Old Box Fan = Motor for MaltMill?

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Mirilis

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So I was thinking, I have an old box fan.. if i took the blade off of it and attached a fly wheel, would I be able to use it to hook to my malt mill..

I think the target I want is 200-300 RPM, but If i turn it to high i could get about 500 RPM out of it. I need to crunch some numbers and do some testing. I was just wondering if anyone else had tried this yet
 
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If it's a box fan like I'm picturing, I doubt it would have anywhere near enough power. Now if it's a blower motor from an HVAC system, that'll be about 1/2 hp and have plenty of power.
 

Laughing_Gnome_Invisible

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It won't have the torque. I recently hooked up a bench grinder to mine, even that didn't have the power to start the grind.........I'm not giving up though! :D
 

Tonedef131

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I can stop the blades on those fans with my hand, even when it's at full speed. This tells me that it would be grossly underpowered for the task.
 

wilserbrewer

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IMO the motor is too small unless you gear it way, way down to say 10 - 20 rpms at the mill. Better choices for a motor at most scrapyards I would imagine.

I often wonder why so many go to great lengths to motorize a mill, when you can buy a heavy duty drill for peanuts. Sure, there are some great builds out there that are very professional, but to purchase pulleys and belts for an old wahing machine motor???

fifty bucks here and done.....
- Harbor Freight Tools - Quality Tools at the Lowest Prices

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93632
 

Catt22

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Big belts and pulleys seem to have a Steampunk attribute that enhances the visual impact of the mill. A used surplus gear motor from ebay or wherever is a good choice for the most elegant configuration. A 1/2" cheap corded drill motor is probably the most economical and easiest way to motorize a mill. One could use u-bolts to clamp down the drill motor on a platform or table and connect to the mill with a flex coupling of some kind for a more permanent installation. With a custom mill stand, you could probably conceal the drill motor for a cleaner appearance.
 

conpewter

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I want to motorize because I'd like to get it down below 200 RPM, None of my corded drills will run at that speed with any torque. My cordless screwgun will but I want to build this into a cabinet where I can just flick a switch.

I also want the gearmotor because it will actually fit inside the cabinet, otherwise I need a big pully sticking out the top, looks good for some builds, wouldn't be good for mine.
 

Catt22

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I want to motorize because I'd like to get it down below 200 RPM, None of my corded drills will run at that speed with any torque. My cordless screwgun will but I want to build this into a cabinet where I can just flick a switch.

I also want the gearmotor because it will actually fit inside the cabinet, otherwise I need a big pully sticking out the top, looks good for some builds, wouldn't be good for mine.
My mill runs at 115 RPM which is generally considered slow, but I'm very happy with it. I'm guessing it will mill about two pounds per minute or so and produces very little dust. That's plenty fast for me and the lack of a dust cloud is very cool.
 

Dwain

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Laughing Gnome,
It won't have the torque. I recently hooked up a bench grinder to mine, even that didn't have the power to start the grind.........I'm not giving up though!
If you put pulleys on it, what about using a cam/idler pulley that you engage after the grinder motor gets up to full speed. You could put it on a handle and latch it once it's engaged. Luck - Dwain
 

lapdog

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Here's a picture of mine (with the guard removed)
I'm on the same page as Wilserbrewer. Harbor Freight. I know they're not everywhere though. Rather than buying just the motor the small table top drill press was onsale for $40. So I bought that took the motor off and all of the switch assembly. The belt and pulley I picked up from Graingers. That was about $15. The plywood was free scrap from a local cabinetmaker.



I havent clocked it exactly but I think with the gear ratio it spins in the 200-300 rpm range.

I have a few more pics on my website

and at Picasa Web Albums - Chris - beer projects

I built a slide door so that I'm not starting the mill up with grain against the rollers. I can also control the flowrate.
 

BrewBeemer

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It won't have the torque. I recently hooked up a bench grinder to mine, even that didn't have the power to start the grind.........I'm not giving up though! :D
What? Grinders are 3,450 rpm's you in a hurry grinding grain?
Well 3/4 HP on up can be had with 1,750 rpm's also.
Grinders do not have the starting torque like a compressor motor
or one connected to a well or hydraulic pump.
Factor in the diameter of your knurled rollers also.

Like them "low riders, be slow and be cool" for minimum
flour with less grain tearing and damage.
I can work around a 12 minute grain crush in the morning
while doing other things while heating water.

