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Adjusting a MM3

Hi all. I recently got the MM3 grain mill with hopper and base. I have been looking into how to adjust the gap. Am i missing something here? Based on what I’m reading you have to remove the side panel in order to set the gap. Doing so requires partially dismantling the hopper and removing the thumb screws used to lock the adjustment. Once the gap is set, only then can you replace this panel and then reinstall the set screws. How do you then check your gap again in order to ensure that nothing has moved??? I have to be missing something. Can someone fill me in on what i’m missing?

Turn the MM3 over and read the gap through the bottom - measure between the (now) top roller and the driven roller.

^^^^ This ^^^^

That doesn’t work with a MM3. The third roller covers the gap and it can only be seen from the side. I ended up calling the company. They admit that although it can be a pain, you have to remove the hopper. Their suggestion is to adjust the mill and then mark the roller and the body so that you can visually see if anything moves because you can’t add the thumb screws until the hopper is put back on.

I didn’t just suggest something off the top of my head (or I would have added a caveat) - I use a small automotive gap tool that looks sort of like a switchblade knife, fits in sideways. No way I’m taking that big hopper off each time I want to check the gap.

Sorry, you’re right. I did this about 6 months ago and now remember removing the hopper. Sorry about that.

Want me to post a picture showing how to do it? Hilarious that the manufacturer can’t figure this out given what a PITA it is to remove the hopper.

I would definitely love to see the pics.

First pic - lay the gap tool parallel to the rollers with the desired gap “blade” extended. Second pic - twist the blade to pass between the rollers. Check the gap at both ends.


Ok, next question then. What gap setting do you find works best with your MM3?

I adjusted mine the same way as described by Shadetree. I first tried setting the gap at .035, but it wouldn’t pull grain. I bumped it back up to .039 - .040 and that works well. I have the MM3 - 2.0 with hardened steel rollers. Up to around 1.070 OG beers I routinely get 78 - 80% brewhouse efficiency batch sparging at that setting.

I normally double crush.

You double crush? Granted I’m a newb when it comes to milling but i thought that you don’t need to double crush with a three roller system. I was wondering, do you think i would be ok double crushing grains that i received crushed from the LHBS? I was warned that i’d end up with a stuck sparge. I’d really like to do so though as i noticed a lot of uncracked grains.

Honestly, I probably need to readjust my mill slightly to ensure a uniform gap across both sides. My rule of thumb is that I check after first pass, regardless of if two-roller or three-roller. If after first pass there are any noticeable uncrushed grains, and/or if the husk pieces are large and lots of chunky grist, it gets another pass.

YMMV depending on your mashtun and lautertun set up. I have a rectangular cooler into which I drilled a hole and placed a rigid tube screen (Bazooka Screen) which works like a champ, and so I can crush quite fine and not get a stuck runoff. Also, I crush until scared! :slight_smile: Practice will teach you where that line is.

Gap is less important than crush and as stated above, your MT setup is going to dictate how fine you can go. When I’m using a bag, I crush to flour but I typically batch-sparge on the thin side, so I can go pretty fine there as well since pH remains constant throughout the sparge and there’s no worry about tannin extraction from shredded husks.

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