G-IOTA / DF64 espresso grinder - Page 119

Grinders are one of the keys to exceptional espresso. Discuss them here.
HalfCaff

#1181: Post by HalfCaff »

Yeah, I think I'll do the same (tinker with declumper). I'm a design engineer by education and 40 years of product design experience, so I'm always looking for *why* products behave the way they do. A grinder is a very simple machine. If the burrs are well designed, stable, and parallel, and the beans make only one pass between them, it shouldn't matter if they're spun by a $450 Chinese grinder or a $3000 Italian grinder.

It seems reasonable to guess that the trouble I'm having is caused by regrinding, and it also seems reasonable to assume that the anti-clumping thingie is responsible for some of that regrinding. I've also ordered an anti-popcorn gizmo from an Etsy seller to cover the idea that popcorning leads to nonuniform grinding performance.

If tinkering with the anti-clumping and anti-popcorn measures don't lead to a more uniform puck, then I have to start wondering about burr stability. Maybe those burr carrier springs are allowing the fixed burr to bounce up and down during grinding?

heytchap

#1182: Post by heytchap »

Reminder that removing the duclumper or interacting with it changes your config - the bottom screws control the spacing and balance of the bottom burr which does not go back exactly the same way without considerable effort.

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Brewzologist
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#1183: Post by Brewzologist »

heytchap wrote: Reminder that removing the duclumper or interacting with it changes your config - the bottom screws control the spacing and balance of the bottom burr which does not go back exactly the same way without considerable effort.
Agree the screws on the base can affect the bottom burr. But can you explain the considerable effort needed to get it back in balance? I didn't experience any challenge there, unless I'm still unaware it's not right?!?
HalfCaff wrote: If tinkering with the anti-clumping and anti-popcorn measures don't lead to a more uniform puck, then I have to start wondering about burr stability. Maybe those burr carrier springs are allowing the fixed burr to bounce up and down during grinding?
Conventional wisdom on most grinders with springs seems to be that during grinding it's the beans which keep the burrs separated, not the springs.

mikelipino

#1184: Post by mikelipino »

Also puck uniformity might be the problem. Depending if your machine preinfuses and how it delivers pressure, a tightly uniform grind can be difficult to prevent from channeling. Fines are much maligned, but can be the glue that holds the puck together and allow for even flow. It's why Option-O worked with SSP to tweak the Unimodal V1 burrs to allow slightly more fines and create the Unimodal V2 burrs (also called multi-purpose because they became easier to use with espresso). I'd say with the mods, also try things that mitigate channeling like solid puck prep, preinfuse, ramp up pressure, and ramp down pressure to preserve flow rate as the puck degrades.

And I'm with Steve, the springs mostly just keep the burrs apart against gravity. While grinding, the beans push the burrs apart and the collar mating surface pushes back and keeps the burrs parallel.

heytchap

#1185: Post by heytchap »

Brewzologist wrote:Agree the screws on the base can affect the bottom burr. But can you explain the considerable effort needed to get it back in balance? I didn't experience any challenge there, unless I'm still unaware it's not right?!?
Unless you got the torque perfectly balanced, there's a good chance your bottom burr is lopsided and sitting at an angle.

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Brewzologist
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#1186: Post by Brewzologist »

But if I did a marker test and it was clean then I should be ok. Would think so!? How did you determine this happens? Would like to know how to test it.

heytchap

#1187: Post by heytchap »

Go back to pages 116 and 117

Kran

#1188: Post by Kran »

Brewzologist wrote:But if I did a marker test and it was clean then I should be ok. Would think so!? How did you determine this happens? Would like to know how to test it.
I feel the same way about this, maybe I'm also missing something. You align by doing the marker test and shimming. You take the base off to play around and according to some posts on here (I haven't done it so I can't speak to how off it will get) you can affect lower burr position when you put it back together. So then you do the marker test again and if it's off you re-shim.

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Brewzologist
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#1189: Post by Brewzologist »

heytchap wrote:Go back to pages 116 and 117
Sorry, don't see anything about lopsided burr tests there. I posted in those same pages where even the motor in my Niche basically floats on rubber mounts underneath the burr chamber. Perhaps this design is not uncommon which is why some grinders need shimming of the lower burrs.

As others have recommended, I apply light torque to the base screws; nothing fancy. This and a little shimming of burrs has made the DF64 rock solid for me. Given the size of the bearings in the DF64 it doesn't surprise me. But yes, if you mess with the base it may throw your alignment off, I just haven't experienced it.

That said I do have the stand-off's on order and will test to see what impact they have. As I also theorized in those pages you mention, it may well be that the design of the DF64 (and Niche?) relies on downward tension to keep the bottom burr seated. This isn't optimal given the DF64 doesn't use thrust bearings, but for the money it works quite well.

michang5

#1190: Post by michang5 »

Half Caff, it's taken me nearly five months, but I've finally gotten my DF64 (with stock burrs) to produce shots as consistent and non-channeling as my Niche with the following mods/steps:

1) Grinding directly into the portafilter improved things a ton. Getting this custom machined collar ( ) allowed me to do so with minimal mess without RDT-ing.

2) WDT-ing with a proper tool (I use one made with four 0.3mm acupuncture needles) and tamping with the Normcore V4 leveling tamper cut squirting and misting significantly.

3) Modding to the Mythos declumper - and later removing the declumper entirely, leaving only a spacer - was key to minimizing rentention, regrinding and fines. I was happy with the Mythos until one recent bag of beans gave me trouble and I removed the Mythos as a test with no adverse effects other than a 5% increase in static. Again, the custom collar is critical to running a modded or no declumper without RDT-ing.

4) Lastly, a shift in my bellowing has resulted in much more consistent shot times. I used to very gently bellow during the grind. I've learned that that was a mistake. I now only bellow at the end. With other variables controlled, my shot times are as consistent as with the Niche.