# Mazzer Major questions



## mokapoka (Jun 20, 2011)

I bought a second hand Mazzer Major and I am in the middle of cleaning it out. All the doser parts are now clean, except the one in the picture. I am hesitating how to clean this since it has some grease. If I clean this with soap and water and then drop it in Cafiza, would I need to re grease it? Would it be OK to clean it and not add any grease?

Any suggestions on how to clean this much appreciated.


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## coffeechap (Apr 5, 2012)

Clean and regrease, the grease lubricated the return spring in the doser mechanism


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## mokapoka (Jun 20, 2011)

coffeechap said:


> Clean and regrease, the grease lubricated the return spring in the doser mechanism


Thanks. What kind of grease should it be? I never greased anything:dummy:, how should it be applied? What happens if I skip the grease? Will it be just a little stiff or will it become unusable? Sorry for silly questions.


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## dwalsh1 (Mar 3, 2010)

food grade grease...........................maybe


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## marcuswar (Aug 19, 2013)

Maybe "molykote 111" as it's deemed food safe and is what is recommended for lubricating the valves in the E61 brewhead.

Best price I have found is eBay 100g for 7.99; http://www.ebay.co.uk/itm/MOLYKOTE-111-SILICONE-COMPOUND-100-grams-/281656525283?pt=LH_DefaultDomain_3&hash=item41940981e3


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## urbanbumpkin (Jan 30, 2013)

I use molykote111.

If it's just part of the doser, would something like Vaseline be suitable?


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## jeebsy (May 5, 2013)

Would think so, it's not coming into any contact with the coffee


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## CamV6 (Feb 7, 2012)

Dripping


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## mokapoka (Jun 20, 2011)

How can I clean the burr chamber? If I remove the nut in the picture, will it make me able to clean under that plate? Will I ruin something by removing the nut? I have seen some other Major's with cables connected to the doser. Mine doesn't have these cables? Do all Major's have these cables, or have mine been tampered with? Mine is a 2009 manual.


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## marcuswar (Aug 19, 2013)

If you do want to take the lower burr carrier off then please don't be tempted to try levering it off with a screwdriver through the grind chamber exit. It's very easy to distort the carrier slightly. Once the nut id removed you'll probably find the lower carrier still doesn't want to come off. Best method I have found is to simply blast the carrier with a hot air gun (like the ones used for stripping paint) for 10 or 15 seconds and it should expand enough to pop off. Wear gloves though as it will be hot.


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## Dylan (Dec 5, 2011)

Why is it that the carrier expands away from the shaft, and not evenly outward in every direction actually tightening it against the shaft?


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## marcuswar (Aug 19, 2013)

Interesting point Dylan, I don't know the answer but this trick certainly works on Brasilia/Rossi grinder


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## urbanbumpkin (Jan 30, 2013)

Is it because the carrier and shaft are made of different metals and one expands quicker than the other?


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## mokapoka (Jun 20, 2011)

marcuswar said:


> If you do want to take the lower burr carrier off then please don't be tempted to try levering it off with a screwdriver through the grind chamber exit. It's very easy to distort the carrier slightly. Once the nut id removed you'll probably find the lower carrier still doesn't want to come off. Best method I have found is to simply blast the carrier with a hot air gun (like the ones used for stripping paint) for 10 or 15 seconds and it should expand enough to pop off. Wear gloves though as it will be hot.


I actually have a heatgun so will try this. Thank you!

Having a hard time assembling the doser. Something is sticking up from the bottom of the doser at 4 o'clock? What is this, should it be there? It is obstructing the arms.


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## El carajillo (Mar 16, 2013)

The ratio of expansion between aluminium and steel is approximately 12 to 6, hence the reason the heat releases the carrier from the shaft


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## jeebsy (May 5, 2013)

I think what Dylan was asking if why does the internal diameter of the hole not get smaller when it expands causing it get tighter on the shaft?


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## El carajillo (Mar 16, 2013)

mokapoka said:


> I actually have a heatgun so will try this. Thank you!
> 
> Having a hard time assembling the doser. Something is sticking up from the bottom of the doser at 4 o'clock? What is this, should it be there? It is obstructing the arms.
> 
> View attachment 13724


That is a "roll pin", look underneath, I think you will find it prevents a bolt coming undone. Gently tap it down until it is flush with the base.


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## mokapoka (Jun 20, 2011)

El carajillo said:


> That is a "roll pin", look underneath, I think you will find it prevents a bolt coming undone. Gently tap it down until it is flush with the base.


I did look under and seems its just beneath the "counter". The gentle tap is not working. Do I dare to use heavy force?


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## Drewster (Dec 1, 2013)

Dylan said:


> Why is it that the carrier expands away from the shaft, and not evenly outward in every direction actually tightening it against the shaft?





jeebsy said:


> I think what Dylan was asking if why does the internal diameter of the hole not get smaller when it expands causing it get tighter on the shaft?


That'd be physics!

Without getting too technical (not least because it's a long time ago when I studied metallurgy) if you think about the hole as the centre of a ring (rather than a little hole in a big disk) then when the ring heats up and expands... the ring gets bigger.... so the hole gets bigger....

