop out towards the end of the grind. Similar problem in the older Harios before they started including that cap. I need to dig out that old Pringles cap I used to use for the Hario and see if I can use it for the ROK.

I also own 3 other hand grinders: Hario Skerton (with a 3D-printed add on to try to stabilise the shaft near the burr), a Porlex Mini that I bring to the office, and a Portaspresso Rosco Mini.

The spring mechanism used to hold the conical burr in place reminds me of the Porlex, and the resultant fines is very similar. However, I still feel there is better grind consistency than the Porlex. Absolutely no comparison against the Rosco.

I guess for the price paid, I shouldn't have expected Rosco quality... That having been said, it IS a lot easier to grind, compared to the cylindrical grinders that I own. Will need to start tinkering this weekend to see if I can stabilise the drive shaft better and reduce the wobble (a la Hario?).

Someone separately asked me whether or not I noticed any drift in the adjustment wheel. At this point, no...but now I need to actually pay attention and see if it actually does. Will report back over the weekend.

vit
Posts: 981
Joined: 9 years ago

#2: Post by vit »

Spring between the inner burr and lower bearing, if similar as in Porlex (which is, I suppose, similar to hario slim) is probably not an issue. Burr is pressed down by the coffee during grinding anyway. First Lidos didn't have anything to press the burr down, Lido 3 has a security washer above the burr, but there is some free play between it and burr + some vertical free play of the axle in lower bearing, but it's not an issue

Problems could be radial free play between inner burr and axle, between axle and bearings, between outer burr and housing etc ... I'm just guessing as I didn't see the internals and they are not visible in promo video. If you can post some photos, it would be nice

Are the burrs similar quality like in Rosco or look like low grade chinese burrs found in new Zassenhaus grinders ?

Generally, I like the idea of this grinder, however I was expecting these problems, having in mind the price and already reported quality problems with Rok espresso maker

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lpranal
Posts: 24
Joined: 15 years ago

#3: Post by lpranal »

Well this really isn't the kind of feedback I was hoping to read :( I was hoping from the specs that this thing would be a decent step up (in terms of grind quality) from my capresso infinity for espresso. I've been making do with it for a few years now and gotten my technique (and espresso machine) down to the point where the grinder really is the only thing holding me back. Now I'm starting to wish I had just gone with a used MDF or something similar. Unless the burr wobble is more of an issue with the larger grind settings (for pour-over / press). Anyone used this for espresso yet?

HoldTheOnions
Posts: 764
Joined: 9 years ago

#4: Post by HoldTheOnions »

You can't align the burrs on this machine?

alc217 (original poster)
Posts: 8
Joined: 11 years ago

#5: Post by alc217 (original poster) »

Sorry for the delay in the responding... been travelling overseas.

I need to retract a bit of my original comments. I spent 1 weekend trying to tinker with it and realised that it's most likely not an alignment issue, but a burr issue. The drive shaft is rotating true and it's held in place at the two end (near the burr and at the other end). So I only assume that the burrs themselves aren't the best match for each other, resulting in some contact during rotation.

I read somewhere else that you simply need to break in the burrs, because none are perfect (except for those Swiss ones, apparently). I don't know if they look more like the newer Zassenhaus or not. They don't look exactly like the Roscos either. Will need to take some photos to compare.

I will say that I've taken to use the ROK every weekday morning now to make my pourovers. It's definitely faster than my Rosco. I'm still going back to my Rosco on the weekends when I have the time.

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JohnB.
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#6: Post by JohnB. »

No issues with the adjustment dial?
LMWDP 267

Bak Ta Lo
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#7: Post by Bak Ta Lo replying to JohnB. »

John,

Was hoping they would have got the US grinders delivered by now, I saw their email today that they are in the process of shipping to USA customers, so hopefully it will be out soon.

I have had more time to play with the grinder since I first mentioned not liking the grind adjust setup, and that it has some drift. Now that I am used to it I am a less annoyed by it, the drift amount is very small, and it is finite in amount, if I set the wheel to grind setting number 1, it drifts exactly a quarter inch past 1 by the end, but no more. So it is not continuously drifting, just shifting a small amount from the initial setting after it is set, hope that makes sense. I do still wish it could be truly locked in place. For my Rosco the opposing lock rings keep the position, my Lido wing nut locks the setting, and for my Pharos I have the Teflon tipped set screw to lock the setting. I am still looking and thinking how the ROK could get some sort of grind setting lock.
LMWDP #371

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JohnB.
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#8: Post by JohnB. »

Evidently a few folks on the West Coast have received shipment confirmation from WLL & UPS tracking numbers. I believe that started last Friday. I'm 2 days UPS from Buffalo, N.Y. where they are shipping from & haven't heard anything but promises that show up in the weekly ROK updates. Judging from the Update I received from ROK today some folks are getting very upset about the situation.

Since it would seem that the grinders sat in Buffalo for a month before shipping started I'm hoping that they might have updated some of the problem areas. If mine ever shows up I'll let you know.
LMWDP 267

vit
Posts: 981
Joined: 9 years ago

#9: Post by vit »

There is a relatively useful review

http://www.poisonvine.com/review-rok-coffee-grinder/

lpranal
Posts: 24
Joined: 15 years ago

#10: Post by lpranal »

Regarding the burrs not matching perfectly - I'll give Rok a pass on this one. It took me three tries (!) to get burrs that lined up properly on my capresso infinity - it's not such an easy task, especially in this initial run. My guess is that's what's been taking place at Wholelattelove for quality control. If I had to venture further, I'd say they were probably promised a certain tolerance from the production in China, and when they started shipping realized they weren't up to par. Whether this is the case or not, only time will tell - but either way, I think most customers (myself included) if they had just been open about this and communicated to the contributors who helped make this thing possible.

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