Aligning 1Zpresso burrs?

Grinders are one of the keys to exceptional espresso. Discuss them here.

#1: Post by syc »

I was mildly curious about the Z-P6 grinder after Lance's endorsement video. I've seen examples of products Lance endorsed actually kind of sucking (lately there have been a slew of complaints about the Camperista3D chute for the DF64 which Lance wholeheartedly endorsed), so obviously its important to take the endorsement of a social media influencer with a grain of salt. However, what was interesting about the Z-P6 is that it seemed to use the same burrs as the discontinued JS, however with improved alignment. Which led me to wonder if anyone has tried improving on the factory alignment of the 1zpresso grinders, to see how much extra clarity they can squeeze out of the grinder.

There's this one lonely video on the topic:
Anyone else tried this? Or is the factory alignment already so good that you'd be chasing basely detectable improvements?

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#2: Post by Pressino »

To answer your first question, No I haven't tried it because my JX-Pro arrived with burrs well-aligned. Mr. Maurice makes it clear his grinder lost alignment because he went too far in disassembling it. My experience with 1zpresso is that the company is very responsive to consumer questions and complaints. I got a grinder from them (J-Max) that had a coating defect on one of the burrs, emailed them a photo, and they exchanged the grinder for a new one (and shipping was paid by them). So if your grinder is out of alignment (due to their manufacturing error) I'm fairly certain they will fix the problem. I suspect they might even fix it for you if you ship it to them at your expense if you created the problem by misuse...

You could check your grinder's alignment by using the method Maurice discusses in the video. If it is within specs, I'd suggest leaving it alone. Otherwise, you could try the technique (sequentially adjusting the burr set screws until its withing alignment specs), with the caveat that you will void your warranty..

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#3: Post by Brewzologist »

Just got a new Q2. For reference the burrs stopped touching once I got to the 7th click out from full burr lock. Given a full rotation (30 clicks) moves the burr 0.75mm, I'd say that's darned good for a new grinder. And based on prior experience aligning a Lido ET, I'd also say if it ain't broke, don't fix it. 8)


#4: Post by Jonk »

It's probably better to at least season the grinder first before attempting anything like that. With a brand new K-Max I was getting burr rub around 17 clicks (roughly equivalent to 19 on a JX in terms of burr travel at least). It's down to 6 after seasoning at coarse settings and calibrating.

I had a Kinu M47 before that didn't rub at all until complete burr lock.. So I'm guessing this K-Max has worse alignment. Still plenty of available settings for espresso and it grinds a lot better for pour over in my opinion. Tried removing the outer burr a few times without success. Perhaps it's a good idea to get a model with a screw in catch cup for better leverage if you want to attempt to align the grinder.


#5: Post by iyayy »

i think italmill burr have a flat surface at the cone edge, while k burr have teeth all the way. it is possible to slot the inner teeth between outer teeth, possibly going to less than 0, i.e the cone goes inside the outer burr pair, while margin for italmill is probably only up to 0.

i dont have a kinu, but here's arco. visually i can assume kinu (also using italmill) have more gaps to avoid burr rub even at its closest touch point, while k burr can overlap tooth before it even touches each other. 7 clicks 1zk are also pure dusts.

if comparing flats, burr chirps are light touch and can still spin. but flattening both burrs will fill burr gap and jam it.


#6: Post by Jonk »

I agree that burr geometry might be part of the difference. Yes, the Kinu M47 Italmill burrs would stop with the bottom of the cone burr completely in line with the bottom of the ring burr.

The carrier on the Kinu M47 was about the same size as on your K so it was easy to check just by running a nail from the cone to the ring, but on my K-Max the carrier is like the one on your Arco (a bit annoying, because it means having to remove the cone burr in order to clean off grounds stuck below the teeth of the ring burr)..

but you're saying the K burr can basically do this to some extent?

My guess would be that 7 clicks is finer than the lowest useable setting on a Kinu M47. Grinding is slow, at about 2-3g/min, producing a nice turkish grind. On the Kinu the burrs would spin perfectly but without actually grinding anything on too low settings.
iyayy wrote:if comparing flats, burr chirps are light touch and can still spin. but flattening both burrs will fill burr gap and jam it.
Not sure what you mean here.


