Reviving an Abused Cimbali Max

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cannonfodder
Team HB

#1: Post by cannonfodder »

I few weeks ago I purchased a Cimbali Max on eBay after reading Jim's review and conversing with Ken and other Max owners. I wanted to get more clarity than my Mazzer Mini or Cimbali Jr provided. I had the Mazzer Kony for a few weeks and was just not satisfied with the cup it produced. The cup was too lively and bright for my taste. The Max, with its hybrid conical crusher burrs and fine grinding plainer burrs appeared to be just what I was looking for. The Max would provide more clarity than my planar burr grinders but not give me the overly bright and lively cup I got from the Kony. So I cast my lot and won my grinder.

The machine arrived in a rather bad state of disrepair. It was mechanically sound but utterly filthy. The grinder has been stored for several years, with beans in the hopper. The burrs were caked in old coffee beans, the doser and hopper had a thick residue and film in them. You could barely see through the plastic. So a thorough teardown and cleaning was the first step. The Cimbali Max tears down relatively easy. Three screws and the hopper comes off. Once removed, the worm gear adjustment ring must be removed, three more screws and it lifts off the upper burr carrier. To remove the upper burr carrier, you simply unscrew the carrier and lift it out.

Grind index and burrs after the cleaning

The upper burr carrier contains two parts, the crushing conical burr and the upper flat fine grind burr. Both are held in place with three screws. Once the screws are removed the burrs simply lift from the carrier. My unit was dirty I had to use a screwdriver to pick away the caked on beans to get the burrs apart. Once disassembled I soaked them in some backflush detergent and gave them a good scrubbing, once cleaned they look good as new. The lower burrs are removed in a similar fashion. Three screws and the planar burr lists off the burr spindle, the lower conical crusher burr is bolted to the motor shaft. I had no need to remove it.

Upper burr - conical/flat 64mm


Upper burr (oriented as when installed)


Burr carrier and lower burr - conical/flat 64mm

To further disassemble the machine you must remove the outer stainless steel shell. There are two small Phillips head screws with a small nut backing them on the left and right from sides of the grinder. A small pair of needle nose pliers and a small Phillips head screw driver easily removes them. That will separate the body shell from the front of the grinder. To remove the shell, you must lay the grinder on its side and remove 3 screws from the base of the machine, shown here unscrewed but laying in the holes. Once removed, you stand the grinder up on the base and take the shell off exposing all the interior workings.


To further disassemble the machine the doser must be removed from the front panel. To be quite honest about it, I did not write down detailed instructions so I do not remember the exact steps, but it is relatively easy to remove and this is what I remember.

Under the doser is a black plastic shroud that covers the doser handle and springs, two screws and it comes off. The grind adjustment worm gear must also be removed, again two screws and it lifts off the top of the inside of the grinder. Around the exterior of the plastic doser window are three black trim pieces. They are held on with small clips and very tiny Phillips head screws. Once the screws are removed the trim pieces can be removed. Inside the doser, the dosing vanes are attached to the doser shaft via the doser adjustment knob. You will need to hold the doser vanes with one hand while turning the adjustment screw to the left. It will unscrew from the doser shaft and the entire assembly will lift out of the doser. Once removed, you can remove the last two doser mount screws which are located under the doser in the front panel of the grinder.

There are two more screws in the base of the grinder that are holding the front panel on. To remove them you will need to carefully tip the machine on its side. Be careful, since the shell is removed the interior parts are exposed and susceptible to damage. If you drop it on its side you could damage the capacitors. Once those screws are removed, the entire front of the grinder comes off and the doser pulls out.

Once I had the grinder stripped to the frame and motor, I gave all the parts a soak and wash in JoGlo to clean up the old caked on coffee oils. It cleaned up quite nicely, most everything looks like new. The reassembly is the same as the disassembly, just in reverse.


Modification one, that annoying auto doser fill switch and toggle power switch. Inside the doser is a large flap. That flap works a switch that is mounted in the top of the doser. In a busy commercial environment, you would turn on the main power (rocker switch) and let the grinder fill the doser. As you dose your shots, the doser slowly empties and that pressure switch opens and the grinder starts grinding until the doser is once again full. In a home environment that is not practical. While I had the doser apart, I simply took a pair of needle nose pliers and straightened the retaining pin that held that flap in place. Once removed the power switch is used to activate the grinder. With the auto-grind flap removed you can easily sweep out the grind chute.

Modification two, the rocker power switch. The power switch on the Max is a large rocker style with a plastic membrane covering it. That membrane protects the switch from stray grounds and water but makes using the switch a bit clunky. Ken suggested I just remove the cover, so I did. That made a vast improvement in the usability of the switch. However, I still preferred the push button switch that Cimbali used on it Jr grinder (my other grinder is a Cimbali Jr).


While I had the machine apart I noticed that the switch look to be the same size and hookup as the push button switch the Jr uses. So I dropped T.J. (our resident Cimbali master importer) an email. A few days later a new switch arrived.

The switch is easy to replace. You must remove the hopper from the grinder as well as the shell (5 screws). Once the grinder open (and UNPLUGGED!) you simply disconnect the spades from the original switch, squeeze the retaining clips in and push the switch out the front of the grinder. The new Jr switch then snaps into the frame, plug the spades back in and put the shell back on. You now have a push button power switch. That switch is very easy to hit with your thumb while thwacking the doser. It beats the pants off the Mazzer timer switches. You do not have to let go of the doser handle to turn the grinder off and on. Just hit it with your thumb while you are dosing.


