Help with Motorizing a Grain Mill

[two_barking_dogs]

Hi,

I have a hand cranked grain mill which also has a pully attached. I like to power the mill with an electric motor but I don't know much about them or what to look for.

My thinking is that I would have the motor attached to a dimmer switch, say 600 watts, to allow me to control the speed of the grind. The pully on the mill is about 12" across so I was going to get a smaller one, 4", for the motor side. The motor and mill would be connected by an auto fan belt.

I have a Grainger near work so was looking through their website and saw the below. I choose these because they have a mounting base built in where as a washer motor I have doesn't and thus leaving me unsure how to mount it.

Since they are so much money I'd like to do this right. Any suggestions are welcome.

Thanks


Motor,1 HP,Farm Duty

http://www.grainger.com/Grainger/items/4K124


Farm Duty Motor,1 HP,1725,115/230v,56H

http://www.grainger.com/Grainger/items/1TMY5


Farm Duty Motor,3/4 HP,1725,115/230v,56

http://www.grainger.com/Grainger/items/1TMY4


Motor,1/2hp,Farmduty

http://www.grainger.com/Grainger/items/4K123

[Blu3duk]

I personally would not use a rheostat as you want full power on the unit at all times. What size motor does the manufacture suggest? and speed? and then what recomended size pulley on the motor? if you dont have that information what type of grinder is it you have and what size flywheel is on it?

William
Idaho

[farminghandyman]

look up the manual and follow the directions it has for horse power and pully size and and speed,

[Beeman]

Speed is the first thing you need to know, then you can choose a pulley for the motor. Don't use a speed control just run the motor at a constant speed. Mount the motor on a hinge type setup so the weight of the motor holds tension on the belt. I'd bet an old washing machine motor would work fine.

WOW!, I just looked at the price of those motors!. Check your area for a used appliance shop or a metal salvage yard. Used motors are cheap and a small motor like that should be easy to find.

[ace admirer]

the variable resistor (i can't spell reostate) will not work well with an induction motor, it will with a universal motor. is it a modern or old grinder? it should not take much hp perhaps 1/2 not much more. i think i have one from northern tool that has a crank handle that is mounted to a v belt sheave. its about 12 inches in diameter. a fractional belt (L series) or perhaps a size A belt would do. like others have said,,,check the directions. seems around 250 rpm would be about right,,,,but thats a guess

[clovis]

I too would check out any place that scrapped washing machines and dryers. Our local new appliance place scraps LOTS of trade-ins. The will actually give you the unit if you agree to haul it off.

Know any scrappers? They would be an excellent source for used motors.

Ebay would be a great place to check. I am stunned at the cheap prices on used motors at times.

You could place an ad on craigslist looking for a free motor, or join up with your local freecycle group.

Do you have any janitorial dealers in your area? Those that sell and service large cleaning equipment may have something for you.

I would also call Heating and Air contractors. They would most likely have motors from furnaces and AC units that are being changed out.

I hired a guy to change my furnace out this year, and the motor already had a bracket on it.

If you found a free used unit, so what if the motor only lasted a few years?

Clove

[Batt]

All my research said that about 110-120 RPM on the grinder was about right. As I recall I used about a 1 1/2" pulley on an 1100rpm 1/3 hp motor and a 13" Dia.pulley on the grinder. Seems to work great so far, but it has only been about a year.

Hmmm... 1 1/2" pulley = 4.71" per revolution x 1100 rpm = 5181 inches per minute.

13" Dia. * Pi = 40.84 " per revolution

5181"/40.84" = 126.8 rpm on the driven pulley

[Old Vet]

You can get a lot of revolutions per minute from several motors. I would get a 950 revolutions per minute and use the same formula that Adron used and get one that would turn much slower.

[agmantoo]

You are getting ahead of yourself IMO. Most of those hand driven grain mills do not have bushings(bearing) in the housing and any major side load will wear the unit out quickly. A means of lubricating the shaft would also need to be considered. It would be best to drive the grain mill slowly, maybe 3 times hand speed and to let the grain feed into the unit gradually. A gear reduction drive motor with a coupling to align the grain mill shaft to the gear motor should be the drive mechanism. This would avoid the side loading and add life to the device. There are surplus sources for such gear reduction motors. Here is a motor that could be used but you still need to address the side loading IMO. You cannot beat the price!
http://www.surpluscenter.com/item.as...-1677&catname=
This is a pic of the type coupling you need to consider
http://www.coleparmer.com/catalog/la...mg=07127AF.jpg
Here are the prices for the coupler
http://www.coleparmer.com/catalog/pr...sp?sku=0712769

[two_barking_dogs]

Thanks for all of the replys

To answer some of the questions I do not know what brand the grinder is and have no directions, It is similar to a CSBell model #60 if that helps, image of CSBell model below. The CSBell website says that theirs runs at 450 rpm and can be powered without issues. This unit has a pully with a v-belt channel built into the hand crank thus it would also seems to be set up to be powered.

