MKXR/MK7R Conical Burr- Worth the upgrade?

Recommendations for buyers and upgraders from the site's members.
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mrgnomer
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#1: Post by mrgnomer »

Hi all. I haven't heard much about these new Macap's Chris' Coffee is carrying http://chriscoffee.com/products/home/grinders/mxkr

So what's the opinion? Would they give a better grind than a flat burr? Are they worth a serious look? Anyone going to do a review on them soon?

I'm asking mainly because I'm looking at upgrading to an A3 Sixties Elektra from a Silvia. I paired the Silvia with a Rocky doser and while the Rocky's o.k., from what I've read and my experiences with the Rocky a better grinder for the Silvia would have been a stepless Mazzer or Macap.

I don't want to go the save a few bucks route on an upgrade and Macap's conical burr looks to be an excellent grinder to pair with a machine like the Elektra. Anyone have any hands on experience with either MKXR or MK7R? Are they better grinders than a good flat burr? Would either one be a better choice to pair with a very good machine? What do you gurus think?


jason_casale
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#2: Post by jason_casale »

Hi while I am not familiar with the macap conical grinder. I have heard it was designed to be on par with the mazzer kony conical grinder. Conical is better than flat I believe it is more gentle in grind and shaves the bean per se. So if you can get a commercial conical do so. however I believe as Mr. Schomer does the best grind is from a combo of the 2 one flat burr and one conical inconjuction. DRM a company who developed grinders with this burr set was bought by the la cimbali company. Cimbali makes a max commercial grinder with the original drm burr set. But the key difference between it and the original drm grinder is that it is direct drive meaning the burr assembly is connected to the motor. The original drm was belt driven separating the motor from the burr assembly reducing heat to the coffee. In a high volume environment this would be a concern however in a low volume environment it really is not because the heat has a enough time to dissipate between grinds not effecting the coffee. You may want to look at the versalab grinder for personal low volume use it has the belt drive and the drm burr set but from first hand experience it is difficult to load bean into it and it can only grind a small volume at a time. Good luck with the grinder dilemma it is a tough one.

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mrgnomer (original poster)
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#3: Post by mrgnomer (original poster) »

Thanks for the advice, John.

Right now the versalab M3 is a bit out of my price range. I also trust the advice of David Schomer about a mixed burr system being the best. In his Espresso Coffee Professional Techniques book he also says that between flat burr grinders and conical burr he gets thicker, deeper, longer shots from a conical burr grinder. I imagine he's comparing commercial grinders but still it adds to the dilemma of flat vs. conical.

I'm going to look into the Cimbali grinder. I know Cimbali's flat burr was rated equally well against Mazzers and Macaps but I believe the review concluded that the micro adjustment of the Cimbali would make it more of a dedicated espresso grinder. I found a vendor for the Cimbali max but it advertises it as a conical burr, not a mixed burr grinder. It's also almost the cost of an M3 grinder as well. :?

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cannonfodder
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#4: Post by cannonfodder »

I have a Mazzer Mini and Cimbali Jr. Personal preference, I like the Cimbali better, but the Mazzer has more kitchen space visual appeal. Neither is conical. The conical machines I have seen have been way out of my price range, and most are way too big for my home, Versalab being the exception.

Grinder Burr Types Explained (flat, conical, DRM)
My HB Birthday Cimbali Arrived!!
Dave Stephens

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mrgnomer (original poster)
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#5: Post by mrgnomer (original poster) replying to cannonfodder »

Thanks for the advice, cannonfodder. After a few months with a Rocky I regretted not getting a Mazzer.

The thing about the MKXR and the beefier MK7R is that they offer a commercial grade conical burr set, worm gear stepless at a pretty good price. Sure, they're about $300-$400 more than a Mazzer Mini, Macap M4 or Cimbali Jr. but those grinders are about the same amount of money more than a Rocky. The question is are the conical burrs worth the extra price compared to flat burrs especially if you want to pair the grinder with a good espresso machine?

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another_jim
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#6: Post by another_jim »

The evidence from espresso lovers suggests that conical grinders tend to perform better than flats; with the advantage becoming more obvious as the roast level gets lighter. This is also true for regular brewing.

The DRM hybrid burr set I tested in the M3 (see "The Bench" section) does all its grinding in the flat section, the conical section only acting as an augur to crush the beans as they enter the flat burr set. The advantage is that the flat burrs have a much longer grinding surface, since they do not need to take up real estate for bean crushing.