Modification three, that annoying shelf above the grinder burrs. Above the upper burr carrier is a shelf, or pocket. That pocket will hold onto beans and requires some cleaning between blends. You have to reach down through the hopper with a brush to sweep the beans off that perch. Many people have added a small extension inside the doser to eliminate that shelf. While I had the top off the grinder to replace the switch I decided to add an extension. My problem, finding a small, short piece of tubing to use as filler for the burr throat without making a trip to the hardware store. I looked at one of my kids plastic cups, to big, a hunk of PVC pipe, too large, nothing in the garage. I thought of using a water bottle but again, what I had on hand was too large. So I sat there staring at the hopper trying to come up with an idea. Then it hit me, the hopper on the Cimbali grinders has this annoying little center riser that serves no purpose but to get in the way. It just happens to be the same diameter as the burr throat on the grinder. Eureka, use what is at hand. So I remove the riser and head to the garage.

That riser is too tall so out comes the Dremel and a cutoff wheel. I cut the tabs off and shorten the tube by nearly half. The upper burr carrier has three notches on it. These are where the burr carrier screws attach to the brass carrier. Mark the insert and cut the notches in the insert. When finished, it drops into the burr throat and the drop extension on the bean hopper sits inside it. Wala, a useless part now has a function.


Disclaimer, that useless piece of plastic is actually a finger guard. So if you are prone to sticking your fingers into sharp steel burrs spinning at high RPM, you may want to leave the cone in the hopper. Then again, you may want to have someone hit you in the forehead with a ballpeen hammer as well.

Now I have two holes in my bean hopper that use to be the retaining clip holes for the riser. You do not want opening in your bean hopper because beans will fall through and end up on the inside of your grinder. Again, another super high tech fix, two small strips of scotch tape.


Good as new and ready for a life of service.



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Dave Stephens

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Ken Fox

#2: Post by Ken Fox »

Great job, Dave!

Thanks for the explanations and the pictures.

ken
What, me worry?

Alfred E. Neuman, 1955

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TimEggers

#3: Post by TimEggers »

My appreciation too Dave, as I hope to one day rescue a Max for myself. Well done!
Tim Eggers
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LMWDP #202

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cannonfodder (original poster)
Team HB

#4: Post by cannonfodder (original poster) »

I wish I had taken more photos but I had the machine half cleaned before I thought of it. To appreciate how it looks now, you really needed to see it before I started. I literally had to use a screwdriver to chisel the oily fused bean mass from atop the burrs.

I am quite happy with the performance of the grinder. The change from a Mazzer Mini was quite dramatic. Even the Cimbali JR, with its Super Jolly sized 64mm burrs is dramatic. The clarity is much more pronounced and the cup livelier. It brings out the more subtle, and acidic flavors in the bean. I do notice a slight drop in the low, earthy, chocolate tones. They are still there but not as 'in your face' as they once were. I have actually reformulated a couple of my blends to take advantage of this characteristic.

I have very satisfied with my purchase. I wonder with one of the older DRM Cimbali hybrid grinder with the 68mm burrs would be like.

Here is the eBay photo, but it still looks clean compared to what I got. Look at the portafilter fork, the inside of the machine was much worse.

Dave Stephens

Cafesp

#5: Post by Cafesp »

Wow, impressive!

I wonder if the Cimbali Junior grinder can be retrofitted with the new Max Hybrid conical burr set?
Love is in the air, Taste it!

Ken Fox

#6: Post by Ken Fox »

There are two problems with this; the motor is apparently different between the Max and the Junior, and also, Cimbali, the sole source for the mixed burr set, will charge so much for that burr set that you might as well buy the new grinder.

ken
What, me worry?

Alfred E. Neuman, 1955

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cannonfodder (original poster)
Team HB

#7: Post by cannonfodder (original poster) »

I had the same thought, and came to the same conclusion as Ken. I also believe I read somewhere that Cimbali does not sell the conical burr assembly since they should never wear out and only the flat burrs would ever need replaced.

The cutting teeth on the Max flat burrs are different than those of the Jr burrs. The Max burr set does not have the large bean crushing outer burr teeth. If you were to stick them in a Jr burr carrier, I doubt you would get a decent grind, if any at all. They beans may just bounce around in the grinder throat.
Dave Stephens

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Hobzon

#8: Post by Hobzon »

I have just bought a used La Cimbali Max grinder, and am currently in the process of dissasembling the grinder for cleaning. I have gotten everything apart, and cleaned, except for the Burr carrier and lower burr - conical/flat 64mm knives.

The bolt that holds the lower set of burrs seem to be locked in place, and I simply cannot figure out how to loosen it, so I can clean the lower conical and flat burrs as well as the housing underneath (the casing that is part of the upper motor assembly.

Any advice?

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zix

#9: Post by zix »

Well, if you find out, do share. I am curious too of this.
As to the conical auger burrs never needing replacement, I am not so sure. I have recently seen a pair that looks ready for replacement.
Do the conical burrs need to be sharp? They only crush the beans, but still...
LMWDP #047

Hobzon

#10: Post by Hobzon »

I gave up on removing the bottom conical burr - I am sure there is a trick to removing it, but as the grinding chamber itself appeared remarkably clean, and I was easily able to remove the grit from the conical as well as the bed on which the burrs is fixed, I opted against waiting in preference of getting to grind my first shot with my "new" grinder - and WOW what a grinder!