For the hole to get smaller the metal would have to "compress" or "squeeze in" - which is clearly impossible.....


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## marcuswar (Aug 19, 2013)

Thanks for the science class Drewster, makes perfect sense when explained like that.


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## urbanbumpkin (Jan 30, 2013)

Drewster said:


> That'd be physics!
> 
> Without getting too technical (not least because it's a long time ago when I studied metallurgy) if you think about the hole as the centre of a ring (rather than a little hole in a big disk) then when the ring heats up and expands... the ring gets bigger.... so the hole gets bigger....
> 
> For the hole to get smaller the metal would have to "compress" or "squeeze in" - which is clearly impossible.....


Put far better than I ever could


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## El carajillo (Mar 16, 2013)

mokapoka said:


> I did look under and seems its just beneath the "counter". The gentle tap is not working. Do I dare to use heavy force?


You can use more force but support the surrounding metal (from underneath) to prevent bending or cracking the aluminium


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## jeebsy (May 5, 2013)

mokapoka said:


> I did look under and seems its just beneath the "counter". The gentle tap is not working. Do I dare to use heavy force?


Mine required some gentle persuasion to come out. And when I say gentle, i mean violent force


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## mokapoka (Jun 20, 2011)

El carajillo said:


> You can use more force but support the surrounding metal (from underneath) to prevent bending or cracking the aluminium


Thanks for your support. I now got it in enough, not to obstruct the arms but it still sticks up a little. Think I leave it like that since arms now go free.



jeebsy said:


> Mine required some gentle persuasion to come out. And when I say gentle, i mean violent force


I used that gentle persuasion when trying to separate the hopper from the black holder thingy and of course broke the tabs. And I even read in advance that those tabs break easily.


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## Dylan (Dec 5, 2011)

Drewster said:


> That'd be physics!
> 
> Without getting too technical (not least because it's a long time ago when I studied metallurgy) if you think about the hole as the centre of a ring (rather than a little hole in a big disk) then when the ring heats up and expands... the ring gets bigger.... so the hole gets bigger....
> 
> For the hole to get smaller the metal would have to "compress" or "squeeze in" - which is clearly impossible.....


Still doesn't make any sense in my head!

Dont get me wrong, I dont know the first thing about it and I am most certainly not saying you are wrong.

But imagine this. You have one piece of square metal, you heat it and it expands, thus the square is larger in both width and depth.

Now take 4 squares and arrange them so there is a square hole in the center of them, assume they wont get in each others way and apply the same heat and expansion. As they are all getting bigger, the square hole in the middle gets smaller.... or at least it does in my terribly unscientific mind.


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## Dylan (Dec 5, 2011)




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## urbanbumpkin (Jan 30, 2013)

Dylan said:


>


Because it does?

Imagine using a "doubling size" ray on a polo mint. The expanded mint would have a bigger hole in it compared to the original one, rather than the hole remaining the same size or shrinking.

This is based on scientific theory gleamed from "Despicable Me", so you may wish to just go with my opening line.


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## marcuswar (Aug 19, 2013)

If the hole was only a few mm's and you expanded the metal then for it to work like you say the hole would have to actually heal itself at some point.

Or think of a F1 race car were the engine tolerances are so tight that they have to preheat the engine to expand the blocks enough that the pistons can move. If the block expanded in both directions its would actually get tighter.

Or to put it another way, think of it simply as scaling up the size. If you took the image and resized it on a computer the hole would get bigger in proportion to the overall increase in scale.

Isn't science fun .. oh sorry not fun, confusing , yes that the word I meant.. confusing


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## Drewster (Dec 1, 2013)

Dylan said:


> Still doesn't make any sense in my head!
> 
> Dont get me wrong, I dont know the first thing about it and I am most certainly not saying you are wrong.
> 
> ...


OK then using your model....

4 squares.

Lets say they are exactly 10cm along each side at room temp.

Arrange them to leave a square hole ie Squares touching at each corner

Right - How big is the hole?

(Hopefully you can "see" that) Each side is 10cm... it must me right? Cos each of the squares it that big....

Now heat up the squares - lets say they expand by .2cm along each side (I have no idea how much they would expand but it doesn't mater)

OK now arrange the 10.2cm squares (touching at each corner) to leave a square hole....

How big is the hole?

(Hopefully you can "see" that) Each side is 10.2cm... it must me right? Cos each of the squares it that big....

Now (to expand our model)... imagine the four squares are fixed together (say a spot weld at the corners)

Cool them down... 10cm hole....

Warm them up.... 10.2cm hole...

The hole doesn't (indeed cannot) get smaller

QED


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## CamV6 (Feb 7, 2012)

The easiest and simplest and safest way to clean under the lower burr carrier without risking damage by removal is to get a nice fat bit of pipe cleaner in underneath like a chimney sweep. I do this and it works a treat although I use a fat grey teepee brush. I could send you one if you like


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## Dylan (Dec 5, 2011)

Drewster said:


> OK then using your model....
> 
> 4 squares.
> 
> ...


This makes a lot of sense, led me to google along those lines and someone had kindly drawn this diagram, which helps with the explanation.


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## urbanbumpkin (Jan 30, 2013)

Like an expanding polo mint


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