Motorized Grain Mills: Time to show them off!

Kyled93 said:

So it may take longer, but 85 rpm ought to be fine?

As far as the torque the conversion from 90 N*m to ft lbs it's approximately 66 ft.lbs.

I assume that should be sufficient for a MM3?

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Yeah I got the ft.lb conversion and I know what pulling that on a torque wrench feels like. Comparing that to a pull on a hand crank for a mill doesn't even compare. A normal person would be spent in just a few rounds. I was trying to find a required torque instead of a recommended HP. Somebody that knew what they are doing might could convert N*m or ft.lbs to ft.lb/hr to HP. I was just trying to figure how much you could overdrive.

Short answer: 66 ft.lbs is a gracious plenty. And 85rpm while a bit slow will crush just fine.

I've been thinking about how to attach a torque wrench to my MM3 input shaft. Maybe I have a broken drill chuck somewhere? If I do I'll load up some wheat and give out some numbers.

AnOldUR said:

After looking at the Hoppopotomus set-up I'm embarrassed to show the rest of mine. That's the stuff I dream about. Great job!

Anyway, here's my project ready to do some work. Made the coupling for between the gearmotor and mill. Had to change the electric enclosure to a Radio Shack project box. The large capacitor wouldn't fit in the small box. The upper switch is the on/off. The lower is forward/reverse incase it gets jammed.



Edit to add the crush picture with gap set at about .038. Looks pretty good to me.

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Thanks man, I appreciate the compliment! Your's is much better built than mine for sure. I'm just using a simple Barley Crusher mill with a big azz 12" pulley on the mill and an old GE 1/3 hp motor (1725 rpm) with a 1 1/2" pulley to get my rpms down to 215 ish. I just hid everything in a cabinet dressed with knotty pine, cedar logs, and stone tops to match my other brewing related projects. It's just lipstick on a pig!

Fordzilla said:

Nice! I've been wanting to build my own mill but roller mills are so damn expensive. How well does that work? I've been wondering if I could power a corona mill with the clothes drier motor I have.

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It works... OK? I'm sure it doesn't compare to a roller mill, but for BIAB where I'm not worried about stuck sparges, it's fine! It definitely takes quite a bit of torque, especially on the cornmeal like crush setting I've been using.

It's a old US made mill that I bought on eBay for about 20 bucks shipped. The drill is a crappy harbor freight number that I've had sitting around for a few years. For that price, I'm not complaining. The drill smokes like crazy and stinks up the house, but I'm about to stink up the house with wort anyhow, so I guess it doesn't really matter.

ong
If your drill is smoking and "stinking up the house" there is something wrong! Please don't risk catching it, yourself, or your house on fire! Drills are cheap. New skin and Houses - not so much...

Huaco said:

ong
If your drill is smoking and "stinking up the house" there is something wrong! Please don't risk catching it, yourself, or your house on fire! Drills are cheap. New skin and Houses - not so much...

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Eh, it's just the ineffable magic of disposable Harbor Freight power tools! This drill has smoked since I bought it... Just crappy motor windings. Eventually it will stop working, but it's held out surprisingly long. I had a Cuisinart stick blender that smelled of burning plastic every time I used it, and that lasted 14 years.

Here is my new mill. MM2 powered by a vintage 1/2" drill. The drill runs about 400 rpm, so I am using a belt drive to reduce to 200 rpm.

Most everything but the mill, one pulley and bronze bushings is made from material I had laying around. The belt tensioner consists of two 2 x 4s, a drill bit and a bronze bushing.

This thing busted through two 11 pound grain bills in the past week. I will probably clean it up a little more, but I am pretty happy with it.

Vintage drill, yes. Vintage treadle sewing machine base, yes. cool? YES!

Here's mine. Sure beats my old hand crank or drill.

Looks like the same gear motor I'm using (177rpm 40 in-lbs) except there's a shaft extending out the back of mine. Did you get that from Surplus Center? Got mine quite a while ago. Don't believe they have it anymore.

AnOldUR said:

Looks like the same gear motor I'm using (177rpm 40 in-lbs) except there's a shaft extending out the back of mine. Did you get that from Surplus Center? Got mine quite a while ago. Don't believe they have it anymore.

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I have the motor that is the next size down from this (105rpm & 30 in-lbs) because surplus center wasn't selling those any longer when I went to buy one. What size wire are you guys using for the connections between the switch/motor/capacitor? I was planning on 16 ga.

Can Stepper Motors be used successfully in this application?

Huaco said:

Can Stepper Motors be used successfully in this application?

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If you put steady voltage on a stepper motor do you get it's 100% duty cycle rpm? If so, and the torque and RPMs are acceptable I'd say yes. I don't think you would want to control one and use the stepping function.

g-love said:

What size wire are you guys using for the connections between the switch/motor/capacitor? I was planning on 16 ga.

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My cord and all the wires in the box are all 16 gauge.

Here is mine. I went small and mobile.

jeepinjeepin said:

If you put steady voltage on a stepper motor do you get it's 100% duty cycle rpm? If so, and the torque and RPMs are acceptable I'd say yes. I don't think you would want to control one and use the stepping function.

