MM3 Assistance

[Rob2010SS]

Having some issues with the MM3. It's having a very hard time actually grabbing the grains and putting them through the rollers. I used to crush everything at .032" and slowly, we've had to open up the gap and start milling twice - once at .040" and then again at .036". So, obviously, something is going on.

I've seen a lot of posts about others having the same issue, where they've had to take the mill apart, clean and lubricate everything, and then put it all back together. So I think this is what I need to do.

Questions:
1. What exactly am I looking for as far as the root cause of the issue?
2. What kind of lubricant are you guys using? I'd imagine it has to be some kind of food grade something or other, right?

Thanks in advance.

 

[Rob2010SS]

Follow up to this. Brewed a hefe this weekend and could not get the grains to feed through the mill until I opened it up to .052". This was after pulling it all apart, cleaning everything thoroughly, lubricating with food grade mineral oil and re-assembling.

I've reached out to Monster Brewing Hardware for help on this one. Will follow up with what that yields after I hear back.

 

[burdbrew]

Follow up to this. Brewed a hefe this weekend and could not get the grains to feed through the mill until I opened it up to .052". This was after pulling it all apart, cleaning everything thoroughly, lubricating with food grade mineral oil and re-assembling.

I've reached out to Monster Brewing Hardware for help on this one. Will follow up with what that yields after I hear back.

I will be interested to hear what Monster tells you....

I edited because day_tripper reeled me in. Much respect....

 

[day_trippr]

Yikes!

 

[Rob2010SS]

I will be interested to hear what Monster tells you....

I edited because day_tripper reeled me in. Much respect....

Curious what your original message contained...?

 

[Rob2010SS]

Here's what Monster came back with. We're going to give this a shot and see how it goes.

it's not an exact number of spins that we're looking for.

remove the hopper completely.

completely loosen the bolts holding the frames down.

check the spin on both non-driven rollers. note how freely they spin, just get a feel for it.

slightly tighten them. they should spin just as much/freely as before.

tighten them a little more, and check the spin. If they don't spin as much, back off to where you were before.

reinstall the hopper just sitting it on top of the mill, finger tight bolts if you want, or just two finger tight.

you also need to watch the video on how to set the gap, and make sure you're at 0.040. If you don't have a feeler gauge, all this is moot. get one at your local auto parts store. ask for a blade type feeler gauge.

see how it feeds.

 

[matt_m]

Yep, loosen the bolts and be sure everything is lubed. I had these problems too until I took these steps at least a year ago, knock on wood, no trouble since.

 

[Rob2010SS]

Yep, loosen the bolts and be sure everything is lubed. I had these problems too until I took these steps at least a year ago, knock on wood, no trouble since.

Yeah, we're going to try it, see how it goes. I ripped it all apart and cleaned/lubed it up and put it back together. However, i went tight with all of the bottom bolts. So might have caused more issues there.

 

[rallenhall]

When my MM3 begins showing feed issues it's usually a sign that it needs a good cleaning. Malt dust collects around the ends of the rollers reducing the ability to spin freely. Also, brush the dust out of the roller knurls before each use. I very lightly lube with mineral oil after each cleaning ... too much attracts dust and turns it to gunk. Good luck, it's a frustrating problem to have at the start of a brew day.

 

[JohnDBrewer]

I have an mm3 and this has happened to me a twice times over the past 10+ years. I pull off the hopper and manually spin the non-drive rollers. This has resolved the issue. Never adjusted or cleaned them, just unstuck them. Not sure if it is old grain dust or what that caused it.

After it happened the first time, I now put a hand full of grain in before dumping the full grain bill in to make sure it is pulling grain through. It's a pain to dig all that grain out of the hopper which is what happened the first time.

 

[IslandLizard]

I have an MM2, and noticed the non-driven roller sometimes gets stuck. Not sure what causes it. I've made it a habit since, before filling the hopper, to jog that roller (from underneath), making sure it spins freely. Never had a problem since.

You could probably do that on both non-driven rollers on your MM-3.

There is truth to tightening the mill to the baseboard too much, or more likely, unevenly.
So tighten all four bolts evenly, as you would with lug nuts on a wheel.

