# Stripping and rebuilding a mignon



## coffeechap

Hi folks having just finished stripping, cleaning and rebuilding the lovely little eureka mignon doser version I thought it might help some of you if you are so inclined, if I posted a thread detailing the process and order of stripping the little beast down, once stripped just do everything in reverse for the rebuild this will take a few posts to get all the photos in so bear with me. My start point is showing the machine immaculate after the rebuild and I will work back from that point









Ok first you have to remove the hopper from the grinder which doesn't really need an explaination then remove the two flat head screws at the top of the doser chamber see below.









Next you need to remove the three screws from the top plate to get the burr carrier assembly off









Ok what you will see now is the bottom burr assembly this is the part that moves up an down to adjust the fineness of the grind, you will need to remove the nut in the middle of the burrs, it turns clockwise and you have to use another screw driver to prevent the burrs from spinning see below









The nut requires an 11mm bit to remove it


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## coffeechap

Once the nut is removed, gently prise out the burr carrier assembly using a flat head screw driver then you will have cleared the burr assembly chamber, this will be full of coffee all you need to do is Hoover it out and wipe with a clean cloth to remove any residue, stubborn residue can be removed with a mild degreasant but make sure you wipe clean again.

















Ok now you need to remove the base of the unit by unscrewing the four cross head screws holding the base in place, this will allow you to move on to remove the motor, it is important that you do things in this order as it allows you to get to the nuts retaining the doser chamber on the main body of the grinder.









Once removed you will expose the base of the motor and will notice coffee grinds, just Hoover them up and wipe clear









ok onto the next thread which will be switch and motor removal


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## coffeechap

Ok so now gently prise out the switch from its housing, it is held in place by some small lugs, it should come out fairly easy. What I tend to do when it is removed, as with any adjustments to electrical wiring is to take a photo of the wiring to make sure I have a reference point to refer back to should I get distracted.

























Please notice that once i removed the cables to get the switch out, i reattached them so that the swich and motor assembly remained one unit, this again helps as it keeps all the cables in place. Once the switch is removed, now remove the portafilter holder on the front of the main body, this is done by unscrewing the large cross head screw retaining the holder.









Remove the holder and now turn the grinder back up the right way and remove the grind adjustment knob by completely unscrewing it turning it anticlockwise


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## coffeechap

Right now onto removing the motor assembly. With the adjustment knob now removed, unscrew the three retaining cross head screws in the burr assembly unit, do this slowly as when the last one is removed the motor will drop out of the bottom of the main body, notice that the grind ajustment knob has been removed.

























Once the motor is removed it will be seperate from the main body and still be attached to the electrics in the base, take care to keep the washer attached to the top of the grind adjustment rod.









You will now be able to access the nuts that retain the hopper on the main body









This body has already been cleaned, in fact once completely diss assembled, all of the components are very easy to clean with warm water and a mild detergent, remember to rinse and remove any detergent once clean.


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## coffeechap

Right last thing to do is to strip down the doser chamber ready for cleaning. Once the bolts have been removed the doser chamber will just gently pull off the main body, leaving a completely bare body and seperate chamber, but first remove the metal plate at the base of the doser by gently unscrewing the two tiny cross head screws.









View attachment 2567


Remove the doser using an 8 mm spanner on the retaining nuts inside the main body,the clear plastic viewing chamber at the top will come apart, all you have to do now is unscrew the tiny cross head screw in the centre of the portion divider and remove the top part.

View attachment 2569


Finally the grinder will be completely diss assembled, clean all the parts and dry them thoroughly then re assemble following this guide in reverse

View attachment 2568


Hopefully it should end up looking lovely like this

View attachment 2570


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## haz_pro

Very nice, thanks for making this thread. Doesn't seem too hard so I may try this soon.


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## glevum

Excellent Dave


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## bubbajvegas

Great instructional mate,next up the mazzer series?looool


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## Roopster

Thank you - amazing!


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## reneb

Many thanks Dave, hugely appreciate this thread. I was wondering how you take off the bottom burrs. I'm sure the clockwise thread thing would have thrown me for a while!


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## japes

Great timing... I literally picked up a used Mignon doser yesterday and was just thinking to myself whether I could find a rebuild guide somewhere on line! Thanks Dave.


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## haz_pro

japes said:


> Great timing... I literally picked up a used Mignon doser yesterday and was just thinking to myself whether I could find a rebuild guide somewhere on line! Thanks Dave.


Did you purchase it from someone called Peter in Ealing? I purchased one yesterday and the day before so did rooster (same bloke).


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## Big Tony

Excellent... Cheers Dave.

Where are these dosers coming from? Link?