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No, wasn't considering controlling one... Just mounting it and running a set rpm. I dont know injury about motors... Any experienced motor guru in here?

Huaco said:

No, wasn't considering controlling one... Just mounting it and running a set rpm. I dont know injury about motors... Any experienced motor guru in here?

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I'm gonna throw out a WAG and say that I bet you can't run them at a lower voltage for a lesser rpm. Full voltage should be the exact same as a 100% duty cycle and run it at full tilt.

Stepper motors can change speed though, right? They are used on CNC machinery for X-Y table control. Those motors don't always travel full speed when the table is moving... so that leads me to believe the RPM can be varied.

Huaco said:

Stepper motors can change speed though, right? They are used on CNC machinery for X-Y table control. Those motors don't always travel full speed when the table is moving... so that leads me to believe the RPM can be varied.

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Correct. Kinda. They move in steps. A computer program and interface tells them how far to go and how long it should take it to get there. It's not like putting 9VDC on a 12VDC motor and getting 3/4 speed.

jeepinjeepin said:

Correct. Kinda. They move in steps. A computer program and interface tells them how far to go and how long it should take it to get there. It's not like putting 9VDC on a 12VDC motor and getting 3/4 speed.

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So... they get a signal from a computer (cnc controller) that tells it how many steps to take and how fast those steps need to be? Hmm... I bet there are some Sparky's out there that could make it work. I however, am not one.

Here's mine. MM3 with a direct drive surplus gear motor at 180RPM. Efficiency master!

Huaco said:

So... they get a signal from a computer (cnc controller) that tells it how many steps to take and how fast those steps need to be? Hmm... I bet there are some Sparky's out there that could make it work. I however, am not one.

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Neither am I. I know a guy (former dance instructors friends husband) that built his own CNC router. Pretty cool. I watched him load and run a program one night without a blank on the table. I wouldn't even know what questions to ask to get started. It is also bloody expensive, especially the screws to run the X-Y axis. It's what he does for a living. I think he sets up cutting lasers.

AnOldUR said:

Looks like the same gear motor I'm using (177rpm 40 in-lbs) except there's a shaft extending out the back of mine. Did you get that from Surplus Center? Got mine quite a while ago. Don't believe they have it anymore.

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Yes, but it has been a year or two ago that I bought it.

Here's my portable mill ; )

My what a hopper!

jeepinjeepin said:

My what a hopper!

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Interestingly enough, an 18" box did not appear nearly as large when on paper! The base of the hopper holds well over 30 lbs of grain.

marcb said:

Interestingly enough, an 18" box did not appear nearly as large when on paper! The base of the hopper holds well over 30 lbs of grain.

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It's 18x18x18 above the chute?!?

jeepinjeepin said:

It's 18x18x18 above the chute?!?

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Yep

Damn that is a huge hopper.

My 90 volt dc 1/4 hp@ 150 in lbs of torque 120 rpm hopper is 10 x12 x 18

Where did you acquire your motor and controller?

e-bay 25 for the motor and 40 for the controller.

beaksnbeer said:

e-bay 25 for the motor and 40 for the controller.

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Any details on what to look for? Is this motor powerful enough to crack through the toughest of grains? I assume so, with such a high torque rating. It just seems low on HP.

Would servo motors work?

Dc motors are higher in torque in a smaller package I have crushed cara-pils and corn without bogging plus it only runs at 120rpm with the geared 90

Huaco said:

Any details on what to look for? Is this motor powerful enough to crack through the toughest of grains? I assume so, with such a high torque rating. It just seems low on HP.

Would servo motors work?

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HP is torque per period of time. Low RPMs will drop the HP of a high torque motor.

Diesel engine with 6 monster pistons that maxes at 3000rpm vs tuned up 4 cylinder import that pushes near 10,000. Both could have similar HP numbers but drastically different torque ratings.

Actually "Torque" is twisting force it has no time connotation it's force is always there. HP= Horse Power is measured in the amount ow work over a given time. Electric motors vs. engines is like comparing apples and orange similar "BUT" no the same. The Dart controller converts AC to DC along with a potentiometer to control speed. At the lower rpm of the DC gearmotor I am using I really don't need the the speed control. The gearmotor I was originally going to use was 98 inch lbs of torque at 280rpm which I have found with my mill is to fast, my crush is best between 90-150rpm range based on crush different grains as far as efficiency % goes this was my sweet spot for 80%-85%. Servo motors usually won't have the torque you want look at the gearmotors. I went with DC for the smaller size and the ease to control the speed/rpm with a potentiometer vs. pulleys and belt drives.

Grinding 60 lbs of grain for my Pliny clone tomorrow! Go niners!!!

Built this one went with direct drive, no pinch fingers in sheves. Works great.

Wow! There are some amazing mill motorizations here.

Here's my little outboard motorboat - at least that's what it reminds me of



More details in my BrewAdelaide forum post - one of the other forum members was able to source DC garage rollerdoor motors that seem to work quite well. The motor turns at 33rpm, bit slow I guess but fast eniugh fo rmy needs.