Remember the speed of the grain going thru the mill is quite different
in inches per / second or feet per / second depending on the rollers diameters.
Same speed reduction on a 1 1/2" roller mill vs a 2" roller mill the surface speed
increase is 1.333 times the smaller roller mill or .75 times going the other way in
mill roller diameters. Your 200 rpm 1 1/2" diameter roller mill will have a roller surface
speed of 942 inches a minute vs a 2" roller mill at 1,256.6 inches a minute surface speed.
Your 200 rpm's on the smaller 1 1/2" roller mill is like 266 rpm's on the 1 1/2" mill with a 2"
roller mills surface speed.
Manufactures sell their mills pushing the limits to get the highest numbers or pounds a
minute their unit can crush vs other manufactures, the winner there is the loser, you
unless you like making extra flour. I don't.
 

HomebrewJeff

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IMO the motor is too small unless you gear it way, way down to say 10 - 20 rpms at the mill. Better choices for a motor at most scrapyards I would imagine.

I often wonder why so many go to great lengths to motorize a mill, when you can buy a heavy duty drill for peanuts. Sure, there are some great builds out there that are very professional, but to purchase pulleys and belts for an old wahing machine motor???

fifty bucks here and done.....
- Harbor Freight Tools - Quality Tools at the Lowest Prices

- Harbor Freight Tools - Quality Tools at the Lowest Prices
I think with most homebrewers, the "Yep, I made that..." factor is very high on the list. Being able to say that you salvaged this old motor from this old "thing" you got for free rates high on the coolness factor. Second on the coolness factor list is buying something new that is used for something completely different (i.e. 48qt cooler, stainless braided hose) and making it work in your system. Just my take on the "why build it" question.

+1 on Harbor Freight... they have lots of cool tools that you could hack into and use on a mill. I'm sure you could remove most of the shell on that drill, rewire the drill, put a shroud over it, and no one would ever know it used to be a drill. :ban:
 

alee

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Here's a picture of my recent build. I used the motor off an old dryer I had in the barn. Works nice and slow also. I seem to have increased my efficiency from 70 to 80% since using the motor instead of my variable speed drill.
It does require a little kick start to get the mill going, but once moving there's no stopping it (except with the switch!)
 

BrewBeemer

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alee; so what your saying is that your constant speed mill gave you a grain efficiency increase vs the electric drill motor that will have the operator working with a non constant speed during their grain crush or is this because your speed is slower a drill motor? That must be a 1,100 or 1,300 rpm motor vs a 1,750 rpm motor for less pulley speed reduction.
What's your final rpm's at the rollers? diameter of rollers changes the rollers surface speed in inches or feet per / minute that means a big difference also.

With a disability industrially rated 1/3 HP Baldor motor and worm drive gearbox as a single unit I only have 28.75 rpm shaft output speed. This with a short chain a inch between sprockets the gearing up by 3.111 to a jackshaft allowed me 89.44 rpms across the gearbox with the jackshaft supported by two pillow bearings with a LoveJoy coupling drive direct to the Monster Mill 3-2.0, a 3 roller 2" roller diameter mill. The roller surface speed is 562 inches a minute or 46.83 feet per minute. Rather slow but flour free. It will eat thru 54 pounds of grain for a stout for three 5 gallon corny's filled after fermentation in rather fast time while working on the HLT and MLT heating. No waiting around for the grain mill by any means.

Those Harbor Freight motors are cheap enough, just mount one with the speed control set to your grain mills running speed plus parallel tap across the speed controller to a momentary contact switch for that short instant high speed to get the mill started with a full hopper. This way you will have a constant speed power supply no variable finger control with still the extra burst of power needed get it started milling under a hopper filled load.
That or use a Router speed controller mounted next to your mill unit.

I priced out the 1/3 hp Baldor gearbox unit I have and thru the disability business I got from in the family and it was a $1,739 unit, for free I will use it plus I have a on, off, forward and reverse should it eat a shirt dog or other unwanted object. This unit also removes having a large pulley hazard to be covered up plus more importantly a direct drive no side loading on the mills drive bushing.
 

Simphoto02

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I can stop the blades on those fans with my hand, even when it's at full speed. This tells me that it would be grossly underpowered for the task.
I agree. A good way to test it. If fingers fly off, there should be plenty of power to grind grains.

Does anybody else see a problem with this method?
 

Catt22

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And no one's tried a chain saw engine yet? That would wake the neighbors up early on a Saturday morning! A small steam engine would be even cooler!
 

Tonedef131

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I agree. A good way to test it. If fingers fly off, there should be plenty of power to grind grains.

Does anybody else see a problem with this method?
lol for the record I do not advocate testing mills by trying to stop them with body parts. I was just sayin that fans can be stopped with you hand so I doubt it's going to be able to handle crushing grain.

And no one's tried a chain saw engine yet? That would wake the neighbors up early on a Saturday morning! A small steam engine would be even cooler!
Best idea in any thread ever. Anything with a 2 stroke motor is automatically cooler than anything without one.
 

