Mazzer Super Jolly Deconstruction

Mazzer Super Jolly Deconstruction
(Note I refer to Rhys several times. He sold me the SJ and is a moderator on
http://coffeeforums.co.uk, I was going to post all of this document in HTML/Wiki mark-up and
wanted him to be aware. Given size of text and number of photos I think a PDF is the way to go.)
Corrections / observations / questions are welcomed, I shall work them into this document and keep
it current as much as I can.
I am contemplating adding the reconstruction project (after paint job) at the end of this document,
but also pushing it into a document on its own. Together it is a complete journey I guess, thoughts
gratefully received.
One further note, the actual process of deconstruction was not in the same order as presented here,
I have not remarked upon this but I reckon some folk will notice from the photos. Regardless I don’t
think the comments are compromised by the photographic evidence.
Once we have a peer reviewed document that people are happy with I would be happy to
deconstruct and post as HTML/Wiki. Keeping it in this form allows evolution on a common source.
So on with the discussion:
Required tools:
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Crosshead screwdriver – for various screws,
Flat screwdriver about 6mm for those none cross head screws,
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Set of Allen keys,
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A pair of long nosed pliers,
A sharp flexible kitchen knife or similar – to remove the external stickers,
A firm steel blade – such as a plasterers trowel – to remove the Mazzer badge,
A large diameter socket,
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A long M8 bolt and nut,
A large washer fitting around the M8 bolt,
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Gas for your blow torch
A blow torch if you ain’t got one (note you might not need one of these, read all this to make
up your mind) maybe a hot air paint stripper,
Soft faced mallet
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A socket extension bar – to allow you to give in to the urge of whacking something when you
can’t get your hammer in!
Advised Parts:
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New burrs? I bought this machine on new burrs courtesy of @Rhys. You can find various
replacements all over the place in different metals to suit your whim. I am no expert, so
provide no further advice on this. But replacing the burrs is most probably the simplest thing
you can do to this machine. And given the overall cost of the machine, steel burrs are really
really cheap. No advice from me about the merits of Steel vs Titanium – I watch many male
interest forums and laugh at the snake oil claims I read sometimes…it is up to you.
New bearings, if you go down this whole deconstruct route I personally think you would be
mad not to replace ALL bearings (all 2 of them) regardless of how they might feel.
I went for fully sealed bearings…which I have been advised can be noisier…but I will grind on
this machine for about 15 seconds max each time. Will see how new noisy bearings sound
compared to grindy broken quiet bearings in the next week or so. The bearings you want
have a definition number of 6202. If you are in the UK I recommend a company by the name
of ‘BearingBoys’ they sorted me out before when I bought a 50p brass reducer to put a
rancillio v3 wand on my classic, and got the new races to me within 2 days.
Note the bearing number 6202 – I went for sealed SFK ones, originals were not so….rubber
shields instead or the like apparently. Not sure of the difference really, but these ones cost
me about £14 incl VAT & delivery (for two).
Upper bearing cover plate, this is just a disk of 52mm diameter. Expect to damage the one
already inside the grinder when you try to lift off the upper burr carrier. You may not, but
having a spare in hand will keep you flying if you do, it is cheap less than £1 GBP.
Another established member at the already mentioned forum, turned what I viewed as a
disaster into a simple purchase, thanks to @jeebsy.
Thanks to @Rhys, that’s all I needed to replace.
Precautions:
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Bear in mind the grinder body is cast aluminium. Be careful about striking anything inside it
with hammers. I’m not an engineer, but can see that it is manufactured to very fine
tolerances and a misplaced blow might disturb that. If using impact techniques put a buffer
in place such as a wooden block.
The bearings in a Mazzer are the same as those in a Yamaha moped which are the same as
those in a Hotpoint washing machine which are the same as in……Bearings are manufactured
by bearing manufacturers….and supplied to white good (coffee grinding) manufacturers
who PRETEND they have a unique bearing race and charge a premium. Don’t pay for
commonly had bearings packed in a Mazzer badged bag.
Procedure
Remove the grinder from the power supply!!!
Remove stickers:
Using a flexible sharp kitchen knife to initially ‘shave’ under one corner so aiding the removal by
careful peeling.
Remove Mazzer badge:
Using same kitchen knife gently lift the badge so that a more rigid metal blade (I used plasterers
trowel) can be inserted to prize out the prongs that penetrate the grinder body.