Image

In general, I believe the longer the coarse grinding section on a burr set, the better the grind. Even well mounted home grinders, like the Innova/Pavoni/Lux set work as well as small commercial flat burrs, since they have the same length grinding surface. True commercial conicals have the longest surfaces of all (the current Cimbali Max is a true burr grinder as far as I know).

Greg Scace had the same results comparing the Kony to the Cimbali Junior as I did in the M3 versus Mini comparison.

My experience with the M3 does not lead me to recommend it for anyone except people who cup coffee on a weekly basis, where the configuration comes into its own. The belt drive and burr mounts need to be tweaked every two weeks, and its usability for PFs is horrible. If I hadn't got addicted to the taste, I'd be back to the Mini in a flash. So the low cost of the Macap is very tempting, even to me.

There is one design problem with conical burrs housed in a conventional espresso grinder: the grinds exit. Since the rotation speed of these grinders is 400 to 600 RPM, rather than 1200 to 1800, the vanes that sweep the ground coffee out of the grind chamber into the doser move at 1/3 their intended speed. Therefore, grind clog-ups are a common issue to all the conical models. If you go for this or any other conical, get yourself a curved stick tool that can sweep out the chute whenever you grind, and check that the chute is easily accessible in the model you buy.
Jim Schulman

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mrgnomer (original poster)
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#7: Post by mrgnomer (original poster) »

another_jim wrote: There is one design problem with conical burrs housed in a conventional espresso grinder: the grinds exit. Since the rotation speed of these grinders is 400 to 600 RPM, rather than 1200 to 1800, the vanes that sweep the ground coffee out of the grind chamber into the doser move at 1/3 their intended speed. Therefore, grind clog-ups are a common issue to all the conical models. If you go for this or any other conical, get yourself a curved stick tool that can sweep out the chute whenever you grind, and check that the chute is easily accessible in the model you buy.
Thanks for the excellent info and advice. It's what I was hoping to hear and confirms some reading I've been doing.

The clog up issue with the low rpm'd conical burr is so obvious. Thanks for pointing it out. I grind for dose and brush out the chute and sweep clean between shots so I don't think clogging will be a problem. Actually, my concern is the size of the MKXR/MK7R: it's twice the height of my Rocky and it's going to seem a bit ridiculous grinding just for dose with such a beast.

So the reasoning behind using conical burrs to rough cut the beans in a mixed burr set and allow the flat burrs, which now can be cut for a greater fine grinding surface area, to finish the job, is that the conical burrs do a better job at rough cutting. Is it the quality of the rough grind that determines the final quality/eveness of the grind? Does that make the rough grind more important than the fine grind? Is that why conical burrs do the rough grinding and flat burrs finish off the job of grinding for fineness in a mixed burr set? This is interesting stuff :)

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another_jim
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#8: Post by another_jim »

On the DRM set the conicals do no cutting, crushing or anything else -- they augur the beans into the flat burr space, and the beans crush against each other as they enter. You will notice on burr pics, single burr sets have widely spaced claw like burrs at the entry point to get the beans into the ground surface. This usually takes up a lot of real estate (surprisingly so on the illustrated Macap burrs).

The point is that the simplest way to measure a grinder's upper potential for quality is how gently the beans are ground; this equates to how long the beans spend getting coarse ground. This is proportional to the width of the closely spaced burrs divided by the motor RPM. In the real world, jerkiness in the motor drive, imperfections on the burrs, misalignment, and vibration would all detract from the potential level a grinder could achieve.
Jim Schulman

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Jepy
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#9: Post by Jepy »

I always thought there was a certain amount of pre-breaking from the conical part in the DRM, so I took a closer look. The Versalab cone and cone ring are slightly different from the original DRM it was designed after. Maybe in the Versalab the cone is just an auger, but in the DRM, the cone and ring do a considerable amount of pre-breaking.



It's almost like a gauge, with the smaller beans slipping past without damage:

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Fr. John
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#10: Post by Fr. John »

I don't want to step on any toes here, as I find this stuff fairly interesting, my nerdishness always wins out, especially in reading.

However, this thread brings up an interesting notion, to me at least, and that is what seems to be an ever increasing "audiophile" syndrome to the world of home prosumer espresso. I find it hard to believe that there can be any appreciable benefit from an $800 grinder, clearly not intended for home use, over its smaller $400+ brother. Furthermore I would venture to posit, ever so precariously, that not only is there no appreciable benefit for a home user but that this trend may actually hinder or cobble the end users results, i.e. the form will far outweigh the function and result in a less skilled individual who has all the greatest stuff. Just look at the really high end audiophile stuff and you'll know exactly what I mean.

I may be way off here though, it may just be my practicality talking.
Fr. John

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