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## japes

haz_pro said:


> Did you purchase it from someone called Peter in Ealing? I purchased one yesterday and the day before so did rooster (same bloke).


That's the chap... have you open yours up yet? Haven't checked to see what condition the burrs are in mine yet. The bigger Eureka he also had looked like a nice machine.


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## Roopster

Big Tony said:


> Excellent... Cheers Dave.
> 
> Where are these dosers coming from? Link?


http://www.ebay.co.uk/itm/140975217676?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

I emailed him through ebay. So that makes 4 of these he had then (so far!) Mine, Japes, Haz Pro & Coffeechap.

I'm missing the hopper lid and my doser arm is cream plastic (rather than black) so might be a replacement, but the burrs seem sharp (I'm no expert though...) I wish I'd waited for this thread before cleaning mine - would have saved me a lot of time!! The bigger MDL I also bought was a bit more complicated, so I did everything except take the motor out...


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## 4085

Would be interesting to know if you guys all paid the same dollar! You going to share this info with us then?


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## Roopster

dfk41 said:


> Would be interesting to know if you guys all paid the same dollar! You going to share this info with us then?


Haha!! I'll tell if everyone else will!


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## japes

Well... I paid <cough> 100 GN...</cough>


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## painty

Very useful guide Coffeechap



japes said:


> Well... I paid <cough> 100 GN...</cough>


GN ?


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## japes

painty said:


> GN ?


*G*old *N* ugget ... £100.


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## origmarm

Many thanks Coffeechap. May well come in useful when I come to giving mine (doserless) a good clean!


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## haz_pro

I also paid 100, tried to knock him down but wouldn't move a sausage. I reckon rooster paid some less due to buying two 

I think we all done well either way.


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## coffeechap

Rooster paid £300 for them both, which was a steal.


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## Roopster

Almost Coffechap - managed to knock £20 off for buying two!


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## coffeechap

Sell the little one keep the beauty


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## shrink

Looks very much the same kind of construction I saw on the MDX.

I had that in just about as many bits across the kitchen to clean it out properly.


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## haz_pro

Is it possible to make the grind setting to close do that the burrs hit each other? I don't want to do this if you can lol; so wondering just so I can avoid it.


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## shrink

Yep, it's not only possible, it's very easy to do. Especially on these, as the adjustment is quite large on the knob.

When I dialled in, I started by running the motor and carefully adjusting till the very first hint of burr on burr. Then very very quickly dialling it back a notch. From here it's generally easier to adjust for espresso which is usually in the last part of the burrs useful range.


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## reneb

Yes, I'd follow shrinks advice. Adjust the burrs with no beans very slowly finer until you just hear the 'chirrup' of the burrs touching, then immediately back off a fraction - you now have a zero point as it were and apparently this won't damage the burrs as there is an outer run off section that touches first. Now wind out about 1.5 numbers coarser and use that as your starting point, adjusting accordingly after each test shot.


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## haz_pro

Hey all,

Followed advice above but it didn't go too well.

I thought I heard the burrs touching but when I ran some beans through it the grounds were very course. I know it can grind finer as I done it in the past couple of days making much finer grounds.

Will try again soon...

On another note, I went to strip it down today but couldn't get the bolt off which holds the bottom burr assembly on. Not sure what I am going to do yet, except for get a huge extension to use.


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## shrink

Here's another idea... Take out the hopper... Unplug the grinder, and turn the burrs by hand using the spindle.

Then keep adjusting fine until you can't turn by hand any more. That will be the touching point.

Often on these grinders, little bits of coffee get stuck on top of the sweepers inside the chamber, and its those that you're hearing when you adjust it with the motor on. I came across the same problem on my MDX which used the same adjustment system, when I thought the burrs were touching, it was miles away,

So I took out the hopper and turned it by hand, and adjusted until it was impossible to turn by hand. And called that my zero point, also less chance of damaging the burrs.


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## haz_pro

Brilliant idea, thank you buddy.









EDIT: Okay, so I just done what you said and it works great. I did notice that when loosening the burrs it got to a point where the burrs only touched once per a rotation. Is this caused by damage to the burrs or something else?

I loosened the burrs slightly more and all is well.


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## coffeechap

it might just be that one of the screws holding the burrs in place id slightly looser than the others, remove the burrs then clean out all the coffee on them and the chamber (unless you have already done this) now refit the burrs ensuring that all te screws are the same tightness.


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## haz_pro

Considering how tight all of the other fixings are I would be surprise. I will give that a go though when I get the burrs off. I need to get more leverage for the 11mm clockwise nut.


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## coffeechap

You are definitely turning the centre nut clockwise i.e. not the way you would think to turn it?


