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Robbie

Super Jolly Inconsistent Grind Size

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Hi guys,

I recently picked up a Mazzer Super Jolly from the forum, it seems to be in good working order (to my untrained eyes...), runs smoothly and I've already vastly improved the quality of shots I'm pulling on my Gaggia Cubika.

I drilled out the portafilter so its bottomless so I can get a better look at the shot flow, and i seem to be getting varying areas of no/little flow. every shot there will be a spot with no flow, but it moves every time. eventually after ~20-25 seconds there is even flow through the puck towards the end of the shot.

I started inspecting the grinds as my tamping didnt seem to be toooo terrible and i noticed quite a large amount of inconsistency in sizes. some patches where you can see individual grains amongst areas where its too fine to see that detail. This would definitely explain some channeling.

I was wondering if theres something wrong with the grinder that I need to adjust/repair? or if its common to get a grind size distribution and I just need to mix/'stir' the grinds before tamping? (as the grinder has the funnel mod)

Thanks!

Robbie

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Without more precise info, it's impossible to say whether you have an issue.

All coffee grinders make a grind size distribution, some larger particles might be as much as 4x larger than the average size (around a mm for the largest?), under the average it will go all the way down to fine powder.


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13 minutes ago, MWJB said:

Without more precise info, it's impossible to say whether you have an issue.

All coffee grinders make a grind size distribution, some larger particles might be as much as 4x larger than the average size (around a mm for the largest?), under the average it will go all the way down to fine powder.

What sort of info do you need? 

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In what condition are the burrs? 


GS3 MP, Ceado E92 and E37s, Feldgrind. Niche.

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Isn't it possible to align SJ burrs with foil shims to get better consistency?


Laissez les bons temps rouler

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2 hours ago, Robbie said:

What sort of info do you need? 

What % pass through 250um & 500um ASTM sieves, or 300um & 600um ASTM sieves (about £80 a sieve plus VAT & delivery).

Realistic answer is to double check all the easy/obvious things (are the burrs worn/sharp, are you dosing & hitting ratios carefully, not grinding into the PF) before you start worrying about grind consistency.

Even grinders with wide distributions/coarser grinds, by design, can make tasty drinks if you play to their strengths.

Edited by MWJB

“Coffee evokes the most insane reactions in people”, Rene Redzepi.

 

https://markwjburness.wordpress.com/

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No.

You can't align the top/upper burr.

Mazzer has a retarded system for the upper bur (they changed this for the newer models-2019) with a lot of play/wooble you can feel by hand (100-200microns). There is no point in sweating alignment on such horrible design.

I always call silly people who buy top SSP burrs to put it inside mazzers, what's the point of a hyper tolerance made burr when you use it in a Mazzer? or a Ceado?

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No.
You can't align the top/upper burr.
Mazzer has a retarded system for the upper bur (they changed this for the newer models-2019) with a lot of play/wooble you can feel by hand (100-200microns). There is no point in sweating alignment on such horrible design.
I always call silly people who buy top SSP burrs to put it inside mazzers, what's the point of a hyper tolerance made burr when you use it in a Mazzer? or a Ceado?
So what grinders would you recommend for ssp burrs?

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Sage Duo Temp - La Cimbali 6/S A 64mm flat burr + numerous projects: Sunbeam, Ascaso, Gaggia

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Remove  adjuster and top burr carrier, remove both burrs and examine closely, particularly the outer edges where the particle grinding is done.  Look at the V shaped edges and look for chips , nicks or rounded edges (they will show some wear but any excessive wear means replacement burrs).

Thoroughly clean chamber and re fix burr's ( the bottom burr can be centered by placing 1 mm plastic strips between the wiper arms and the burr) (plastic window packer or similar.  Centre top burr in carrier as accurately as possible. Clean out holes where the springs fit and replace them.   Wind down the adjuster until the burr's just start to touch while rotating by hand ( A 1/2 " socket helps with this).  Is it just touching in one place ? or more or is it constant ? If on one side and too much, this can be partially rectified by inserting ' shim steel' on the low side between the burr and carrier. ( use of a TDI gauge helps for checking run-out amount)

This will bring the two burr's parallel with one another horizontally  although they may float slightly in the vertical alignment due to slack manufacturing tolerances.

If unsure about the wear on the burr's , a close up photo will get someone to give advice.

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2 hours ago, Zwanger said:

No.