#7: Post by iyayy »

Jonk wrote: Not sure what you mean here.
here's a negative gap for flat burr. it has already pass touch point or chirping. if u turn on ur grinder here u will likely break something

i'm just saying its possible kinu burr will never overlap due to the straight wall, therefore can still spins without rub while not allowing any grinds through, with 1z still allowing grinds to pass even at burr rub due to this tooth overlap (while damaging your burr edge instead).

i am not denying that your theory is correct, but it would also mean you will need proper measuring and machining tools to make micron adjustments. i dont see this any difference than the usable but similarly flawed marker test for flat burr alignment in this context since those are already best case without the need of specialty tool.

regardless, it may be possible that the outer burr mount screw can be tightened with different tolerance enough to affect the outer burr position. you can try do this adjustment and see if you can probably reduce the burr rub down to 2-3 clicks instead?

i have tried slowly turning my 1z k. at 6 clicks there is a minor rubbing sound only at specific degree of turns, suggesting offset-alignment. slowly turning however and i have coffee dust accumulates between the inner and outer burr exit throughout the circular exit, suggesting grinding is still possible. it gets almost jumpy at lesser clicks, i didnt try further. its probably making extreme use of the bearing play by that point.

comparably to the timemore c2 shaft is very much centered. c2 bracket is plastic and can warp (permanently) even under beans load (forced mis-alignment xD) my grinds are coarser with more boulders on c2 compared to when its new (i still use it in office). i now grind finer but the cups are still enjoyable.


#8: Post by Jonk »

Sure, even with very good tools it's still down to speculation what the alignment is like during actual grinding.

The burr rub I get at 6 clicks is a quick squeal at one specific point per rotation. I'm going to leave the mounting screws alone because a) it works fine and b) I'm not sure I can improve alignment but pretty certain it could end up worse :wink:

I believe this is all secondary to burr geometry anyway, as long as the alignment is good enough. Using the (all metal) Timemore G1 as an example I'm more convinced that it had worse alignment than the Kinu M47, but I much preferred pour over using the Timemore. I enjoyed using both of those grinders but overall I like the K-Max better and I don't think the relatively small differences in alignment matter nearly as much.


#9: Post by kennelcoffee »

I just got a JMax myself and found that the factory zero setting was at least 10 clicks from the burrs touching. I followed the guidelines in the manual for calibration and found the same as what you did I believe. That if I stopped just at the point of the burrs touching with discernable feedback I was only getting that at a couple of points in the rotation. Annoying perhaps but I'm not losing any sleep over it. I mean we're talking adjustments of .0088mm right? But just where should the zero be set?

I calibrated mine so that I just get that feed back when at the factory zero mark before I used it for the first time. I then started with a pour-over and went to 270 clicks, right in the middle of their recommended range for that brew. The resulting grind was a bit too course for my liking and brew method but it was certainly very uniform visually.

I started to just look at 1Z's chart for recommended grinds and I can't say as it's lining up with recommended grind sizes based on microns. I mean if 0 is not grinding, 1100 microns should be about 125 clicks. But that's more like the middle of their recommended espresso range. Not that it matters. I was just playing with the math and trying to see how their grind chart worked within that 8.8 micron adjustment. I was thinking it would be nice to be able to say I want to go to an 800 micron setting and to do the math and then dial it in. I wish I hade a set of Kruve screens just to find a benchmark.


#10: Post by Jonk » wrote:These three kinds of adjustment design share a common point of the zero setting: at the click which the crank handle is unable to move drastically.
..but since you should avoid grinding with the burrs touching, you could just as well calibrate to one click above the first burr touch and just compensate for the number of clicks that is above true zero.

The vertical travel per click does not translate to an equal amount of burr gap, especially not in the finer range.
It was fun to play around with a Kruve but it's really not very useful in my opinion. Just trust your tastebuds instead.