The Beast - Monster Mill MM-2

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I purchased a Monster Mill just over a year ago, model MM-2 with two 1.5" x 6" long rollers and the 1/2" diameter shaft upgrade. Monster Brewing Hardware makes a variety of 2-roller and 3-roller models, with 1.5" and 2" diameter rollers. The rollers are available in standard 1144 steel, or 303 stainless steel. I had opted for the standard steel rollers, as I do not plan to mill wet grain and I store the mill in a dry location. With shipping, the total cost was just under $150.
I received my mill about a week and a half after I ordered it, and it arrived well-packed and ready to go. The rollers were factory-set at a gap of .045 inches, which I would later adjust. The frame of the mill is massive, comprised of 1/2" thick 6061 aluminum plates, with pressed-in oiled bronze bushings to accept the roller axles. The rollers are well-machined, with knurling that is crisp and well-defined. The mill is reversible, to allow for clockwise or counterclockwise rotation. The mill does not come with a crank handle, but those are offered by the company as an option. The aluminum frame has four 1/4-20 threaded holes on the top and bottom with hex mounting bolts to attach to a base, either above or below. Gap adjustment is performed by loosening the two set screws and rotating the knobs on the ends of the mill. The axles are cammed to provide lateral movement for adjusting the gap. Use an automotive feeler gauge to set the gap at the desired width and tighten the setscrews. I used a dab of removable Loctite to hold the set screws in place.

I chose to not buy the optional base and hopper, opting instead to build my own. I constructed a base from 3/4" thick medium-density fiberboard (MDF) and attached it to wooden legs so that I could slide a 5-gallon bucket under the mill. I also motorized my mill with a 120V, 1725 RPM induction motor I had on hand. I used pulleys and a fan belt to reduce the roller speed to around 200 RPM.

Many people use gearboxes to slow the rotational speed down, and this has a few advantages: no awkward pulleys and belts to take up space and create hazards, and no side-loading on the mill's bearings. However, since I use a pulley-and-belt system, this side-loading issue creates some concern to me, as the mill uses bronze sleeve bearings. My concern is that the side-loading will cause uneven wear on those bearings and eventually result in side-to-side play between the axle and bearing. This is my only real gripe about the Monster Mill, and I believe it would have been a better design with sealed ball bearings--at least as an upgrade option. I would have been willing to pay a little more for better bearings. As such, I may consider converting to a gearbox in the future to minimize bearing wear.
After attaching my mill to the base, I added a DIY hopper made from scraps of MDF. The hopper will hold about 7 or 8 pounds of grain.

I adjusted the roller gap to about .040" and tested the mill with a couple pounds of base malt. I dumped it into the hopper with the motor turned off, then switched it on. The rollers grabbed the kernels right away and the mill had no problem chewing through the grain in about 1 minute. While Monster recommends 1/2 HP minimum for the 2-roller mill, my motor is only 1/3 HP, but that's what I had on hand. Nevertheless, the motor had no trouble delivering enough torque to grind the malt. Since I bought the mill, I have only used it to mill a couple hundred pounds of grain, but I am pleased with the efficiency of the mill and the quality of the crush I receive. When milling harder grains, such as wheat, I found I had to pour the grain in the hopper slowly, as the kernels sometimes failed to be grabbed by the knurling and would just skid in the gap. Next time I mill wheat I may have to experiment with the roller gap to find its "sweet spot" for that type of grain.

I do BIAB, so I like a fine crush. At my gap settings the mill yields the fine crush I'm looking for, yet the hulls remain mostly intact. My brewhouse efficiency is typically in the upper 70s to low 80s.
Cleanup and maintenance are easy. After milling, I just use a clean paintbrush to brush off the grain dust. I store my mill in a dry, indoor location, but if I was concerned about corrosion, I would wipe a bit of mineral oil on the rollers.
Overall, I am extremely pleased with the Monster Mill. On a 5-star scale, I would give it 4.5.
 
After researching the different mills available for features and cost, I concluded that the MM-2 was the best bang for my buck too. Then I compared it to a friend's Barley Crusher and came away even more pleased with my purchase. the MM-2 is build like a tank in comparison.
 
I'm not concerned about the brass bushings, most garage door operators use something similar and they get much more use and way more lateral pull. Also I've had a few mills and I love the monster lineup.
 
@Arrheinous
Harbor Freight has a 1/2" hole shooter for about $100. It has a setting for 300 rpm and it works great. I use an old skill 1/2" monster from the 60's. Runs at 300 rpm and the crush is great with my MM-3. Going to a motor and gear reducer soon, but these drills do work just fine.
 
Well Im sure the MM2 is a great mill. That said I have barley crusher. Ive run 60 some 5 gallon batches through it and it shows no sign of quit whats-so-ever. Its never even needed readjustment and I check it every other batch with a feeler gauge. I use it with a simple 12v dewalt drill and while that drill can get hot doing a 10 gallon grain bill it all just keeps on going, so lets not bang on another product. It may not be as hevily constrcuted etc but that deosnt mean its not a quality unit.
 
So it's just like a Barley Crusher... accept it costs significantly more for a usable setup because it has a trendy name on it... Print Disney on the side of it and charge another 75$
 
Nice job on your mill, Kevin. With a different crusher I did something similar, with an old cabinet I had and even older 1/2hp motor laying around. Between the motor power and extra torque from the belt reduction (like yours), I haven't seen the grind that even slows it down.
Trendy name? I like that name, and looked very hard at the MM grinders. That said, though, I ended up with a Chinese grinder head, the Cereal Killer, that does have ball bearings. How long it will last, who knows, but so far so good.
Nice mill!
 
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