 

[Group W]

I have a MM3 and set it to .035”. I also condition my grains. It gets stuck at the start of milling all the time. I use a big 1/2” drive drill to run it. So I just let the drill stop, rotate it counter clockwise about a 1/8”by hand then pull the trigger again. That usually does the trick. Another thing I notice is it starts milling better if I roll the RPMs back to start it, then give it more RPMs once the grain is running through. I also like to run the RPM as slow as possible without stressing the motor.

I also had troubles keeping the gap set. The set screws would get loose and the gap would be all over the place. A little blue thread locker on the set screws took care of that.

Hope this helps. Cheers

 

[Rob2010SS]

When my MM3 begins showing feed issues it's usually a sign that it needs a good cleaning. Malt dust collects around the ends of the rollers reducing the ability to spin freely. Also, brush the dust out of the roller knurls before each use. I very lightly lube with mineral oil after each cleaning ... too much attracts dust and turns it to gunk. Good luck, it's a frustrating problem to have at the start of a brew day.

Yeah, that's what I had read also. So I thought that was an easy fix. Unfortunately, didn't fix the issue. So going to try the other things.

I have an mm3 and this has happened to me a twice times over the past 10+ years. I pull off the hopper and manually spin the non-drive rollers. This has resolved the issue. Never adjusted or cleaned them, just unstuck them. Not sure if it is old grain dust or what that caused it.

After it happened the first time, I now put a hand full of grain in before dumping the full grain bill in to make sure it is pulling grain through. It's a pain to dig all that grain out of the hopper which is what happened the first time.

Regarding spinning the non driven rollers, this is what I was doing. Tried it a couple of times and no luck. I also go with your method of just putting a hand full of grains in to try and get them to catch. No luck either.

I've also tried operating the drill with one hand while simultaneously balancing the half full 5 gallon bucket of grains on my shoulder and starting to sprinkle them in. I've had surprising luck with that and usually works, until lately. The grains just will NOT feed through until I open the gap.

I have an MM2, and noticed the non-driven roller sometimes gets stuck. Not sure what causes it. I've made it a habit since, before filling the hopper, to jog that roller (from underneath), making sure it spins freely. Never had a problem since.

You could probably do that on both non-driven rollers on your MM-3.

There is truth to tightening the mill to the baseboard too much, or more likely, unevenly.
So tighten all four bolts evenly, as you would with lug nuts on a wheel.

Definitely tried this with no luck. Just doesn't even feed any grains in. My initial thought was bad rollers and the knurling just wasn't sharp enough. But the guy from Monster said this should definitely not be the case.

I have a MM3 and set it to .035”. I also condition my grains. It gets stuck at the start of milling all the time. I use a big 1/2” drive drill to run it. So I just let the drill stop, rotate it counter clockwise about a 1/8”by hand then pull the trigger again. That usually does the trick. Another thing I notice is it starts milling better if I roll the RPMs back to start it, then give it more RPMs once the grain is running through. I also like to run the RPM as slow as possible without stressing the motor.

I also had troubles keeping the gap set. The set screws would get loose and the gap would be all over the place. A little blue thread locker on the set screws took care of that.

Hope this helps. Cheers

Tried this also. Reverse the drill and lightly touch the trigger just to get it to back up a smidge. No luck. The grains just bounce around in the hopper and won't go into the rollers.

 

[Group W]

I never set the drill to reverse. Just reverse it by hand a smidge. Have you tried conditioning your grains? For about 11 lbs of grains I spray them with 2.5 oz of RO water. Mix really good and let them sit for about 5 minutes before milling. It softens them up a bit.

 

[Rob2010SS]

I never set the drill to reverse. Just reverse it by hand a smidge. Have you tried conditioning your grains? For about 11 lbs of grains I spray them with 2.5 oz of RO water. Mix really good and let them sit for about 5 minutes before milling. It softens them up a bit.

Like I said, when I hit the reverse, it's very little, just to see if I can jostle some grains into the rollers.

I have not tried conditioning. I've thought about it but haven't taken that step yet.

 

[JohnDBrewer]

Damn sorry to hear you have not resolved the issue. Let us know what you figure out. I don't have my mm3 hooked to a drill but a motor. Not sure if I can manual turn in reverse to try that method. My handful of grain was not a fix but a test to see if I resolved the issue after manually spinning the non-drive wheels.

