Welcome to my photo documentation "mini project" on the Mazzer Mini grinder (timer version with doser).

I'm breaking down (disassembling) some of the components of the Mazzer Mini as well as I can (not being a grinder tech or anything) and taking the opportunity to shoot as many of the component breakdowns as I can -- at least at the major levels.

A lot of these photos will probably be old news to some folks, but I'm attempting to put together a consolidated set of shots of different components of the grinder can all be seen in one place without a lot of web surfing. And I'll add a few photos that people might not necessarily see elsewhere, like macro and fisheye shots that can add a different perspective to everyday objects.

I have a great many photos that I've taken of the Mazzer Mini posted on my own website (more so than I will post here), but for our purposes here I'll try to take some of the best of what I've got on my site and place them in this thread.

For those who want to see the full set of photos, please feel free to visit the Mazzer Mini page on my site:

http://www.ruscelli.com/mazzer_mini.htm

If you'd like to stick to the more concise version of my photo set(s), you'll see those images by scrolling down farther into this thread.

Thanks to Dan (HB) for talking this through with me and providing his input about what he thought would work best for posting here. Maybe this thread will even give others some inspiration to do their own photo documenting of their favorite pieces of espresso-related equipment (grinders, espresso machines, even other peripheral tools or devices -- whatever sparks a bit of inspiration).

In case there's any question as to which Mazzer Mini is being shown in this thread, here is a photo (minus the standard built-in tamper) that can serve as our starting point:

The following set of photos shows the Mazzer Mini doser breakdown.



How do we get in to clean out the doser or to do a sweep modification to make the doser mechanism operate a bit more efficiently? At this point, I can't show the sweep modification, but I can show enough about how the components fit together that if someone wanted to do such a mod (or wanted to clean out the doser) they should be able to do so without going at it blindly.

For any of us taking a close look at our own Mazzer Mini, we might initially find ourselves peering in through the top the doser (after removing the finger guard) and seeing something like this:





Or we'd see something like this by looking in through the side of the doser (finger guard and plastic doser lens have been removed):



Removing the topmost screw on the center post (middle of photo, the screw that holds on the center regulator knob), and unscrewing the regulator knob itself allows the entire star assembly to be lifted out and removed (see next photo). This can be done with or without the doser shield (the clear, plastic doser window) being removed. When unscrewing the regulator knob, the star assembly must be held steady with your other hand or a screwdriver tip so that the regulator knob will unscrew without rotating the entire star/sweep assembly.



Top view of upper and middle stars after initial removal from doser. The single, stubby screw next to the spring held the regulator knob to the center post in the doser.



Bottom view of upper and middle stars after removal from doser, showing the heads of the small screws (already partially unscrewed by me) that must be removed to separate the stars and dosing sector from one another.



Doser body, middle and upper stars, star spring, dosing sector (the thin, flat, shiny, wedge-shaped piece), regulator knob, and securing screws.



Inside of doser with star assembly removed.


I know I've seen other photos like these before as associated with the sweep mod to help keep the Mazzer Mini doser a bit cleaner (by sweeping the grinds more efficiently). Part of my reason for taking the doser apart was to look more closely at doing that mod myself (as well as to do an initial cleaning of the grinder, which I acquired used and which was at least slightly in need of cleaning). If some other new owner of a Mazzer Mini was interested in cleaning out their grinder's doser, but didn't have a good visual reference, photos like these might help. Certainly, the owner's manual is not much help with this sort of thing, not showing enough detail to take anyone this far into the grinder. (Well...the version I have of the owner's manual doesn't go this far, in any case.)

This is a basic breakdown of the Mazzer Mini grinder adjustment mechanism, burr carriers, and burrs. For cleaning out excess coffee grounds and cleaning or replacing the burrs, this is a basic look at the pieces and parts involved.

A FEW WORDS OF CAUTION: So that it doesn't get left unsaid, please make sure the grinder is unplugged before attempting any of the following disassembly, if you're going to try any of this yourself. The photos here are meant for informational purposes but are not meant as professional instruction. Disassembly of your own machine is at your own risk, so please be careful if doing so. This is definitely not an officially endorsed procedure, but merely my way of visually documenting how I worked with my own grinder.


Top view of the grinder showing open doser and the grinding assembly that houses the burrs (with hopper removed and finger guard removed from doser).



Close-up view of the grind adjustment collar (occasionally referred to as the adjustment disk, dial or wheel).

To remove the collar, the vertical collar safety screw must first be loosened and the horizontal hopper safety screws should be (but don't necessarily have to be) removed from the upper burr carrier. If the hopper safety screws are left in, the collar can still be loosened enough to lift both the collar and upper burr assembly simultaneously from the grinder. The collar safety screw is not visible in this image, but can be seen in the next photos, below.



Close-up of the adjustment collar safety screw and the hopper safety screws.



The adjustment collar loosened and ready to be lifted off the grinder body.

Rotating the grind adjustment collar clockwise (with the aid of the collar handle) loosens the collar so that it can be removed. The above view shows the doser removed, but doser removal is NOT a necessary part of this procedure. The doser's absence is purely coincidental in this photo.



Close-up view of the adjustment collar and threads, fully loosened and ready for removal.



If removing the adjustment collar separately from the upper burr carrier, this is what will be seen after lifting off the collar.



Adjustment collar and upper burrs removed from grinder (shown as removed simultaneously).