Hang Glider

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oh yeah! and design something so the auger can be easily attached/removed - so it can be used to move the grain into the hopper before milling...and to move the spent grains out of the mash tun...
 

Catt22

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I wonder if a very large concrete flywheel could power a mill. A concrete flywheel 2 ft. in diameter and a little more than 4 feet long would weigh in at near 1 ton. It could store a lot of usable energy when spinning. I've heard of flywheel powered generators being used in lieu of battery backup for computer servers. Same principle, but I think the mill could use the rotational force of the flywheel directly.
 

BrewBeemer

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I wonder if a very large concrete flywheel could power a mill. A concrete flywheel 2 ft. in diameter and a little more than 4 feet long would weigh in at near 1 ton. It could store a lot of usable energy when spinning. I've heard of flywheel powered generators being used in lieu of battery backup for computer servers. Same principle, but I think the mill could use the rotational force of the flywheel directly.
I would like to see you stop and back it up should a stone, dog, wife or other object gets past the hopper?
This makes me think of the movie "Fargo" for some reason.
 

Catt22

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I would like to see you stop and back it up should a stone, dog, wife or other object gets past the hopper?
This makes me think of the movie "Fargo" for some reason.
A simple clutch mechanism could be configured and, of course, proper shrouds and guards. I think if anyone got caught up in my current mill w/gearmotor that the mill would not stop until it reached maybe your shoulder. It can be switched off, but a lot can happen in the second or few that it might take to reach the switch. I never get close to the rollers at all when it's in operation and I unplug it completely if I do any work on it. Even a drill motor can be hazardous, especially the high torgue half inch or larger drill motors. I've tangled with a few of those over the years. I pay attention to safety. Everyone should.
 

BrewBeemer

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A simple clutch mechanism could be configured and, of course, proper shrouds and guards. I think if anyone got caught up in my current mill w/gearmotor that the mill would not stop until it reached maybe your shoulder. It can be switched off, but a lot can happen in the second or few that it might take to reach the switch. I never get close to the rollers at all when it's in operation and I unplug it completely if I do any work on it. Even a drill motor can be hazardous, especially the high torgue half inch or larger drill motors. I've tangled with a few of those over the years. I pay attention to safety. Everyone should.
Ya, ya! As in Fargo.
You must also add a a rev limiter, minimum rpm's as well a torque meter to your system with a recorder to read back your grain crushing data for downloading to your processor. LMAO, JK'ing there Catt22.
 

Catt22

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I just wish I lived where I had a decent stream running through my property. I would build a water wheel to power the mill.
 

BrewBeemer

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I just wish I lived where I had a decent stream running through my property. I would build a water wheel to power the mill.
A 30' diameter overshot waterwheel would add the old world charm to the ZBier Garden unless you think your a "Green" person and went solar, all drinking in ther daytime only now that would suck. Hell knock down one of those emergency roadside call boxes for the solar collector with charging and battery system.

I have a Sioux 3/4" chuck "D" handle drill motor with a unloaded speed of 325 RPM's, there is a reason for the 3/4" female thread for adding a long handle onto the motor. It will eat a shoulder joint in an instant.

Step it up an bit, I have one of these complete sets with all the dies, http://www.drillspot.com/products/63368/Ridgid_700_Thread_Drive, it is 1/2 hp at 32 RPM's No Load. Great for digging well also. Just need to add 30" of 1" steel rod and a bicycle grip to extend the handle. An animal but not cheap and a needed tool in the trades especially with the 15/16" square drive adapter. It will shear off a 15/16" HR Steel square drive, also take you for a ride over the Tri-Vise threading 2" with dull dies.
 

BrewBeemer

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Here's a picture of my recent build. I used the motor off an old dryer I had in the barn. Works nice and slow also. I seem to have increased my efficiency from 70 to 80% since using the motor instead of my variable speed drill.
It does require a little kick start to get the mill going, but once moving there's no stopping it (except with the switch!)
That belt sure looks loose besides a miss match with the pulley on that motor looking like a "A" size pulley with a size "B" belt plus the large pulley is only half on the mills shaft due to the hoppers flare adding uneccessary bushing side loading. Any belt slipping problems like the smell of burning rubber running the wrong size motor pulley with too loose of a belt?
 

Cape Brewing

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Who's going to be "green" and simply hook the mill up to the back of a stationary bicycle??

Peddle away the calories you're going to take in once the beer is done!!
 

Laughing_Gnome_Invisible

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Who's going to be "green" and simply hook the mill up to the back of a stationary bicycle??

Peddle away the calories you're going to take in once the beer is done!!
Dammit!! We just gave ours away!!! That would have worked for me. I woulda done that!!! :mad:
 
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