# DF64 shot consistency mystery



## Fat_Ed (May 6, 2020)

Posting this here as a last ditch attempt at regaining my sanity. 

I recently purchased a DF64 grinder to replace my Sage Pro. I have a Gaggia Classic (2004) that's had all the usual mods, and I’ve a reasonable grasp of puck prep.

Here’s the problem though. When I switch on the machine for my daily espresso, since getting the DF64, *every shot runs faster than the last without changing the grind setting*. 

The first shot practically chokes the machine. The 2nd is halfway decent. The third is a bit fast and the fourth a spritzy mess. Every. Single. Time. 

Typical pattern:

Shot 1 — 18.1g in grinder 18.05g out. 36g in the cup @ 40-45s
Shot 2 — 18.1g in grinder 18.1g out. 36g in the cup @ 27-30s
Shot 3 — 18.0g in grinder 18.0g out. 36g in the cup @ 23-25s

Some things I've ruled out...

*My puck prep*
I'm by no means a pro, but I'm fairly confident this is not the issue. Every time I WDT, I give it a knock or two to settle it and a then use the Normcore V4 (spring-loaded, self-levelling) to tamp. And that the pattern repeats itself so much... I don't think this is the case.​
*My beans*
Same pattern on multiple beans.​
*My Gaggia*
I've had the machine for 2 years now and never had anything like this. But regardless, I have experimented by grinding out a dose, putting it aside, grinding a second dose and pulling that, then pulling the 1st dose. They maintain the pattern of timing. I've also started pulling a mugful of water through the machine to prime it. Repeated a few times and again, no change.​
*Retention*
I'm weighing what goes in and comes out and beside a 0.05gram lost here and there, it doesn't seem like that's the issue... I also changed out the stock declumper on the DF64 for a 3D printed mod.​
*Burr alignment*
I've done the marker test and shimmed with foil to get the burrs probably 90% aligned.​

So basically I'm fresh out of ideas... I think I'm going to just return the grinder, but jesus if I wouldn't love to know just what the hell was going on! All I can think is something about the amount of fines being produced, but I have no idea why that would change over subsequent grinds...?

Help me. Pls.


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## mdvineng (10 mo ago)

Possibly something is moving inside the grinder


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## Alfieboy (Dec 26, 2018)

What number do you grind on? I know it varies but for an idea


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## mdvineng (10 mo ago)

Compare the grind size output from the three shots to see if it is the grinder moving out of spec.


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## Fat_Ed (May 6, 2020)

Uncletits said:


> What number do you grind on? I know it varies but for an idea


Around 11. I re-zeroed it based of the chirping point, which was a good 5-8 marks further round than default.


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## Fat_Ed (May 6, 2020)

mdvineng said:


> Compare the grind size output from the three shots to see if it is the grinder moving out of spec.


I’ll have a go at this tomorrow.


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## newdent (Feb 20, 2021)

How recent was the purchase? Burrs can be a bit fickle until seasoned. Your shot variance isn't massive. You may also be discovering just how user friendly conical burrs are over flats. 

Things showing faster after previous shots can happen as componentry warns up. Do you have temperature regulation on your Gaggia?


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## Fat_Ed (May 6, 2020)

newdent said:


> How recent was the purchase? Burrs can be a bit fickle until seasoned. Your shot variance isn't massive. You may also be discovering just how user friendly conical burrs are over flats.
> 
> Things showing faster after previous shots can happen as componentry warns up. Do you have temperature regulation on your Gaggia?


It’s a few weeks old. Probably had a KG through it at least, so yeah could be a seasoning thing I suppose. Still seems weird that it’s so consistent a pattern?

I have a fairly well tuned PID on the Gaggia, and flushing a good 100ml of water through (and letting temp recover) before pulling first shot.


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## newdent (Feb 20, 2021)

Fat_Ed said:


> It’s a few weeks old. Probably had a KG through it at least, so yeah could be a seasoning thing I suppose. Still seems weird that it’s so consistent a pattern?
> 
> I have a fairly well tuned PID on the Gaggia, and flushing a good 100ml of water through (and letting temp recover) before pulling first shot.


Machine sounds good then. You heat your PF in the machine?

I was having these sorts of issues after buying a new grinder, it was a eureka mignon, almost drive me insane. Unlike yours the was no consistency. I asked about it on here and a cynical few accused me of buyers remorse.

Returned the grinder and when inspected by the supplier, they said something had come loose internally but they were very reluctant to accept the return initially. It sounds like you're competent at making coffee, I'd get the supplier to take a look at it.


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## Fat_Ed (May 6, 2020)

*Update*

Just done my afternoon brew. As usual, flushed the machine through before running. Puck prep for each shot was the same, grind size was the same. I was tinkering with the grinder yesterday so was a bit off the grind setting I was on the last few days so everything ran faster, but the overall pattern was the same. Just meant I had to steam some milk to take the edge off!! 

I've added photos of the grinds — I can't see anything different, but then I don't really know what I'm looking for 😂









*Shot 1: *17.8g — 35.9g in cup @ 23s
Grinds 👇















*Shot 2: *17.8g — 36.5g in cup @ 17s
Grinds 👇















*Shot 3: *17.8g — 37g in cup @ 14s
Grinds 👇


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## newdent (Feb 20, 2021)

If you've got access to a printer, maybe try printing off a PDF brewler (Google it) and attempt to assess the grind size in microns. Much harder in the espresso range though. 

It's really hard to comment on the grinds without any frame of reference, though it's say perhaps it looks quite finely ground rather than the opposite. Do you have a bottomless PF, how does the shot pull? Watching a clip of the shot would help diagnose.


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## mdvineng (10 mo ago)

You're looking at the size of the grind particles for differences between shots. Feel it between your fingers.


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## newdent (Feb 20, 2021)

My starting point if I've lost my calibration for some reason is if I squeeze the grinds together in my palm, they should clump and hold a shape but fracture very easily when touched. If it holds its shape and you can push the large clumps around and they don't fracture then it's likely far too fine. 

A bottomless shot will very clearly let you know where you are from there. Shot time alone is pretty useless as you could have channels.


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