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## haz_pro

100%, I remember reading it in your write up and it really stuck out to me. I am going to use my socket set next time with a bigger extension. Probably try on Monday which should be when my classic comes too, woo.


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## Roopster

I couldn't get the bottom burr assembly out either. I undid the three screws holding the burr to this though and got the bottom burr out on its own to clean up as much as I could.

One of the three screw holes seems to be damaged so that the screw just spins round (I've tried swapping the screws round to check and its definitely the hole rather than the screw.) Can this cause problems as mentioned above? Any thought of how to fix this? I'm scared to try and make a slightly larger hole in the assembly!


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## El carajillo

I do not know this machine but having engineering knowledge and from looking at strip down photos on forum I would say that the thread in the burr carrier has been stripped.

Your options are 1. New burr carrier 2. Drill out burr carrier and re tap to next thread size up ( you may have difficulty enlarging hole in burr because it is hardened)

3.A small local engineering company could insert a "HELICOIL" this is a hardened spring that returns the thread to its original size

Hope this helps.


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## Roopster

Thank you el carajillo - I think option 1 might be the best bet!


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## haz_pro

Well, I done what you done rooster and just removed the burr from the burr carrier and then hoovered. Yes this isn't quite as in depth a clean as coffechap but it will do for now.


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## coffeechap

Just do what works for you guys, the strip down can be taken as little or as far as you want, and if you come across another method that works then great...


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## haz_pro

I would like to do it as far as you, but don't have a tool with enough leverage currently. I will have another go in the week though as I would really like to clean each individual part.

Rather than using a screwdriver, would winding the burrs tight enough so that they touch (and thus can't move), risk damaging them? This may be easier for me, but I would only do it if it doesn't risk the burrs being damaged.


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## japes

haz_pro said:


> I would like to do it as far as you, but don't have a tool with enough leverage currently. I will have another go in the week though as I would really like to clean each individual part.
> 
> Rather than using a screwdriver, would winding the burrs tight enough so that they touch (and thus can't move), risk damaging them? This may be easier for me, but I would only do it if it doesn't risk the burrs being damaged.


haz_pro, just finished stripping, cleaning and rebuilding mine. Have to say I don't think it had been cleaned in a while... lots of residue built up on underside of burr carrier. I have to say mine was awkward to get out- in the end, I removed the burr, lay a bit of thin webbing on top of the burr carrier, screwed the burr back down on top to sandwich the webbing, and then pulled up on the latter. Did the trick.


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## coffeechap

well done japes, hope you enjoy that lovely little grinder, at an astonishingly good price


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## japes

Thanks coffeechap. Have gone from an Iberital MC2, to owning the Mignon and Shrink's NS MDX in a week. Happy days.


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## coffeechap

if you can mod that mdx you are going to get better results


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## haz_pro

japes said:


> haz_pro, just finished stripping, cleaning and rebuilding mine. Have to say I don't think it had been cleaned in a while... lots of residue built up on underside of burr carrier. I have to say mine was awkward to get out- in the end, I removed the burr, lay a bit of thin webbing on top of the burr carrier, screwed the burr back down on top to sandwich the webbing, and then pulled up on the latter. Did the trick.


Hey mate, was this after reviving the nut from the burr carrier? My problem is not being able to get this bolt lose, which means I can't pull it off.


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## haz_pro

Sorry I meant removing the nut.


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## origmarm

Ok so I partially disassembled mine this weekend just to remove the burrs and give a good clean. I have to say it was pretty clean despite some good use. I put this down to vacuuming every couple of weeks when I brush out.


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## SadikYP

Thank you very much for this thread.

I will be rebuilding my mignon this weekend

Also can the doser be removed & configured in a doserless setup?

& where can I get a replacement hopper lid?


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## rodabod

This thread needs more photos.


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## SadikYP

Thank you so much for this guide.

Helped me this morning.

My Mignon is now clean & almost like new.










Sent from my iPhone using Tapatalk 2


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## glevum

Well done, an excellent little grinder! enjoyed this thread ....thanks Dave(coffeechap)


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## Wombat

I've just created a new thread due to by Mignon locking up after a year of use roughly twice daily - after taking the top off and vacuuming out the chamber I suspect hardened grinds sitting down the side of the lower burr are responsible.

My question therefore, how often would you recommend a) simple removal of the upper burr for a brush and vacuum and b) removal of the burr assembly for a full clean?

Thanks for this thread and thanks for any suggestions,

Will


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## Stevo

Fab thread - guys thanks for all the effort!


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## ernest563

I assume that if the motor stator is firmly mounted with three bolts, the rotor is the one that moves up and down, correct?


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