mill gap issues

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odie

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having trouble getting my mill to keep crushing. If I set the gap tight with a credit card it doesn't want to pull in any grain. the free spinning second roller just won't move. It seems not enough of the grain can get between the rollers to bite into the unpowered roller to get it to turn.

I have to set my gap coarse like a HBS store to do my first run. Then I can tighten up the gap for a second run or even a third run.

Is this normal or are my rollers perhaps out of alignment or something like that?

I guess a better crusher would have the second roller gear driven off the first one so it's forced to roll and crush.
 

jdauria

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I have this issue occasionally with my Barley Crusher. When it happens I just take the whole thing apart and clean the rollers and lube the shaft the rollers attach to and it works fine afterwards.
 
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odie

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I can reach underneath and easily spin the roller. It just kinda seems that the gap is too tight for the whole grains to drop into the gap and let the roller "teeth" grab onto it and pull it into the crush zone.
 

JimRausch

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odie- I have the exact same issue that you describe. My solution has been what you suggest- mill first at the wider gap, then tighten it up and run it through again. I'll be interested to see if there is another solution.
 

cubalz

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That does not sound right, you should not have to do "pre crushing". From what you wrote, I assume yours is a 2 roller mill which can have feed rate issues due to only having one feed roller. I have a Monster Mill 3 that I have been using for years with no issue no matter what gap I set it at. My suggestion is to purchase a 3 roller model (your choice of brand) and kick your 2 roller to the curb.
 

Robert65

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A good quality two roller mill is exactly what you want. There no such thing as a three roller mill in the real brewing world. They just sell because they look cool to homebrewers, while the third roller serves no purpose (some claim it "loosens the husk," which isn't a necessary function) other than to be an additional potential point of failure. (If one non driven roller won't turn, neither will two.) I agree that if you are not getting it to feed properly, the problem is torque, not mill configuration. Low speed (</= 150 rpm,) steady power is required. A single pass at the desired gap will give the best crush.
 

MuddyBrown

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I've got a crappy mill. I am unable to upgrade to a better mill at this time. In my searching for a solution to fix my solution, I found that others got two o-rings around the size of the rollers, then placed them at either ends of the powered roller. Then you need to put a touch of metal tape at inside of the hopper to help prevent grain from getting to the o-rings or they will wear down quickly. I've only used this a couple of times, and it seems to work well. Not sure how long it lasts for.
 
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odie

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I’m using a 1/2 drill. No power issues. Just seems that the grain wants to hang up right above the gap so the rollers are just grabbing air
 

ba-brewer

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I have a cereal killer mill and had issue when I could not get the grain to mill if I filled the hopper first then started the drill. It also seem to make whole kernels go into the bucket, going the wrong way over the free wheel I think.

What I do now is start the drill then drop a few a kernel in slowly, once the free wheel starts spinning I dump in my grain and all is well.
 

apl_seed

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This sounds like a roller issue rather than a torque issue. Look at the knurls on each roller. If they are flat instead of pointed, there's your issue. I had your exact problem till I bought a new mill. Now I can rip through 13 lbs of grain in less than 3 minutes with a 3/8 drive cordless drill and still get 80+% efficiency.
 
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odie

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It’s a new mill, but not sure how pointed vs flat without another on hand to compare. I can slip my hand underneath and flick the free roller a couple times and then it bites and crushes fine for a while or not
 

Bilsch

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A good quality two roller mill is exactly what you want. There no such thing as a three roller mill in the real brewing world. They just sell because they look cool to homebrewers, while the third roller serves no purpose (some claim it "loosens the husk," which isn't a necessary function) other than to be an additional potential point of failure. (If one non driven roller won't turn, neither will two.) I agree that if you are not getting it to feed properly, the problem is torque, not mill configuration. Low speed (</= 150 rpm,) steady power is required. A single pass at the desired gap will give the best crush.
I have to respectfully disagree with you on your assertion that the third roller, or first depending on how you look at it, is superfluous. In my MM3 the first gap is wider however it does make a coarse crush and then the second gap performs the final specified crush. The kernels taken in two steps like this see a smaller lead in angle on each roll therefore is less chance to bind then if trying to reduce the size by 100% on one pass. This is sort of what the OP is learning from having to make two passes.
 

Robert65

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I have to respectfully disagree with you on your assertion that the third roller, or first depending on how you look at it, is superfluous. In my MM3 the first gap is wider however it does make a coarse crush and then the second gap performs the final specified crush. The kernels taken in two steps like this see a smaller lead in angle on each roll therefore is less chance to bind then if trying to reduce the size by 100% on one pass. This is sort of what the OP is learning from having to make two passes.
Point well taken, Russ. However, my MM2 Pro delivers superb results, however tight I set the gap, provided the grain is conditioned. With conditioning, I wouldn't think the "pre crush" would be a very significant improvement. It seems to me it serves a similar purpose. But I gather you can testify to the contrary. And of course I also benefit from larger roller size (unless you're also talking about the MM3 Pro with 2" rollers.) Anyway, this does lead me to a (perhaps more helpful) thought... maybe the OP should look into conditioning. Heck, just eliminating all the dust should make that worthwhile to any brewer. Cheers.
 

IslandLizard

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Good to first check that the slave roller spins freely. That's essential!
I have to make sure that roller spins freely on my MM2 too, or it won't do diddly.

Have you tried starting the mill before adding grain to the hopper?
 