I was thinking of using a speed controler so as to keep me from doing the math that Adron posted, thanks, as once I had the grinder set up under power I was also going to do a hand cranked corn sheller using the same motor and wanted to insure that I could control the speeds independently without swapping pullys if that makes sense. I know that there are some motors which can be controled with a dimmer switch as my wholehouse fan is set up that way and has been working for at least 15 years. However my wholehouse fan motor did not have a plate on it for me to steal the info from.

For speed of grinding, etc, I'd be happy with hand cranked speeds. Its just that even with 2 people it would be nice to be able to not have to turn the crank as there are tasks like supplying grain or removing the ground grain that need to happen during the grind.

Yes the prices of motors at Graingers are high and I was hoping I don't end up buying from them but I started at their website cause they have a big selection on their site and they have a location down the road from my work. My problem is is that I don't know the buzzwords on electric motors nor what to look for in what I need for my usages.


Thanks for all of your help

[HermitJohn]

I dont think you want shaft on mill turning over 50rpm unless your mill's manufacturer recommends faster. If you need higher production, better to get bigger mill than trying to turn small mill faster. You shouldnt need 1hp motor especially when you are gearing down the speed to such an extent. I'd say a 1/3 to 1/2 would be fine and you probably could even go lower if you found a deal, especially if you gear down to turn mill at 40 to 50 rpm. Look at Burdens out of Lincoln, NE. http://www.surpluscenter.com/ They tend to have some oddball rpm motors cheap. They dont work well for applications designed for standard rpm motors, but since you are custom gearing your mill, it doesnt matter.

[Jackpine Savage]

Here is one idea that I ran across awhile back. It addresses Agman's concerns about sideload: http://hbd.org/rlaborde/maltmill.htm

[freelove]

This page has information on exactly how to motorize a grain mill. Scroll down past the products that they sell.

http://www.countrylivinggrainmills.c...ction=motorize

[two_barking_dogs]

Thanks for your alls help on this. I have not figured out yet how to step down the speed low enough without using a speed controller but I have some ideas on the overall design.

Surfing the net I have not yet found motors which have an RPM of less then 1750. And I'd like the final RPM to be approx 50 which I think is hand cranked speeds. This I think will require a series of pulleys -vs- just the motor and mill pulleys.

And I think I'm going to put the word out at the dump that I'm now collecting washing machines to see what I can come up with although I'll keep an eye on surpluscenter to see what they have. I've been wanting to get to the dump as I'd like to try my hand at building a wizbang plucker and was going to try a washer tub to start.

Again thanks

[artificer]

Take a look at this gear-motor from Surplus Center

68rpm, 1/10hp

Michael

[HermitJohn]

Originally Posted by two_barking_dogs

This I think will require a series of pulleys -vs- just the motor and mill pulleys.

Yes standard rpm motors you will need a jackshaft turning in pillow blocks. Small pulley on motor to large pully on jackshaft. Small pulley on jackshaft to large pulley on mill.

Hmm, dont know about 1/10 horsepower even geared down. then again when OEM motor went on my old wringer washer, I substituted a 1/6 hp motor I had setting around until I could find one same size as original and it seemed to do just fine. Never had it bog down. Cant remember now what OEM motor was but seemed like it was 1/3hp but maybe only 1/4 hp.

[ace admirer]

i've got a few of the bells on antique and hit and miss engines. the speeds are not too critical. the antique bells that i have have a steel shaft running in a cast iron housing, heavy oil was used for lub. THE CRITICAL thing on the bells are that they are metal burrs. if the burrs ever come in contact with each other on a motor driven unit.....well its kinda like a small train wreck...you will probably have to purchase new burrs.

you can always run an intermediate shaft to slow the cheaper 1745 motors down to the couple of hundred rpm for the mill, but if you can find a 14 or 16 inch pulley: so 14 inch mill sheave x 300 mill rpm / 1745 motor rpm = 2.4 dia motor sheave. kinda small but a fractional L belt might bend around a motor pulley that small. i've seen some run using a stepped cone pulley for the intermediate shaft.. motor belt to the large cone, small cone to the large mill pulley like others have posted, hard to beat surplus center for prices.

[agmantoo]

Did you look at the $10 motor at the link I posted. That motor and a coupling would let you drive the mill with no side torque.

[clovis]

I think I would look at Agman's $10 motor. Looks like a super good deal, and a great idea.
Clove

[solidwoods]

DC gearmotors have low rpm and high torque.
They also can be controled by a rehostat to allow rpm adjustment.
jim