instantkamera wrote:That may be technically true (as in, if you can get it started, tightening the grind would create more headroom under the set screw), but if you torque the set screw down reasonably well you should not be able to turn the adjustment collar (i.e. the force required to do so is greater than that needed to loosen the set screw).

I've found this to be the case with my M47, as well. Once the set screw is tightened, I'm unable to turn the adjustment collar in either direction; it's locked!

elviscaprice wrote:It may be that your not loosening enough, the set screw, before moving the settings.

This was my first thought too. I've never had a shift but I only grind up to 18g at a time and I always roast past first crack end.

So this morning I ground a large 30g batch of medium roast beans at 3.50 it tightened up slightly yet again... Would you mind explaining your thought process here? Why would loosening the top screw more (before adjusting the wheel and tightening the top screw back up) make a difference?

ScottAllyn wrote:I've found this to be the case with my M47, as well. Once the set screw is tightened, I'm unable to turn the adjustment collar in either direction; it's locked!

You should be able to tighten it with enough force, no? After all, nothing is physically keeping the adjustment collar from tightening aside from the pressure/tension asserted by the set screw. On the other hand, loosening it should indeed be impossible since the set screw is physically preventing the adjustment collar from moving in that direction.

What should keep the grinder from tightening to a finer grind during grinding is the beans themselves, especially with lighter roasts as they push down harder. As others have mentioned the thumbscrew is more important to keep the inner burr from moving down (getting coarser). As you grind beans the beans push downward on the inner burr. You can tighten the thumbscrew enough to keep the adjustment wheel from turning either way and it is absolutely necessary to loosen it before adjusting coarser. Assuming you are grinding clockwise too.

cypen wrote:You should be able to tighten it with enough force, no? After all, nothing is physically keeping the adjustment collar from tightening aside from the pressure/tension asserted by the set screw. On the other hand, loosening it should indeed be impossible since the set screw is physically preventing the adjustment collar from moving in that direction.

Maybe with a pair of pliers but certainly not with my fingers. I just gave it a good try and I have pretty strong fingers from years of playing acoustic guitar; it didn't budge. Perhaps if I used pliers... but I could probably also loosen the dial a click or two with pliers; I'd then need the pliers to loosen the set screw, tho!

Tonefish wrote:What should keep the grinder from tightening to a finer grind during grinding is the beans themselves, especially with lighter roasts as they push down harder. As others have mentioned the thumbscrew is more important to keep the inner burr from moving down (getting coarser). As you grind beans the beans push downward on the inner burr. You can tighten the thumbscrew enough to keep the adjustment wheel from turning either way and it is absolutely necessary to loosen it before adjusting coarser. Assuming you are grinding clockwise too.

Yes I agree with all of this as this is how I was thinking through it. Conversely it's also why I'm so confused as to how on Earth my grinder is tightening up a few clicks during grinding...

ScottAllyn wrote:Maybe with a pair of pliers but certainly not with my fingers. I just gave it a good try and I have pretty strong fingers from years of playing acoustic guitar; it didn't budge. Perhaps if I used pliers... but I could probably also loosen the dial a click or two with pliers; I'd then need the pliers to loosen the set screw, tho!

That really puzzles me because I can definitely tighten my adjustment wheel even after tightening my set screw as tight as I possibly can, and I don't consider myself to have hulk-fingers or anything

Interesting. I even tried locking it down between steps, thinking that I'd at least be able to get it to click into one of the steps, but it still won't budge.

Interesting indeed. I'd be interested to see if other users here are able to tighten theirs like I can.