Motorizing a grain mill . . . . . . without a drill

[rushrich]

I am looking to create a motorized grain mill and attach it to the top of an existing cabinet that is on casters.

While I have seen motorized grain mills that either run on hand drills or are belt driven. . . I am trying to see if there would be a gear box that I could attach either inside or outside that could work.

I am not very mechanically inclined, which only adds to the problem, but I am concerned about finding something that will work, is not that hard to setup and will not be dangerous (won't small grain particulate get into the gearbox or do they make some that withstand particulate without the risk of fire/explosion/no fun times?)

In summary

1. What grain mill do you think works the best and why?

2. How can I motorize a grain mill easily without a drill?

Thanks in advance!!!

[Frank]

I am with you Rich. If you come across a deal on 2 of something you only need 1 of for your motorizing process pick it up. I'll be in for it.

[ParkerBrew]

That's also on my list of things to do sometime in the future. I was planning to use a motor out of an old piece of woodworking machinery; table saw, band saw, drill press, belt sander, etc.

I've heard the 3-roller mills are the way to go.

[Rugger1978]

I motorized my grain mill and love it. Just need to find you a gear motor that has an rpm of 100 to 200 and a minimum of 30 in-lb torque. You could do as low as 16 in-lb but you would have to have the mill running before you added grain as you wouldn't have enough torque to start once grain is in between the rollers. Once you have the motor and know it's shaft size, go to McMaster-Carr and order spider couplings (also known as lovejoy connectors). You'll need to order 3 pieces: the coupling that goes on the shaft of your motor, coupling that goes on the shaft of the grain mill, and the correct size spider coupling. Note that the shaft on the motor could be a different size then the grain mill, so you might have to buy couplings with different size shaft holes, but make sure they both use the same size spider coupling. Then it's a matter of some simple wiring and installation. I documented my build on my brewing Facebook page.

McMaster-Carr "lovejoy" connectors:

http://www.mcmaster.com/#catalog/119/1171/=m8fbmh

My Fat Back brewing motorizing grain mill documented:

https://www.facebook.com/media/set/?set ... 055&type=3

[Sláinte!]

I motorized my grain mill and love it. Just need to find you a gear motor that has an rpm of 100 to 200 and a minimum of 30 in-lb torque. You could do as low as 16 in-lb but you would have to have the mill running before you added grain as you wouldn't have enough torque to start once grain is in between the rollers. Once you have the motor and know it's shaft size, go to McMaster-Carr and order spider couplings (also known as lovejoy connectors). You'll need to order 3 pieces: the coupling that goes on the shaft of your motor, coupling that goes on the shaft of the grain mill, and the correct size spider coupling. Note that the shaft on the motor could be a different size then the grain mill, so you might have to buy couplings with different size shaft holes, but make sure they both use the same size spider coupling. Then it's a matter of some simple wiring and installation. I documented my build on my brewing Facebook page.

McMaster-Carr "lovejoy" connectors:

http://www.mcmaster.com/#catalog/119/1171/=m8fbmh

My Fat Back brewing motorizing grain mill documented:

https://www.facebook.com/media/set/?set ... 055&type=3

^^What he said. Toolman may be able to provide advice on motor/controller combinations that allow smooth ramp up to operating RPM.

Rugger - What is your source for the minimum 30 in-lbf torque value? Did you measure & calculate it yourself, read it somewhere, etc?

[Rugger1978]

It was a number that a few people around on the web calculated. With all the research I did before I built mine, I read time and time again people's accounts of motorizing their own grain mills and each time, if they had a motor down on the low range of torque, they couldn't start it if grain was already in it.

However, you can do the calculation yourself to determine how much your grain mill with it's gap setting needs. Put some grain in your mill and hang a bucket from the handle. Then start adding water to the bucket till it moves. Weigh the bucket and measure your handle length in inches. Multiply the two together and that will give you your MINIMAL lb-in needed to start your mill when grain is in it.

Cheers!

[Sláinte!]

It was a number that a few people around on the web calculated. With all the research I did before I built mine, I read time and time again people's accounts of motorizing their own grain mills and each time, if they had a motor down on the low range of torque, they couldn't start it if grain was already in it.

