Motorize your grainmill for under $100

[simba123]

Folks,
I wished about motorizing my grain mill for a long time. Finally got it done.

Components:
$45 - Broan Attic Fan motor(1140 RPM, 120V) - Amazon
$25 - 12" inch v-belt pulley(Mill side) - Ebay
$10 - Plywood board or Cutting Board that is lying around
$6 - 2" inch v belt pulley (Motor side) - Ebay
$1 - Home depot bucket lid washer for belt
$10 - Misc, Screws, switch, cord etc.

Hopper is custom made with salvaged wood,
Mill is Crankandstien 2S 5" mill.

Grain milling was excellent with about 180RPM. Maybe a little slow but it took about 1 minute per 8 pounds. Way better than manually holding on to a drill that smells burnt!

Use 10” pulley for faster speed.

Cheers!

 

[Morrey]

Sweet! You say 180 rpm is a bit slow. I believe 180 rpm to be the ideal sweet spot for a good grind. Great job...perfect!!

 

[Smellyglove]

It depends on the diameter of the rollers. Nice build!

 

[HausBrauerei_Harvey]

looks great

 

[Gadjobrinus]

Very clean! Don't know how you'd do it, but have you thought about putting a drive belt cover of some sort, galvanized maybe?

 

[Parrothead01]

Nice

 

[MaxStout]

I did the same thing for my MM. A 1/4HP motor, 1.5" pulley to 10" pulley. Drops it to about 250RPM. There are times I wish it were a bit slower (i.e., crushing hard grains like wheat). So 180 RPM is about right, IMO.

Nice job!

 

[simba123]

Don't know how you'd do it, but have you thought about putting a drive belt cover of some sort, galvanized maybe?

Why would I need this? for safety?

 

[Gadjobrinus]

Why would I need this? for safety?

Yep. I've seen a lot of farm accidents. They're not pretty.

I've also seen what happens when a 12 year old drops a rope between the bed and the cab of a 1-ton truck, to watch the rope dance on the driveshaft. All 3 arm bones snapped in two, arm almost torn off at the root, wide scarring over the whole arm to this day. 3 guesses who the genius was.

Yep, big fan of covering moving things, when possible.

 

[MaxStout]

Yep. I've seen a lot of farm accidents. They're not pretty.

I've also seen what happens when a 12 year old drops a rope between the bed and the cab of a 1-ton truck, to watch the rope dance on the driveshaft. All 3 arm bones snapped in two, arm almost torn off at the root, wide scarring over the whole arm to this day. 3 guesses who the genius was.

Yep, big fan of covering moving things, when possible.

I doubt OP's 1/4 (or so) horse motor could inflict anything near the same kind of damage a truck driveshaft or farm equipment could do. Sure, someone could get a nasty pinched finger or shirt tail caught in the works. But, I agree with you about the need for some kind of cover. A piece of sheet metal, some wire mesh, etc.

 

[Gadjobrinus]

Sorry Max, yes, of course I agree. Just trying to say, it wouldn't be fun and I do think a general practice should be to have in place a guard over any pulley system.

 

[MaxStout]

Agree. Even pinched fingers can be very painful, and these mills are certainly not without danger. Any time you can cover rotating machinery, you're adding a good layer of safety.

My mill's drive system is almost identical to OP's. I wasn't paying attention and caught my index finger in the big pulley of mine once. The v-belt was not tight, so the wheel stopped turning and the belt slipped. I was able to quickly switch off the motor and the only damage was some abrasion burn where the pulley and belt rubbed over my skin. A few choice words were uttered. Luckily, my finger didn't get pulled through the pulley which would have been much more painful. I don't have a cover, but I turned the mill so that the pulleys are on the far side from me and facing close to a wall. The pulleys are out of my reach. Still, I need to fabricate some kind of cover.

 

[Gadjobrinus]

Yikes. Glad that was it, Max. Yep, I'm the moronic kid who was playing watching a rope dance on the drive shaft and snapped every bone, nearly lost my left arm at the shoulder. I also saw so many industrial accidents while working in Chicago. So, I have to admit, it freaks me out and just don't want to see anyone hurt...nasty!

 

[seckert]

Following this build as I need a motorized mill. I say this after milling over 19lbs of grain today to brew...haha

 

[Mr_McGibblets]

Nice build!