Robert65

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Good to make sure to first check the slave roller spins freely. That's essential!
I have to make sure that roller spins freely on my MM2 or it won't do diddly.

Have you tried starting the mill before adding grain to the hopper?
I've actually found that adding grain to my running mill stalls the drill (maybe I've just not adequately determined the correct speed to have it going at,) while I never have trouble starting up the mill with grain already in ths hopper. YMMV, so many possible variables in mills, drills, etc.
 

Bilsch

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Point well taken, Russ. However, my MM2 Pro delivers superb results, however tight I set the gap, provided the grain is conditioned. With conditioning, I wouldn't think the "pre crush" would be a very significant improvement. It seems to me it serves a similar purpose. But I gather you can testify to the contrary. And of course I also benefit from larger roller size (unless you're also talking about the MM3 Pro with 2" rollers.) Anyway, this does lead me to a (perhaps more helpful) thought... maybe the OP should look into conditioning. Heck, just eliminating all the dust should make that worthwhile to any brewer. Cheers.
Agreed, certainly conditioning the grain makes a huge difference in how the rolls can pull in the kernels and of course the roll diameter, bigger being better. If you look at the commercial German mills they are generally 2 driven rolls but they are big, like 8" or more so there is no way the grain could stall at the entry. Personally I think the 3 roll mill is a homebrew hack to make it possible to dry mill finely while using inexpensive small diameter rollers where only a single roll is driven and the others idle. I would expect that all our experience will be different but for the record I am happier with the dry grind from my MM3 (non pro) then with my previous 2 roll conditioned.
 

LittleRiver

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I use the Kegco 3 roller mill, with a 1/2" low speed high torque drill. My gap setting is .025" (which is a bit less than credit card thickness, which run ~.032"). I set the gap when I first got it, and haven't adjusted it since.

I've been using it for 3 years. I've never had any of the problems described in this thread. I fill the hopper full, then start the drill, and take away a bucket of finely crushed grain. It's that easy, every time.
 

stickyfinger

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If your second roller won't start going, all you have to do is poke down a SS knife, like a butter knife, and gently nudge the non-driven roller down as you slowly turn on the drill. If you do it carefully you can force the non-driven roller to grab the malt. Once it gets going, it usually will keep going as long as malt is always on top of it and being pulled in. You just have to be careful to not let the knife get pulled into the mill (not a huge deal but annoying.)

If you start conditioning the malt, it will pull through fine with a pretty fine setting, but it takes extra time. The result is much better husk integrity after the crush as well.
 

lump42

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I’m using a 1/2 drill. No power issues. Just seems that the grain wants to hang up right above the gap so the rollers are just grabbing air

I've had this issue with the barley crusher. The drill has to run so slow that the trigger is barely pulled. I examined the rollers and they are quite a few missing points. I've just taken to using the hand crank and count it as exercise.
 

IslandLizard

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I've actually found that adding grain to my running mill stalls the drill (maybe I've just not adequately determined the correct speed to have it going at,)
Yeah, for that you need to have it spinning at a much higher speed. I'd say, judging by the sound, the grain cuts the speed in half compared to running idle. That's using the 1/2" Heavy Duty Low Speed drill from HF, the older model with a speed preset/limiter wheel.
 

stickyfinger

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I've had this issue with the barley crusher. The drill has to run so slow that the trigger is barely pulled. I examined the rollers and they are quite a few missing points. I've just taken to using the hand crank and count it as exercise.
i also use a barley crusher, one from like 16 years ago! it still works like a dream with a drill. i think i have mine set at maybe 30 mil or 35 mil at this point. i think 30 mil, but i condition the malt. i think 25 mil was too narrow and was making it hard to get the rollers to grab the malt even after conditioning it.
 

thespiff

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I just had this issue after adjusting the gap on my barley crusher. I was able to resolve it by loosening the screws slightly on the non-driven roller. During my adjustment somehow the non-driven roller was tightened to the point that it didn't spin freely. It was still spinnable but there was a bit of resistance, which was enough to prevent the grain from catching and passing through the rollers.

I'll also point out that Feeler Gauge Sets are very cheap on amazon, you should consider buying one for more precise calibration of your gap.
 

IslandLizard

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I was able to resolve it by loosening the screws slightly on the non-driven roller.
If loosening the set screws let the roller spin again wouldn't that mean they were deforming (compressing) the bearings? How tight were they?

I've had to realign the sides of my Monster Mill (MM2) when the slave roller was binding (and stopped spinning). That fixed it.
 

gozer

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I have a MM3 and it constantly slips. I've tried everything. I take it apart and clean it. I've set the gap wider than I would want. I've contacted monstemill. I've read all the horror stories of mill failures and hacks to get them to work. Every brewday is a hassle. It ALWAYS slips until I get lucky and it catches and will then mill the whole batch just fine. This is unacceptable. Monster mill even admitted that the 3 roller system was prone to slipping, and the 2 roller setup would be more reliable.

I dumped a good hunk of cash on this POS and now I'm stuck with it. Thinking about downgrading to a 2 roller system from another company.

So yeah. It's not just you.
 

Bilsch

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Yea those stupid butter bolt wing screws they send with it suck. Go to the hardware store and get some proper hardened allen socket set screws to replace those, but get the longer ones.. like 3/4” and use a bit of antisieze on them. Your problem will be solved.
 
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