I set my gap for .05, I have a three vessel RIMS. I used to run each grain separately, as at the .05 gap, some grains were not being adequately crushed and I would adjust the gap. Now I just run smaller grains twice rather than adjusting the gap. I never had issues with the gap not staying where I set it though.

I would like to try conditioning grain but have really found an easy way to do it.

 

[Rob2010SS]

Damn sorry to hear you have not resolved the issue. Let us know what you figure out. I don't have my mm3 hooked to a drill but a motor. Not sure if I can manual turn in reverse to try that method. My handful of grain was not a fix but a test to see if I resolved the issue after manually spinning the non-drive wheels.

I set my gap for .05, I have a three vessel RIMS. I used to run each grain separately, as at the .05 gap, some grains were not being adequately crushed and I would adjust the gap. Now I just run smaller grains twice rather than adjusting the gap. I never had issues with the gap not staying where I set it though.

I would like to try conditioning grain but have really found an easy way to do it.

So you run all of your grains at .050? No efficiency issues? We ran these last ones through at .052 and our efficiency took a bit of a hit. Ended up with OG of 1.045 as opposed to 1.049 on a recipe we've done more than once and had come out at 1.049. I was attributing this to the crush as we were unable to get them to go through at the .032 as we have in the past.

 

[JohnDBrewer]

Yes, I run at .05. I tried tighter and wider, but ended up back where the system I operate recommends. I run a BrewMagic and have for about 10yrs. My average efficiency on small beers (1.050ish) is consistently about 78%. Not the highest, but I know I can repeat it, time and time again. If this dips I know it usually has to do with the grain size not getting crushed properly - rye, wheat and some continental grains. Thus I look I run the gains separately and look at the crush. Took me a while to figure this out.

I also do not stir my mash once I start the recirculation. I mash in, from the bottom, stir throughly, let the grain hydrate for about 10-15 minutes, stir again, then start the recirculation, slow at first then ramp it up wide open. I then step up the mash temp to 168 for 10min and fly sparge.

 

[day_trippr]

Intentionally disturbing a grain bed once recirculation has commenced should only be an emergency reaction to a locked up mash...

Cheers!

 

[AlbertaBeer]

Probably not ever going to see it be an issue on these types of mills, but just a thought…

We run 16” diameter roller mills for feed grains, if the roller gets wore down even a fraction of the depth of the grooves, it drastically effects the feed rate of the mill. So any plugging or wear of the roller is a definite concern if you’re having feeding issues and everything else seems to be good

In our case for example with a roller that is wore down roughly 50% (visually looks like it’s ok and has life left) usually loses 80% of its capacity. It’ll drop to around 2ton/hr feed rate from 10-12ton just because the rollers don’t grab the kernels, they just sit there bouncing around on the roller face

 

[Rob2010SS]

Intentionally disturbing a grain bed once recirculation has commenced should only be an emergency reaction to a locked up mash...

Cheers!

So I started stirring the mash on the nano to help with the temperature stratification we were seeing. I stop doing that with 20 min left in the mash.

Your comment above, what are the issues with stirring? I know obviously you’re stirring all the debris back up and cosmetically the wort gets a bit cloudy again. But other than that, not sure I know any reasons why it would be detrimental?

 

[day_trippr]

I have found if I have a nice recirculation going disturbing the bed never has an upside. As you say it dislodges random debris which will then preferentially follow the highest flow which in turn means it will end up plugging paths that were working fine before putting the big spoon to the mash

So when I see something that makes me want to muck around with the mash with that spoon I try to resist that temptation, and limit my ministrations to carefully slicing shallow grid lines into the thin grey top coat that often builds up late in the mash, so it doesn't cause issues with fly sparging...

Cheers!

 

[Rob2010SS]

I always try and bring closure to threads I start as I don't like coming across threads of similar issues with no answer/solution included. That said, I think we finally have some closure here.

The MM3's have 4 locating pins in the bottom of the aluminum frame sides, 2 on each side. The locating pins hold the frames in place and then there's 4 bolts in the bottom of the wood mount that lock everything in and hold it in place.

One of the recommendations from the manufacturer was to remove the pins from side only, get everything as tight as possible, and then bolt everything down. We did this and we just ran our first grain through since, and at .040", no issues at all. Ran like it was brand new.

Not sure if some wear occurred that allowed the gaps between the side frames and the roller ends to get too big but now that those gaps are snugged up, worked perfectly!