Personally, I'm very limited on space and don't like the idea of an exposed belt.

So I built this custom board and use an adjustable zip-tie wrap thing to keep my drill running at the preferred speed.

Did it a few weeks ago for my first all-grain brew.

 

[LavaSteam]

great build Simba123.
question for Mr. McGibblets; How can one tell how fast ~180 rpm is with your drill? I also use a drill to power my mill and just have to guess at the rpms. I like your yellow speed control device. I tried using a c-clamp but it slips off all the time.
cheers

 

[gnor]

What is the distance between the mill rod and the motor rod?

 

[hawaiibrewer]

A hand drill just didn't cut it for me...tried a battery operated as well as a 110v corded drill. Both were too hard to regulate speed and got too hot when grinding my 28 lbs of grain. Went to my local "dump" where old appliances are dropped off with my wrenches in hand and salvaged a nice Whirlpool 1/2hp washing machine motor. Gave the guys $5.00(they wanted nothing). The most costly items were the pulleys as shipping to Hawaii is terrible. I have about $130.00 in the mill including the rollers. I kept the original hopper as I just don't need to load 28 lbs and walk away without watching to make sure no foreign objects are in the grain. I chose not to add a pulley guard as it would just add weight and bulk up the mill.....and I'm a big boy that can keep my fingers out of the belt. FYI...my motor I salvaged was from a 3 speed washer so I wired it to run on the slowest speed, hence no need to use such a large pulley to slow it down.

 

[johnzbesko]

For the longest time, I wanted to motorize my mill. Could never figure out where or how to get pulleys to drive it.

Settled on a 1/2" electric drill controlled with a "desktop dimmer". Used a plastic kitchen cutting board for the base.

 

[Mr_McGibblets]

great build Simba123.
question for Mr. McGibblets; How can one tell how fast ~180 rpm is with your drill? I also use a drill to power my mill and just have to guess at the rpms. I like your yellow speed control device. I tried using a c-clamp but it slips off all the time.
cheers

Mark the drill chuck with a piece of masking tape or something, then adjust accordingly until you watch it go around roughly 3x per second = 180 rpm.

I used to be a DJ, so counting "180 BPM" is pretty natural for me.

Or, you could just play one of these songs and have the drill spin to the beat, LOL!

https://www.verywell.com/running-songs-at-180-bpm-2911509 :rockin:

 

[hawaiibrewer]

The distance between my motor pulley and mill pulley is about 16 inches, but pretty much what determined that was the fact that I wanted to put a specific size bucket under the mill to hold my typical 28 lbs of grain. I used a piece of measured rope around the pulleys to determine the needed belt length then went to my local auto supply to buy the belt. I use the 2 wing nut controlled threaded rods which are attached to the motor to adjust the belt tension by pulling or loosening the motor.

 

[augiedoggy]

I use an old blueprint machine motor for mine gear reduction and 110v dc... very powerful but a bit slow (hence the pulley arrangement to get some rpm back) I built a cheap ac to dc variable voltage power supply to power and control the speed with a wall dimmer switch and $3 bridge rectifier mounted to a heatsink. going strong for 3 years now.

It should be mentioned that for pulley drive setups, the real ball bearing in the cereal killer as well as the kegco 3 roller I just purchased are ideal for sideloaded pulley configurations vs bushings that will be more prone to wearing out quickly this way. For bushing mills lovejoys or drills are ideal. MM also does also offer bearing in at least one 2 roller pro version of their mills and they currently call it the "pulley drive option"

 

[SleepyCreekBrews]

I like that hopper man.
I'd be willing to bet many of us probably own a cordless drill that no longer holds a charge and is only good for drilling a single hole or two before it's dead. I had a Hitachi 3/8" VSR, dual-speed drill that I used for mine. It has a selector switch on the top for Low-speed/high-torque (400 rpm), or regular speed (1700 rpm) . I connected a 12DVC power supply to it and set the trigger for ~150 RPM , ...Hard to beat a motorized grain mill, eh Simba?

 

[simba123]

Thanks for all your comments guys! Yep this is really helping, 28lbs grain was taken care in few minutes. My IPA is in the fermenter now. 1.075 OG, 1.014 FG. Just dry hopped it. Will post an update soon.

I am having the fly wheel towards the wall for now, not super safe but OK.