Remove the grind adjustment collar:
remember it is reverse threaded…unscrews clockwise….when it stops don’t force it, remove the
locking screw
Lift off the upper burr carrier:
no screws / bolts involved. I didn’t actually photo this step, but it is essentially the piece sitting in
the middle of the shiny metal in the picture above.
Retrieve the adjustment/balancing springs
The screw driver points at one of the three springs to be removed. They sit loose in their seating.
Now visible is the mounted lower burr which is the moving part of the burr pair.
The springs and the upper burr on its carrier are pictured below.
Remove top bolt from the rotor:
you will need to prevent the motor rotor from turning to achieve this
I saw this on another site; push a clothes peg (UK sorry) into the doser feed chute or something
equally softer than the moving parts. The aim is to stop the rotating parts rotating when you
attempt to unscrew the bolt on the same axis.
You will see a point on the rotor that the peg will lock if you spin it around slowly whilst looking
up the chute. Note the above picture shows the M4 bolts in place through the lower burr carrier.
Remove the doser assembly:
The first point to make here is that the doser assembly on this machine had previously been
dismantled and thoroughly cleaned by @Rhys prior to me purchasing the grinder. The automatic
components had also been removed by him so the removal of this component was simply
achieved by removing 2 allen key bolts and 2 screws.
I also removed the doser fork at this point; just two screws.
Remove lower burr from its carrier:
This gives access for the next step, and is simply removing the three screws and lifting the burr
upwards and out. The burr and the screws plainly visible in the picture above with the red
screwdriver.
Remove the lower burr carrier:
The first point of frustration.
Here three M4 bolts are inserted into the screw holes used to fasten the lower burr in place on
its carrier. Fortunately these holes penetrate all the way through the carrier and allow the M4
bolt to contact with the grinder body. In driving the bolts downwards the aim is to ‘jack up’ the
burr carrier sufficiently to slide it off the rotor.
Originally I bought some nice SS M4 bolts with an Allen Hex Key head. Probably my mistake but
these at 50 mm in length were threaded only for the first 20mm or so and not up to the
job…Make sure you get something threaded for the full 50 mm. You will probably need it.
So being nervous of the short thread for the above bolts, I decided to call in to a relatively local
hardware shop – heart-warmingly they describe themselves as ironmongers. It is like Olivander’s
wand shop in there. If you’re local I really do recommend a visit…They sold me exactly 3 of M4,
M5 & M6 bolts (because I still didn’t know for sure what size I really needed [IT WAS M4] I am in
no way affiliated – but the said iron monger is in Tadcaster, N.Yorks
Having bought the supplemental M4 bolts I started screwing.
The original Hex M4 bolts were not long enough as stated above…they stopped short prior to
lifting the burr carrier off the rotor. So despite the normal flat screwdriver profile in the bold
head, the Tadcaster bolts won the day.
Remove the upper bearing cover plate:
So now we’re left with a cruddy brown surface and a bright rotor shaft sticking through it.
The old coffee completely hides the upper bearing cover plate, a 52 mm wide disc and the three
screws holding it in place. You can see the three imprints that my M4 bolts left behind.
Here is my big mistake. I ignored the brown crudd and figured I should lever off the upper
bearing retention plate…why? I really don’t know…but it is a lesson learned in checking what
might have been learned before (or even the Mazzer schematics!)…Three screws beneath the
crudd would have released the retainer/cover plate. Instead I tried to lever it off.
That said my earlier M4 bolt movements actually perforated the bearing retaining disc, so I
guess I had already wrecked it.
This is what I was left with.
With hindsight, I am not sure there is any way to avoid the perforation damage to this item
when using the M4 bolt method to lift of the burr carrier. So I would recommend that if you are
going this far with a deconstruction you obtain a replacement.
We are now left with an upper bearing exposed and solidly wedged into the finely machined
grinder body. It ain’t coming out without a protest. Sorry no photo, but we can see where the
bearing sits here after it has been removed. Also note the damage to the casting caused by
those M4 jacking bolts !!!
Switch attention and open the grinder up from
below:
Invert the grinder, and open up the underside. Even the base plate is surprisingly sturdy (plate
steel) and removing it reveals a wiring loom beyond expectation. I guess some of it is due to the
automated dosing mechanism and is now superfluous in my case.
Beyond the switches and terminal block and green light we see a large capacitor. This is
mounted on a piece of circular aluminium about 12 – 15 cm across. This is held in place by four
screws and houses the lower bearing in which the rotor is seated. The middle circle in this disc is
the ‘pot’ in which the lower bearing is seated.