However, you can do the calculation yourself to determine how much your grain mill with it's gap setting needs. Put some grain in your mill and hang a bucket from the handle. Then start adding water to the bucket till it moves. Weigh the bucket and measure your handle length in inches. Multiply the two together and that will give you your MINIMAL lb-in needed to start your mill when grain is in it.

Cheers!

We use a corded drill to run our mill and haven't talked seriously about semi-permanently motorizing it. It's good to know there seems to be some test data behind the minimum recommended torque value though.

There are two additional procedures that should be followed when testing for the minimum required torque value:

1. Since the vertically downward pull of gravity is being used to exert the load on the mill's handle, the handle should be as close to horizontal as possible. A slight angle is okay, but the error compounds quickly if it's more than 15° from the horizontal. It is an error in the conservative direction though.

2. The hopper should be full of grain when testing. This is more important if you have an expanded hopper that is quite tall.

Also, to expand on what Rugger1978 said, the mill's gap needs to be set properly before testing. If you test and calculate your torque value based on rollers that are set too wide and buy a motor with similar output, your motor might not have enough torque to mill in all situations when the rollers are moved closer together.

[rushrich]

All excellent answers. Thanks!

What brand/model of mill does everyone have?

Is three rollers better than two?

[Rugger1978]

Or you can just over kill it like me and never worry about it. The motor I got is an 150 rpm and 180 in-lb of torque! LOL. I just hope I never get a rock or anything in my grain, it would probably f up my rollers....


There is much debate about 2 rollers vs 3 rollers, but in the end 2 rollers are going to get the job done with ease and I don't see a reason to move to 3. Pretty much all the grain mills on the market today are good quality. It really like a Chevy vs Ford thing, hehe. I personally have the JSP Maltmill AA which is adjustable on both ends and comes with a small hopper by default . It's been great and I have no complaints, however if I were to do it over, I'd probably get the single side adjustable with the gear drive option as it would probably work a little better motorized. I know a lot of other people use Monster mills or the Barley Crushers, but in the end they are all pretty much the same, imo.

[Matt]

Motorizing my mill has long been on my To Do List also. But finding a motor with the desired low RPM and high torque has proven VERY difficult without spending a ton of money. I too would rather do a spider/lovejoy coupling than set up flywheels and belts, so please let me know if you come across something suitable.

If there are a few available, maybe several of us can go in on a bulk order and save on the shipping, which will be significant given their weight.

Matt

[Matt]

Jared, what is the make and model of your motor? Can anyone who's direct-driving their mill give us some makes/models/part numbers to search for?

Thanks

[kevputo]

I came across Oriental Motor when I was looking awhile back. They have some as low as $155 with free shipping.

Here's one rated for 37in-lbs & 100rpm: http://catalog.orientalmotor.com/item/a ... id=3001023
And another rated for 30in-lbs & 120rpm: http://catalog.orientalmotor.com/item/a ... id=3001023

FWIW, I eventually decided to keep using my $20 Bargain Depot drill.

[Blktre]

You want the beefy bodine. Add a coupler and a start cap and in business for cheap money.

http://www.herbach.com/Merchant2/mercha ... y_Code=MTR

[Rugger1978]

I purchased a Bodine ECI-582E2 154 RPM 180 in-lb torque motor off of ebay. I had contacted Bodine with help on wiring and during the process they told me that it was a custom made motor for Zerox. I paid $125.00 for it. Damn thing cost me as much as my grain mill, but it mills 30lbs of grain in less then 10 minutes.

[Blktre]

I purchased a Bodine ECI-582E2 154 RPM 180 in-lb torque motor off of ebay. I had contacted Bodine with help on wiring and during the process they told me that it was a custom made motor for Zerox. I paid $125.00 for it. Damn thing cost me as much as my grain mill, but it mills 30lbs of grain in less then 10 minutes.

About 10yrs ago the Bodine I posted was all the rage. Only $18.00. A lot of mills out there use it. I don't own one but people still like them so I've read over the years.