ToV

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I am in the process of assembling the parts to add a motorized mill to my brewing collection.

I have tried to search the forum and other websites for description of acceptable RPMs. But, all I see is "175 is the sweet spot", "keep it under 300 unless you are ok with a little more flour", "I run mine at 250".

What I am really looking for is a minimum RPM. I keep hearing sweet spot, but no one explains if that is crush quality or balance of speed vs. quality. It seems that every someone asks about a speed they say I am looking at X,Y,or Z motor and get a "that will work fine" response. Is the crush at 50, 75, 100, 125, 150 RPM and so on the same or is there a noticeable difference?

beaksnbeer

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250 is high in my opinion I use a 90v DC gear motor 175 rpm but @ 78lbs of torque crush is great some want more speed to shorten the time it takes to crush. I have found the faster (higher rpm) the more flour I get with my gap set at .39 I have a controller that I can slow or speed up depending on what I need for different grains. Now my mill is a 4 to 1 ratio to the hand crank which I calculated to run mine @128rpm is my sweet spot for base grains I also damp mill great crush most husk intact rye and wheat I run at .36 and 90 rpm. I went with a DC motor for the control and the higher torque in a small package.

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ToV

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what are you using as a power supply? I figured DC would add a fair bit to the cost because of the additional part. Come to think of it I might have an old desktop power supply around here somewhere, does anyone know if one of those will drive a DC motor for a mill?

beaksnbeer

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Depends on the voltage of either. I would need at least a 1hp AC motor but only a 1/8 DC picked up a Dart 250 controller off e-bay for $30 and the motor for $50 lovejoy coupler I already had.

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jammin

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I would get the appropriate gear reduction parts AFTER you get a mill and motor.

Different mills can run at different speeds. It's all about finding the right speed to develop a proper crush. A proper crush will break the kernal down into at least 2-3 pieces and knock them out of the husk. The integrity of the husk will also be dependant on your system. If you have trouble with lautering rates, you will need to be conservative with your husk integrity to avoid stuck mashes and save time on your brew day. If you're having serious trouble with getting good husks, you might consider conditioning your malt with 2% water by weight.

What is your budget for a mill? If you have the coin, the Monster Mill 2 roller with 2 inch rollers is a sweetheart.

I run my MM3 2.0 at about 157 RPM's and the crush is perfect for my Blichmann false bottom (10 gallon kettle). I get a good balance of efficiency and quick lautering times and never have to worry about a stuck sparge.

ToV

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I hope to operate a gear motor and not the pulley system and most of the motors I am looking are being sold already attached to a gear head. As a result, I need to figure mill speed (or if I go the VDC route, maximum mill speed) in advance.

Regarding budget, low enough that I can honestly tell SWMBO that the packages arriving don't do major damage to a new house down payment.

As Far as mills go, I had settled on the Moster Mill brand, but am still deciding between MM 2 roller v.2 (the one you recommended) or Moster Mill 3 with the 1.5 inch rollers.

Thanks for the input everyone. I have everything else setup, a kegerator, an electric brew rig with recirculating mash HERMS. The grain mill should allow me to break free of the store and order grains in bulk (or to not hand crank all of them at the store). I hope this will be my last brewery upgrade for a while . . . at least until I move and have to adapt to a new space.