Hi guys! Don't know if anyone will ever respond back. Though, this is a topic that I haven't found being discussed anywhere.
Wanted to ask, for all your experience:

- When you switch to the coarsest grind and grind some beans (on any grinder), then switch back to your previous dial-in espresso grind setting, - is your setting now off-balanced and do you have to dial-in again?

Does it happen on any grinder in the world, or just to my grinder? I'm using Baratza Vario. And this is the reason I bought it: to use it and for v60 and for espresso. While of course single-dosing.

to confirm it with 'data':
I did a small test and instead of an already perfect dialed-in shot of 1x2 ratio (18g vs 36ml within 30 sec), I got 2 consecutive shots of 47ml and 43ml on the same grind setting. Taste was also a bit bland of course.

So, do you know from your experience - is it a problem of all grinders, or only of Vario? Or only of my Vario in particular?

The topic, especially with respect to the Vario, has been covered many times - most recently, earlier today : Best "all in one" grinder to go back and fourth between espresso and pourover (under $1000)?

You'll probably run into one of my old posts in earlier threads talking about my experience switching back and forth from pour-over to espresso with my old Vario with ceramic burrs. I didn't have any major problems, but I use a more forgiving lever to pull the shots and I would dial in my espresso shots more by the noise that the grinder made when adjusting finer than the actual setting.

I've since upgraded to a WWW Key grinder for espresso and had my Vario refurbed and upgraded to steel burrs for dedicated pour-over duty and I've been very happy with the results with an improvement for both espresso and pour-over.

My Eureka Mignon Specialita has this problem. It requires re-dialing in for espresso after large grind changes for different brew methods. As a result, I use it for espresso only.

My Niche Zero does not have this problem. It's huge grind dial (the diameter of the grinder body) is a joy to adjust, and the adjustments are repeatable. I believe this is one of the reasons the Niche is such a popular grinder.

I think it depends on the grinder. My first generation Monolith Flat repeats perfectly.

I asked this question regarding my Arco in the Arco thread here and received a really informative reply from Peter (engineer of the Arco) that explained the "backlash" phenomenon.

It's the last post on this page:
Arco by goat story

He says backlash is an issue when adjusting coarser to pour-over, not when adjusting finer.

Backlash is always a factor when you change directions.

For high precision motion devices, there is typically a "unidirectional repeatability" and a "bidirectional repeatability" in the datasheet, where the first one is always better than the second one.
It is important to always dial in from one side. For grinder it is typically from coarse to fine (for the obvious reasons that you can always set a coarser size, but not always finer).

I know that for some grinder this results in a burr position after setting grind size which is slightly different than the size during grinding, so it might be better for some grinder to adjust from the finer side, but to set the grind size from one direction is way more important than setting it "from the right side".

mycatsnameisbernie wrote:My Eureka Mignon Specialita has this problem. It requires re-dialing in for espresso after large grind changes for different brew methods. As a result, I use it for espresso only.

My Niche Zero does not have this problem. It's huge grind dial (the diameter of the grinder body) is a joy to adjust, and the adjustments are repeatable. I believe this is one of the reasons the Niche is such a popular grinder.

My eureka suffers from the same fate.

Intuitively speaking - with no first hand expertise - I think the grinders with worm gear adjusters are the best for this. Anfim (s)cody, compak F8/10.

My Specialita could never get the same grind when going back to the same setting after some adjustment, not well suited to "frequent" bean changing, better to have extra beans to dial in again each change. The mechanism of adjusting the height of the motor/lower burr using a long screw and using that same screw to read the setting is inherently non-repeatable with the loose tolerances not meant for such accuracy.

I might be in the minority but I find my NZ also has some issues with "bidirectional repeatability": the black plastic ring that holds the upper burr has two guide posts that the springs push up on, it's between those posts and the body that the plastic flexes ever so slightly so I always have to loosen the grind setting before tightening back to the desired setting to get more consistent results. I really wish they made this part out of metal instead of plastic.

Even my Ceado E37S with the worm gear adjustment suffers from "bidirectional repeatability": I noticed this when dialing in the zero point, the burrs were ever so slightly touching but when I changed the direction of the adjustment collar the two burrs did the opposite of move further apart and locked together, the upper burr assembly was probably tilting in a strange way where the wave spring inside wasn't pushing up on it. Thankfully going from coarse to fine realigns the top assembly and it's repeatable so I always make sure to dial in from this direction.