You can't align the top/upper burr.

Mazzer has a retarded system for the upper bur (they changed this for the newer models-2019) with a lot of play/wooble you can feel by hand (100-200microns). There is no point in sweating alignment on such horrible design.

I always call silly people who buy top SSP burrs to put it inside mazzers, what's the point of a hyper tolerance made burr when you use it in a Mazzer? or a Ceado?

Unless it is in the ZM, which is how jazzers should be built. You can make sure that the burrs are at least central to the carrier even in the stock carriers 

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AKA Toffee chips

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To the OP are you single dosing the grinder?


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2 hours ago, MWJB said:

Realistic answer is to double check all the easy/obvious things (are the burrs worn/sharp, are you dosing & hitting ratios carefully, not grinding into the PF) before you start worrying about grind consistency.

Burrs aren't razor sharp but far from worn out. Dosing and ratios are very consistent, but I do grind right into the PF - is that a problem? What should I be doing?

@El carajilloc

Thanks - this is a lot of good info most of which is new to me! I'll have a go at this and see what I find. TDI gauge?

I'll take some pics of the burrs in any case for some expert opinions!

 

@coffeechap yep I'm single dosing - another mistake?

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Not a mistake but if you want a much more even distribution try the  shake and stir method and report back.

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AKA Toffee chips

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They look fine

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AKA Toffee chips

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Robbie, take a look at the grinder forum, third item down 2014 . it shows a DTI gauge and there is further information.

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A deep clean up taking the burrs out, using a toothbrush or a medium brush, vacuum clean everything, be sure to clean the upper burr holder thread, then do the market method for the static burr. This will increase consistency, but you still need to do WDT after single dosing.

Using the grinder with a bed of beans or a weight (tamper) on top of the beans will 100% help obtain a more uniform grind from start to finish of the dose.

 

 

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3 minutes ago, Zwanger said:

A deep clean up taking the burrs out, using a toothbrush or a medium brush, vacuum clean everything, be sure to clean the upper burr holder thread, then do the market method for the static burr. This will increase consistency, but you still need to do WDT after single dosing.

Using the grinder with a bed of beans or a weight (tamper) on top of the beans will 100% help obtain a more uniform grind from start to finish of the dose.

 

 

Unfortunately he is single dosing the grinder, completely agree that running it with weight of beans will markedly increase the grind consistency


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I already was in that stage 3 years ago, it works better with beans into a column (in my case a painted PVC draining pipe), this offers a more weight to press on the beans that are pushed inside the burrs than with a hopper.  You would need to use a less quantity of beans to obtain the same force.

 

 

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On 10/09/2019 at 19:49, El carajillo said:

Thoroughly clean chamber and re fix burr's ( the bottom burr can be centered by placing 1 mm plastic strips between the wiper arms and the burr) (plastic window packer or similar.  Centre top burr in carrier as accurately as possible. Clean out holes where the springs fit and replace them.   Wind down the adjuster until the burr's just start to touch while rotating by hand ( A 1/2 " socket helps with this).  Is it just touching in one place ? or more or is it constant ? If on one side and too much, this can be partially rectified by inserting ' shim steel' on the low side between the burr and carrier. ( use of a TDI gauge helps for checking run-out amount)

This will bring the two burr's parallel with one another horizontally  although they may float slightly in the vertical alignment due to slack manufacturing tolerances.

Went for this yesterday and found the horizontal alignment to be quite far off. Turning with a socket by hand, i found one point to touch before the rest of the burr, to the point that while slowly adjusting the top carrier tighter, it jammed shut at the first touch point before there were any other points of contact in the rotation. so i guess some leveling of the bottom burr is reqd

 

that being said, i went with the WDT and got no signs of channelling in the shot and had to adjust grind finer to maintain a shot time of 28s

On 10/09/2019 at 21:57, coffeechap said:

Unfortunately he is single dosing the grinder, completely agree that running it with weight of beans will markedly increase the grind consistency

I mean, if this is going to make a big difference then I can certainly do it! will storing the beans in the (clear plastic) hopper cause them to go stale significantly faster than sitting in the tin that they currently live in?

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If you cannot find shim steel , try cigarette papers ,folded if necassary.

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You can use aluminum foil for the food industry. The cheap normal thin one has 6 microns thickness.  But you need to make sure  you clean the grinder really good.

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