Today I did a pretty good deep cleaning of the Mythos and I do not feel that its grind adjustment is accurate since then. Been trying to diagnose choked shots and feeling that the grinders inaccurate grind setting is to blame.

I tried grinding a handful of different 8g batches of the same bean and across various settings (3, 4.5, 7, 10, >10) and all the appeared to be roughly the same regardless of the setting. I am able to find exploded parts sheets but am coming up short on a proper instruction for calibration. FWIW I was getting choked shots before I cleaned the burrs today, but the problem persists (if not worsened) since.

http://www.nuovadistribution.com/images ... lowRes.pdf

If this is your models manual it's on page 20, or sooner on page 8 if your Italian is any good

Marcelnl wrote:http://www.nuovadistribution.com/images ... lowRes.pdf

If this is your models manual it's on page 20, or sooner on page 8 if your Italian is any good

Ah-ha - good eye! I had tried searching the PDF for key words but they're clearly calling the burrs "grinders" and not using the terminology I had in mind. As the PDF says:

Grinding fineness is factory set, with the grinders first adjusted so that they touch each other (0) and then moving the grinders so that they are at a distance to provide an average grinding fineness for espresso coffee. Grinders with re-settable adjustment knob can be set to zero at an established grinding point by holding the top part of the knob in position and using the ring nut on the base of the knob itself. Caution: grinding fineness adjustment needs to be performed gradually, grinding a little coffee each time that the knob is turned by two numbers (notches). The machine may seize up if the knob is moved by one turn while the motor is switched off.

I am a bit confused as I do not see the re-set table adjustment knob they reference. My grinder is a 2011 model but when I reference newer models, even 2013+, the adjustment knob and surrounding area looks the same as mine. My knob is also one single whole piece, so holding the base and wishing to turn the top is fruitless. Perhaps the knob looks the same but is a 2 piece design on newer units. I have inquired with NS USA and will update the thread with any solution I may find. I have verified the zero point with my burrs is at (or just a hair under) zero on the dial face. Backing off to my usual ~4 or even 5 on the adjustment scale still produces far too fine a grind even at a lower dose. Mildly frustrating at best

You'll have to keep the Italo-english in mind when reading this manual
It may just be that they started out making the adjustment knob in one piece but found that the zero setting changed so they added what sounds to be a locking nut underneath...which also may explain why your setting went off the chart....but then again, I don't know that grinder at all.

But, just by turning the knob to where the burrs touch you should be able to find a point where you are at absolute zero and work your way upwards from there, the manual says something about a stepped increment if I recall correctly...But perhaps you are more patient than I am and you can wait for NS Us to respond

They actually replied quite fast - within only 45 minutes of submitting my request! I have provided that staff member with a link to this thread in case they wish to post here (slim chance, but worth a shot).

The issue I'm experiencing is that the dial doesn't seem to be providing the proper feedback anymore. I can dial down and chirp the burrs down at proper zero, but the corresponding numbers I turn it to above this have become arbitrary. Until very recently, 4 - 4.5 was used for 18.5g doses; and 3.25 - 3.5 for 16g doses. Setting grind to above average, say 5 or 6 or 7, still produces too fine a grind - the machine is choked even with small 15-16g doses at the coarser setting. I cannot visually tell a difference between 1-2 vs 6-8, which was not the case before. Per whole number on the dial, the grind output was visually discernible. Perhaps something behind the outer shroud has become loose, and I'm just unable to adjust beyond the finest size.

In the meantime, I am stuck hand grinding shots with the Lido 2 - a fine piece that's most certainly capable of fluffy grounds and tasty drinks. Too bad I've become accustomed to a much finer grind since obtaining the Mythos. I'm able to crank out grounds that will work flawlessly for pulling shots (though it's a bit of a workout at such a fineness), but they're nowhere near as fine as what I prefer so it's necessary to dose higher than standard. Hopefully I won't be hand grinding shots for too much longer!

My Lido-2 will produce a grind fineness of talcum powder. Really don't see your problem with not fine enough.

Does the knob do anything at all? Almost sounds as if it disconnected at some point...if you're out of warranty I'd open it up and check it out (if possible without the risk of anything breaking, I see a lot of what seems plastic on the machine...)
Seems almost as if the adjustment is a wormwheel or somethIng but the explosion diagram is not clear on the method of adjustment or I'm getting seriously rusty in reading those...
Could also be that it is a simple threaded shaft pushing the upper burrup and down, as that seems the stationary one. In that case it may just have come loose or incorrectly reassembled after cleaning?

Didn't NS provide any clues where to start or what to check?

OldNuc wrote:My Lido-2 will produce a grind fineness of talcum powder. Really don't see your problem with not fine enough.

The Lido is great - but I do not desire to grind multiple 18.5g doses per morning set finer than the 9th notch. Today I used it set at 8 and 9, but the extra effort involved in cranking at 8 over 9 was really not worth the trouble. I can crank at 9 with no real stuttering / start-stop, but not the case at 8. The grinder is capable of going finer, sure, but my body's not willing/able

It's a 2011 model so certainly out of warranty. Not much plastic other than the hopper, digital panel, switch and removable tray. Everything else is metal, exterior case is all painted/coated black metal and other bits are stainless or aluminum.

The upper burr is stationary, the outer bell-housing is the neck that the hopper feeds into and functions as half of the burr chamber - top burr mounts to this. I opened / inspected / cleaned the housing, but I didn't remove the burrs from where they mount. The issue of being-stuck-grinding-too-fine was present before I did the deep clean. The deep clean was actually my attempt at further diagnosing the problem, to see if it were my machine becoming prone to choking vs my grinder producing grinds finer than requested. Now both the machine and grinder are spotless, but the grind-size issue still stands - worse now than before. If an updated knob would be an adequate fix, I'm ready to buy. Not particularly eager to remove the front panel & outer housing to try get a direct line of sight to the adjustment mechanism; but if I must then it will have to wait until next week due to a short trip monopolizing this week.

Did you ever find a solution?

My Mythos is very reluctantly reacting to changes in the grind setting. A very thorough cleaning has helped somewhat, but the main annoyance remains.