monster mill problems

So i have a question for anyone who uses a motorized mill. Do you guys regulary disassemble your mills and re oil them? If so how often? I've had this mill for about six months now and its been working great until about a month ago. The non drive roller just stops grabbing the grain. I assume the bearings need oil, I just havent got around to it since I built the stand and hopper in a way that it all needs to come apart first before i can get at the actual mill. I think ill redesign everything once its apart.

I have the same problem with grabbing the grain. I had to open up the lower gap to max to get it to grab. I think my efficiency is suffering as a result.

I've never oiled my bearings. I don't see how the bearing needing oil would keep the roller from grabbing the grain. If it's a sleeve bearing there's nothing to oil, the axle just spins inside the sleeve. I've had my mill about a year, made many batches, and even left it out in the rain and it still works just as well as it did when I got it (after cleaning the rust off the rollers, that is). It sounds like the knurling needs to be cleaned out, there's probably too much dust embedded in it. Joety, if you have to open the gap to max, your efficiency is going to be crap, since your grain is barely going to be cracked, much less crushed.

Lack of lubrication can hurt the rollers ability to grab grain in a sense, yes. If the roller "sticks", it will not turn simply by the the action of the "drive" roller spinning and pulling grain through the gap. What you then have is #1 either no grain getting pulled through or #2 you have one roller pullng grain PAST the other roller, thus shredding it instead of crushing it.

On the Barley crusher the DRIVE roller has an O-ring that squshes between it and the other roller, thus causing enough friction to drive BOTH rollers. They say that after that Oring wears out, that the action of the grain passing between the rollers will be sufficient to turn the "dead" roller... but I presume if your gap is either too large or too small, it will not work that way,

I have ran hundreds of pounds through my motorized Monster Mill and it grabs like a hero. I did once run a couple pounds of oats through in the grist for an Oatmeal stout and that gummed up the dummy roller pretty bad. I had to dump the grain out and push the dummy roller backwards until it dislodged all the gummy stuff. I set mine to .037 and haven't moved it since, so you should not have to loosen the gap either.

So I would start by disassembling the mill and making sure there isn't grain bits caught around the axles of the free roller. If it still isn't spinning free you could try putting some grease in there, but unless there is rust buildup or something you really shouldn't need to. The Monster Mill has oil impregnated bushings that do not require periodic greasing. Someone else mentioned making sure your knurls aren't getting packed full of grain dust and bits, so you might also take a coarse bristled brush to those.

My maltmill had teh same issue once I motorized it. Fortunately, my hopper design is such that the sides of the mill are exposed so a shot of WD got everything going nicely.

Best crush I have had to date. I suspect it has more to do with my rpm than anything.

There is a possibility that the mill frame is out of alignment and not square with the rollers. This can cause the rollers to bind up. A similar problem can be caused if there isn't enough clearance at the roller ends.

Tonedef131 said:

So I would start by disassembling the mill and making sure there isn't grain bits caught around the axles of the free roller. If it still isn't spinning free you could try putting some grease in there, but unless there is rust buildup or something you really shouldn't need to. The Monster Mill has oil impregnated bushings that do not require periodic greasing. Someone else mentioned making sure your knurls aren't getting packed full of grain dust and bits, so you might also take a coarse bristled brush to those.

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Getting grain bits stuck around the ends will cause this problem for me. I use a drill to drive my mill, so it isn't that big of a deal for me, as I can just reverse the drill for a couple seconds, and it clears everything out. A good cleaning, and a light oiling of the bushings and axles, helped me alot.

EvilTOJ said:

Joety, if you have to open the gap to max, your efficiency is going to be crap, since your grain is barely going to be cracked, much less crushed.

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I realize that, but the grain is definitely being crushed and not visibly different from the LHBS grain. Mine is a three roller model, so the gap is only the lower gap. The upper gap is not adjustable.

thanks guys for your suggestions, this last crush where i had the most problems was with alot of oats. i cant see much gummed up in the knurls but i am going to check the axles. that seems more likely to be the problem.

Tonedef131 said:

If it still isn't spinning free you could try putting some grease in there, but unless there is rust buildup or something you really shouldn't need to. The Monster Mill has oil impregnated bushings that do not require periodic greasing.

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You DO NOT ADD GREASE to oillite bushings, this is about as bad as letting them go dry from years or many hours use. Grease will seal the pores of the oilite bushings not allowing the oil to wick to the surface and lubricate the steel or stainless steel shafts. Take apart, clean but no solvent, brake clean or carb cleaner to the bushings. Only then add oil to the bushings to a wet surface look, let them soak up the oil over night. Maybe add a few more drops the next day again letting the oillite sponge material time to soak up more oil. If your afraid of motor oil use Olive Oil PopEye won't mind. Wipe off the excess then assemble. As mentioned above check the end frame alignment for free spinning of the drums after it's fully assembled and tightened down. I would use a feeler gauge or better yet three thin strips of shim stock like 0.0015" thick behind all 3 rollers at once then pull the ends together while tightening the frame bolts. Only then remove the shim stock. This way your end clearance will be at the minimum not allowing grain and dust to get past the drums and side plates this also keeps the bushings running cleaner. Check the surface of the end plates as well the drum ends for any grooves or scaring from grit or grain material caught between them, sand paper smooth if needed. If you sand or polish down first add paper towels or napkins packed into the bushing preventing grit particles getting into the oillite material. Also check the alignment so the drums spin freely. If it were my Mill as they are not cheap it's worth the added attention like a regular maintenance schedule. This should add many more years life to them.
JMO's here.

Grain dust and grease don't mix.

I agree with BrewBeemer

Bottom view of my motorized mill after many years of use.
Once a year the mill gets cleaned with compressed air.



Cheers,
ClaudiusB