Idfixe wrote:Why would you want to change the burrs on such a good grinder as the MAX?

Reminds me of the old song, "Why does a dog lick his (you-know-whats)? 'cause he can, 'cause he can..."

Looks like fun experimentation.

Once you get an idea of the thickness you want, brass shim stock is pretty cheap, easy to cut to size and well suited to leveling or adjusting coffee burrs. I've cut thin brass stock with scissors or even a box cutter, then just filed the edges to de-burr it. Thicker stuff can be clamped or glued between 1/8" plywood and cut with a scroll saw easily and clean up the edges with minor hand filing.

But brass is harder than aluminium, isn't it?

culturesub wrote:Curious to what taste impact you are getting on pour over. I have a MAX I only use on filter, so wondering how that worked for you.

luca wrote:I don't want to create an impression of having better results than I do. Valid and useful comparisons are a lot of work. I've done more anecdotal stuff.

The SSP/Titus old geometry Mahlkonig burrs made incredible pourover. I got like a 26% EY v60 that didn't taste overextracted and was oozing with aroma and flavour, from Morgon's filter brewed Kenyan coffee. These burrs can't really go fine enough for espresso. I haven't really played around enough with the Max burrs for filter to have useful comparisons, but these things were great. In fact, I'd probably say that that was the best made/extracted v60 I have ever had. But I've had a lot of terrible v60. Those EK burrs had been sanded on the back side of one burr, presumably because Hansung thought they weren't parallel otherwise.

I might get around to doing more, but no promises. Like I said, this wasn't ever supposed to be a thread for results.

Bluecold wrote:I'm sorry if I implied you were doing it wrong, I don't think you are, but I was just wondering if the monolith manual prescribes a tightening procedure.
The cylinder head was just an example of a similar engineering problem, with a soft interface between two pieces of metal that need to be mounted exactly parallel.

Sorry, that last comment wasn't directed at you. I aldready had a screwdriver that has a minimum torque of the target torque for the bolt. It doesn't do smaller increments. That's why I was asking. I think there's some Wera driver that can do small increments and still hit the target torque, but it's several hundred dollars. If you had a cheaper solution, I, and others I'm sure, would like to know.

Thanks for taking the time to share this Luca. I really appreciate and enjoy reading the post.

As a background context for others, EK43 has different versions of burrs over the years (both by SSP and by Malhkonig/MK themselves). There have been some anecdotal observations (since not many people have access to all the different burrs) that the burrs that work better/easier for espresso (SSP, post-2014 MK coffee burrs, MK Turkish burrs) are not as good for brew. They also behave more like traditional espresso burrs than the pre-2014 EK coffee burrs that shot to its fame. Like Luca, I am curious too what are the actual differences between the burrs style, and if the prior observations were true. So being able to change the burrs (without the alignment being one of the variable) would allow one to test that hypothesis. Well, that's in theory. In reality, it will still take a lot of work and effort to come to a conclusion confidently, so this is just a baby step towards that.

Some previous discussions on the different burrs style:
Mahlkonig EK43: Standard vs. SSP burrs for brewing
Mahlkonig EK43S Grinder Observations/Discussion

On the shim issue, I wonder if you can use one of those feeler gauges? If they can fit in there as is that would be a perfect solution. If not, perhaps cutting some of the thinner ones and stack them would be a viable option?

Thanks for adding the background reading, Sam! Hopefully there will be a time in the near future when we can get together and taste some coffee off these things!

samuellaw178 wrote:On the shim issue, I wonder if you can use one of those feeler gauges? If they can fit in there as is that would be a perfect solution. If not, perhaps cutting some of the thinner ones and stack them would be a viable option?

No, the feeler gauges are made out of steel, I think, and I don't want to chop them up in any event. I don't want to use anything harder than aluminium for fear of damaging the carrier.

We're not talking about a shim here that's designed to shim up one side more than another. It's a shim to uniformly push the top burr closer to the bottom burr, since the top burr isn't thick enough. So the shim is probably better at full width, not a small shim on a little bit as for levelling. I guess you could use three chunks. But there's no real need. The plastic binder cover is allegedly 50nm, but the actual thickness doesn't really matter; only the variation in thickness from one side to another. If that's 10%, then there's 15nm of error across the three. It's maybe not great, but for what I had on hand, I think it's good enough.

If I was doing it properly, I'd probably hunt down some soft-ish aluminium shim stock. But, then, if I was going to put effort into minimising the error any further, it wouldn't be worth it unless I had some better way to measure flatness than a whiteboard marker.

luca wrote:I haven't watched that video, nor have I used an EG-1, but what I'd point out is that most of the pfaffing around is about being meticulously sure that there isn't any ground coffee getting anywhere that it shouldn't, and I would have thought there would be lots of ground coffee to be cleaned meticulously from any grinder. If ground coffee jammed between a burr and a burr carrier is an issue, it's likely to be an issue on any grinder. Maybe moreso with smaller burrs, since presumably it will make a proportionally larger difference. Seems ridiculous to me to buy a grinder on the basis of superb burr parallelism and then take chances when swapping burrs.

Mazzers and Macaps are even worse, in that to change the burrs you have to unscrew the upper and lower carriers and it is basically inevitable that grounds will get into the threads, impacting grind adjustment as well.

Hence my point. The hole idea about monoliths is to take away all possible equipment flaw impacting the espresso, burr alignment being one of the most common problem...

Idfixe wrote: Hence my point. The hole idea about monoliths is to take away all possible equipment flaw impacting the espresso, burr alignment being one of the most common problem...

Sorry, for clarity, is your point "isn't it better to never open up the max at all so that you never risk screwing up the burr alignment?" If so, it's a good point and I think my answer is that I'm comfortable that I'll be able to put it all back together without meaningful issues, but I'm keen to find out how the other burrs perform in what is hopefully a very parallel alignment.

Well, the manual says "Monolith is designed to be easily cleaned inside by taking off the top plate and gaining the access to the grind chamber. We do not recommend cleaning grinder often, maybe once or at most twice a year. While performing cleaning you must make sure that all mating surfaces are absolutely clean since this might affect burr alignment."

So just opening it up seem to be expected. Of course you're going further and swapping burrs which probably have somewhat different alignment from the original burrs. That seems like it's the error prone part of this experiment.