After removing the four screws, my hopes that the rotor assembly would drop out (from the
upper bearing) unaided or the lower bearing carrier would separate from the lower bearing
leaving it on the rotor foundered. It all held solid.
On to the next step.
Remove on/off switch
The on/off switch is a simple pair of screws to remove from the outside of the grinder body. It is
the brown piece in the photo above.
Switch attention back to the top and knock the rotor
out of the upper bearing:
This allows the lower bearing carrier disc to fall free of the grinder body.
So I righted the grinder with a towel placed inside the exposed underside and hit the top of the
rotor with a plastic faced mallet.
The rotor dropped free of the upper bearing and along with the lower bearing and its carrier fell
onto the towel.
The next two pictures show the removed rotor (still attached to the lower bearing carrier) and a
view inside the now evacuated stator. On the stator picture note the two small screws that
‘secure’ the item in place simply by marginally overlapping the steel body.
Label and Disconnect wiring leading from stator
assembly:
We now have the rotor assembly still linked to the stator via the wiring. Trace the wiring that
emerges from the stator, all lead into the terminal block shown next. Make note of which wires
are connected to which terminal in the terminal block, label them too, and to back it up, take
photo’s.
We now have the rotor, lower bearing / rotor carrier and base plate free from the grinder body.
Remove capacitor and earth lead from lower bearing
carrier:
The capacitor clamp and earth lead were not easy, I could not shift either of the bright screws
from the carrier.
In the end applied some heat from a blowtorch on the other side of the carrier, the invisible
expansion was enough to free up the screws. I slid the capacitor out of the clamp before
applying the heat.
Now we had the rotor locked into the bearing which was locked into the bearing carrier, all
completely free from wiring etc.
Separate the rotor from the lower bearing:
In the centre of the lower bearing carrier is a small c.5mm hole.
Insert a small M4 bolt in here and tap with a hammer. The rotor was easily displaced from the
bearing, once again confounding hope that the bearing would be pushed out too, where a
simple puller could have been employed to remove it from the rotor shaft.
Remove lower bearing from lower bearing carrier:
This looked like it might be difficult. Even if I had an inner bearing puller, there was no way that
would have succeeded because there was no space to work such a tool in. So, inverted the
bearing carrier so bearings were face down, and applied a blow torch to the carrier cup. Bearings
fell out of the cup after about 4-5 minutes, and no other physical assistance needed.
Once cooled, and handling the bearing, it seemed as if it was all sweet and undamaged.
Remove upper bearing from grinder body:
Without the help of my neighbour this step might still be on-going.
After knocking the rotor out of the grips of said bearing race, it remained very positively fixed in
the grinder body.
So with just the stator the other thing remaining inside the grinder body we could see through
the bearing races inner aperture from both directions. Fortunately the bearing is seated in a
‘cup’ with an opening that is larger than that of the bearing race itself.
So this is my neighbours Majik; using a long 8-10mm bolt, a few nuts to fit the bolt, a large
socket exceeding the outer diameter of the bearing –it looked something like this.
You might as why not tap the bearing out with a drift/bar from underneath? Well It might be
possible, I tried it with a moderate (gentle probably) tap, but I was worried about either
distorting or even breaking the casting by doing so, the pull technique is a more coercive method
with no sudden shocks applied.
On removing this bearing race, and on handling, it could be felt to be running rough and so the
presumed source of noise when the rotor was spinning.
Remove stator from grinder body
The stator fits extremely snugly within the aluminium casting. As pointed out above there are
two retaining screws to be removed.
Sadly there is little opportunity to knock the part free of the body so the only way I could find on
the web was to bake the combined parts in the oven.
So I masked the exposed cables from the stator in foil, stuffed a few tea towels inside the
grinder body to catch the stator if it fell out of place, placed it onto an enamel tray and cooked
the lot at 160 Celcius for about 20 minutes.
This did not work immediately and took several attempts. Each time using a wooden block as a
buffer I attempted to knock the stator down, gaining access via the hole left by the removed
doser.
Knocking from this position actually can push the stator out of true (tilting it) as it descends
which resulted in it jamming in place for me. Turning the grinder upside down and gently
persuading it back to its correct alignment allowed me to finally get it out.
The last picture of the following three shows the rotor, stator, lower carrier and new bearings
alongside the now completely empty grinder body.