As shown above, the adjustment collar and upper burrs can actually be lifted off simultaneously, if desired. (But, even if the hopper safety screws are not removed before lifting the adjustment collar and upper burr carrier from the grinder, those screws should be removed and the parts should be separated at some point for proper cleaning).



Lower burrs and lower burr carrier revealed after removal of adjustment collar and upper burr carrier.



Adjustment collar and upper burr carrier removed from grinder.

In the above photo, the hopper safety screws have been placed back into the upper burr carrier to not lose track of them. They'll need to be removed again when it's time to reassemble the grinder so the adjustment collar will slide over the upper burr carrier after the burr carrier is slipped into place. The adjustment collar safety screw may be left in place in its loosened state.



Close-up of the upper burr carrier.

Removal of the three screws that go though the burrs enables the upper burrs to be removed from the carrier (if necessary, for replacement or thorough cleaning as desired).



If the upper burr carrier is taken apart, the short hopper sleeve (which inserts into the upper burr carried) can be separated from the carrier. There is probably little need to separate these pieces unless you're being extremely thorough with wiping down and cleaning the parts.



The adjustment collar and handle, bottom thread view.



Close-up view of the bottom threads of the adjustment collar.



One of the three adjustment collar springs in its place.

Three adjustment collar springs that allow the upper burr carrier to "float" and work in a stepless manner (that is, the springs help allow the upper carrier to be raised and lowered steplessly with any minor or major adjustments of the collar, with the springs keeping upward pressure on the upper burr carrier at all times).



Adjustment collar springs.

The three springs can removed simply by pulling them straight up and out after removal of the upper burr carrier (they are not secured in place in any way once the upper burr carrier is removed, except by gravity). Careful not to lose track of them after removal of the upper burr carrier. If the grinder is turned onto its side or further disassembled for cleaning, the springs could easily fall out and be lost.



View of the bottom burrs and bottom burr carrier after removal of the adjustment collar and upper burr carrier.

Removal of the three screws from the bottom burrs enables the burrs to be separated from the bottom burr carrier. Sometimes the bottom burrs stick and must be "tapped" loose by exerting sideways pressure on the burrs (for instance, with a screwdriver or a blunt-ended instrument inserted through the grounds chute and up against the side of the burrs in such a way to enable a light tap to the outside of the burr ring).



Bottom burrs removed along with the three screws that hold the burr ring in place.

Although the above photo shows the bottom burrs, these could just as well be the top burrs, since both appear exactly the same and are held in place with identical screws.



After bottom burr removal, the lower burr carrier is revealed.


IMPORTANT NOTE FOR REASSEMBLY: When reassembling the grinder and reinstalling the grind collar by screwing it back into the grinder, BE CAUTIOUS and DO NOT CROSS-THREAD the collar threads. Take it slow and easy and make sure the threads engage smoothly. Cross-threading would likely be a mistake that's difficult (and very expensive) to correct.

Various shots (standard and macro lens photos) of the Mazzer Mini burrs.



New burrs, fresh out of the package.



The two burr rings in the set are identical



A closer look at the burr set pressed together.



This is very close to how the burr set would meet in the grinder, but with a tiny gap to allow the ground coffee to pass through.


The photo, above, and illustration, below (courtesy of HB), work together nicely to show the closeness of the burrs as they would be oriented inside the grinder and to illustrate what happens between the burrs.




My interpretation (below) of what is being shown in the illustration, above.

(Here's where I need Jim's feedback! Am I correctly interpreting where the fine/final grinding takes place? And I have used slightly different labeling for my own clarity. In Jim's illustration, I have a bit of confusion over the label that says "Coarse Grind." What I think that means is the "action" of coarse grinding and not anything to do with "output" of "coarse grind" as an output grind. But for my own clarity, I have used the labels of "Initial Grinding, Secondary Grinding, and Final Grinding." After some feedback, I might need to relabel my photo illustration.)


Bean grinding path. (Complementary photo to the illustration, above.)



An older burr ring mounted to the upper burr carrier and freshly cleaned with Urnex Grindz.



Angled view of burrs mounted to upper burr carrier.



Macro photo, close-up of burr blades.



Macro photo, close-up of burr blades.



Macro photo, close-up of burr blades.



Macro photo of new burrs fresh out of the manufacturer's package (as yet unused).

First of all these photos are fantastic. However, what amazes me is on the last photo, which is identified as a close up of the burrs directly out of the box, visibly the casting has quite a few imperfections. I would have expected crisp edges with no gouges or rough edges. I realize that as you magnify something the imperfections stand out more- even a razor blade under a microscope looks like it has serrations. But, these photos are really not that close. Now, I am reconsidering whether I really need new burrs.

You raise a valid point that was discussed at length in New grinder with poorly machined burrs and Break in period for new grinder burrs. I commented on my new grinder routine in Is this grinder break-in?

HB wrote:It's probably overkill, but I run several pounds of coffee through a new grinder to eliminate flashing, swarf, and whatnot. Initially I skipped this step in the days leading up to the Compak K10 WBC vs. Mazzer Robur taste test and noticed some grind setting drift. Counter Counter Coffee generously provided five pounds of stale coffee to break in the burrs. It's only one data point, but the K10's grind setting has been rock solid consistent ever since.

fantastic post thank you

Wow!

Impressive photos. Product photographers should pay attention. This is fun stuff.
It's great to see the basic casting and machining work evolving in the coffee grinding world.

Nice work.

tom

Very nice and informative posts! I just went to hug my Mini after reading this! All best for you!

thank you very much.