Motorizing my Barley Crusher - Home Brew Forums
Register Now For Free!

Home Brew Forums > Home Brewing Beer > Equipment/Sanitation > Motorizing my Barley Crusher

Thread Tools
Old 02-14-2008, 06:14 AM   #1
It's a sickness!
Gabe's Avatar
Apr 2006
Central coast
Posts: 715
Liked 2 Times on 2 Posts

Looking at McMaster-Carr's' part# 6142K72 AC electric gear motor. 115 volt, 150 RPM. They say it has 5lb's torque. Is that enough to effectively crush my malt? I plan on using sheaves and belt and building a mobile, motorized grain mill. I just want to pick the right motor the first time.
Cheers, Gabe

Reply With Quote
Old 02-14-2008, 02:52 PM   #2
conpewter's Avatar
Nov 2007
East Dundee, Illinois
Posts: 5,109
Liked 54 Times on 49 Posts

I don't think that will have enough torque but I could be wrong. You could get a different motor with a higher rpm and gear it down.

I run my mill with a corded drill and I've seen several others with this setup. From a little research i've found that cordless drills have somewhere around 450 in-lbs of torque (so corded would be the same or more). 450 in-lbs may be overkill for most mills (I don't have a barley crusher) but I just don't think that 5 in-lbs is going to be enough. Consider how much that really is, that's a 5 inch bar with 1 lb on the end of it, not a lot of torque at all.

Reply With Quote
Old 02-14-2008, 03:13 PM   #3
abracadabra's Avatar
Dec 2006
Newnan, Georgia
Posts: 1,923
Liked 8 Times on 8 Posts

How many amps is the motor? Or how much horsepower?

I'd think 5 ft./lbs of torque might do. But most people use a small sheave 1/2" on a motor that runs approx. 1850 rpm and a large one 10" on the grain mill to acheive approx. 300 rpm on the grain mill.

So you'd have to have the larger sheave on the motor and the smaller on the grain mill to get your RPM up to 300.

If it were me I rather go with the conventional setup rather than try to reinvent the wheel.

here's an example of one from BYO using a 1/3 hP 1750 rpm motor to drive a grain mill at 185-200 RPM.
Do what you like!
Brew what you like!

Reply With Quote
Old 02-14-2008, 05:55 PM   #4
HenryHill's Avatar
Mar 2007
Perry, MI
Posts: 3,040
Liked 11 Times on 11 Posts

I think you are confusing the two common ways of powering a mill.

Many use a medium size electric motor and pair of sheaves or pulleys, with a v-belt. This 'gears down' the out put speed from around 1700 to whatever you are aiming for; generally around 200-250rpms. using this speed reduction system also increases the usable torque of the motor, like any transmission system does.

Others use an AC gearmotor to direct drive the mill by way of a flexible coupling. The speed reduction system is built into the motor by way of a gear reduction system on the output end of the motor. These are rated by rpm and out put torque although they also are commonly rated by hp, too.

I have seen recommendations of 1/3 hp and around 50 in/lbs of torque, although pinning this down exactly is open to variables such as how long the mill rollers are and what type of power is being used to run the mill.

Bodine gearmotors are popular due to the variety and availability.

I used their website to plan my mill station.

I was interested in the 42R-E Parallel series. I think the 48R-F series is a bit of overkill.

I was aiming for a 115 rpm motor, with 68 in/lbs., #0651, but chickened out on bidding, then found the 0650 @170rpm and 45 in/lbs., new, for a buy it now price and jumped. It is a very substantial motor and I believe it will work fine although I have to buy my mill yet. It is much more substantial than a cordless drill... I have powered it and it is impressive. It does not require an additional capacitor, as many do. I still need to build a stand and wire it, but it's been ambition-killing cold around here for quite a while...

Many are currently searching for gear motors, so competition is tighter than it used to be but I got a new Bodine for $59. List = $312.

IIRC, the BC is a short roller mill and since less grain is going thru it at one time, than say, a longer roller type, like C&S and Monster, you should be able to get away with a proportionally smaller amount of torque than those other mills.

-Won't direct display-
Originally Posted by orfy
Never mock another man's brewery.
Originally Posted by IrregularPulse View Post
This is HBT of course. Normal Thread that goes every direction but the one intended. This forum should be scientific proof the beer causes ADD

Reply With Quote
Old 02-14-2008, 06:10 PM   #5
mr x
May 2007
Mainly Halifax
Posts: 1,576
Liked 4 Times on 4 Posts

My Bodine motor is rated in Nm at 6.2 which is 4.57 ft/lbs. I have it hooked up to a Crankandstein 3 roller mill. This runs at about 100 rpm. It will destroy anything except rocks and steel.
This place really went to hell. Follow the OF standard stout. Bye.

Reply With Quote
Old 02-14-2008, 07:54 PM   #6
conpewter's Avatar
Nov 2007
East Dundee, Illinois
Posts: 5,109
Liked 54 Times on 49 Posts

Just to clarify he means 5 in-lbs. If you go to McMaster and look up the part you'll see that in it's rating. I definitely agree that a motor with 5 ft-lbs of torque would work great (at the right rpm)

Reply With Quote
Old 10-15-2008, 11:56 PM   #7
Jan 2007
Jackson, GA
Posts: 35

Dan's Motorized Grain Mill

Reply With Quote
Old 03-30-2015, 01:58 PM   #8
Mar 2015
Cape Cod, Mass
Posts: 5
Liked 1 Times on 1 Posts

Did you end up building your mill with eh 42R-E motor? How does it work? Any suggestions or hindsight style insights? Trying to build out a Barelycrusher for my local homebrew shop.
Proud customer of New Farm Homebrew Supply Cape Cod, Orleans, MA and recording the tales of all things fermentable at

Reply With Quote
Old 04-10-2015, 07:14 PM   #9
Apr 2013
Posts: 913
Liked 161 Times on 137 Posts

I just picked up this motor off of eBay. I'm hoping that it will workout for motorizing my barley crusher. I need to get a 3/4" to 3/8" lovejoy coupling (I believe the Barley crusher is 3/8").

This was the description of the motor:
MODEL MGA - 02525
RPM 230
Motor length 10 1/4" 5" diameter
Shaft 1 5/8" long 3/4 " diameter
Click image for larger version

Name:	motor_57.JPG
Views:	405
Size:	234.9 KB
ID:	270168  

Reply With Quote
Old 05-20-2015, 09:14 AM   #10
Junior Member
chiefairwrench's Avatar
Dec 2012
Atlanta, Georgia
Posts: 238
Liked 37 Times on 29 Posts

Is the barleycrusher 3/8 shaft for the love joy? I like to order mine today

Reply With Quote
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Motorizing my Barley Crusher RobertHSmith DIY Projects 23 10-02-2013 11:19 PM
Barley Crusher PavlovsCat All Grain & Partial Mash Brewing 14 11-13-2010 02:45 AM
What's your gap on your barley crusher? Yooper Equipment/Sanitation 42 08-05-2009 07:42 PM
Barley Crusher on the way plumber All Grain & Partial Mash Brewing 4 01-19-2008 02:46 PM
Barley Crusher davidkrau Equipment/Sanitation 4 04-12-2006 02:54 AM

Forum Jump