Hey guys,

Recently I have found that I can't seem to get my grind fine enough when dialling in lighter roasts.

In the past I've had no problem getting decent pours from light roasts (not crazy light, but fairly light beans from La Cabra and Wendelboe as well as some locals such as Luna) but recently I've found that even with lighter medium roasts I am ending up right at my zero point on the grinder (verified) and still in '15 second espresso' territory.

I've up-dosed various amounts up to 19.5g (18g VST basket) which slows things a little but it's still a very fast pour, almost like an under rested gassy coffee and the taste is highly under extracted (obviously) and I'm not a fan of using dose this way when dialling in.

Initially I blamed the beans for this, as the coffee was well rested and everything else was normal, but this has happened now for several bags from several different roasters - same result, I'm right at the very bottom of the grinder's range and nowhere near where I want to be, with no further adjustment I can make other than going up to my 21g basket and updosing even more which doesn't seem like a great solution.

I'm now suspecting the grinder (Fiorenzato F4 Nano V2) is the issue. I took it apart to clean it and inspect things and noticed some weird wear patterns on the floating upper burr carrier (pics below)

There's always been some play in the floating upper burr carrier, could this have developed into a mis-alignment which is now causing weird particle size distribution and causing the symptoms above?

Anybody have any idea what else could be causing this? Is the grinder thing a red herring? Is there something obvious I'm doing wrong here?

E61 HX machine
VST baskets
Grinder is less than a year old, stock burrs, ~50lbs ground.

Thanks in advance!

Pete.

Yeah, that sure doesn't look right in that grinder. I don't know the particular grinder you're using, but that really looks like something mechanical has failed.

Yes, a significant misalignment would cause bad grinds and the problems you're running into.

If you are already sub zero to pull a proper shot, then the chances are pretty good that the cutting parts are not running parallel.
The bigger the gap between zero and your grind setting, the better the parallelism.

padollman wrote:.... I am ending up right at my zero point on the grinder (verified) and still in '15 second espresso' territory.

Hi Pete,

Can you elaborate on how you verified the zero point?

It sounds to me that either your grinder's alignment is not great to begin with, or, there's a physical limiter stopping you from reaching the true zero point.

It looks like maybe one of the springs is missing or broken. That would cause the burr carrier to lean toward the missing spring side and bind.
It also looks like the adjustment ring is binding on the burr collar. There are scratches on it that makes me think that it is binding there too.

Can you elaborate on how you verified the zero point?

I'm pretty sure I have zero correct - after each time I clean and re-assemble the grinder I wind the adjustment all the way down (motor running) until I hear burrs touch, I mark this point on the adjustment ring and use it as a reference point for grind adjustments - am I missing something?

All the springs are present and correct, I'm considering adding some food safe lubricant to the areas the collar that seem to be binding and hope that helps it to be free enough to self level / centre (which I assume is how this design was intended to work?)

Doesn't seem like a great piece of mechanical design IMO!

I have the same grinder and I have no problem with light roasts in an 18g vst basket, so it does sound like there is something out of whack. I do have to back out the screw in the collar which limits how far to the right you can turn it, but I'm still not hitting zero.