Motorizing a DIY Grain Mill

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JayZeus

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Hello,

I am thinking about motorizing my DIY grain mill but I have no idea where to start on motor selection.
What's a good HP? RPM? What size pullies should I go with?

Any advice is appreciated.
 

day_trippr

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RPM should be in the 150-200 rpm range for speed vs minimizing dust production. Torque should be a minimum of 50 inch pounds for a two roller mill, 75 for a three roller. Higher doesn't hurt :) I would avoid using pulleys and a belt if possible for hazard reduction. Also side-loading roller bushings will shorten their lifespan; not really an issue with true bearings. If one has to go with belt and pulleys you typically look for a 1:10 size ratio of drive vs driven pulleys, as most single-phase induction motors spin at 1800 rpm...

Cheers!
 

spittybug

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Have you considered just using a power drill? I use my Porter Cable and grind 25lbs of grain for brew day in about 5 minutes. My mill is mounted to the top of a big bucket and I then just pour it into the mash tun. Easy peasy, cheap and quick.
 

IslandLizard

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RPM should be in the 150-200 rpm range for speed vs minimizing dust production.
rpm depends on the diameter of your rollers.

From my notes:
"For grain used in brewing a linear mill speed of around 12"/sec (ips) is recommended. IIRC, I got that on a pro forum."

That translates to:
For 1.5" diameter rollers 152 rpm
For 2.0" diameter rollers 115 rpm

I use an older model high torque, low speed drill (550 rpm max) from Harbor Freight. Once milling, under load, with about half its power on the trigger, it runs at around 150 rpm on my 1.5" MM-2.
 

jerrylotto

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I built one using a washing machine motor. Motor speed is 1152 RPM so I wanted to drop it 10 to 1. Best I could find was 8 to 1 but it works fine. I added a right angle elbow so that I could direct the grist to the side. Picture isn't great but I think it'll give you the idea.
 

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Dr_Jeff

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I built one using a washing machine motor. Motor speed is 1152 RPM so I wanted to drop it 10 to 1. Best I could find was 8 to 1 but it works fine. I added a right angle elbow so that I could direct the grist to the side. Picture isn't great but I think it'll give you the idea.

When Halloween comes around, pick up a rubber hand and pull off a couple of the fingers and tack them in place with a brad gun along with a bit of red paint near the pulley.
 

jerrylotto

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When Halloween comes around, pick up a rubber hand and pull off a couple of the fingers and tack them in place with a brad gun along with a bit of red paint near the pulley.
OSHA got no hold on home brewing! I would not only need a pulley guard, they would make put chicken wire on the hopper and enclose the whole base,
 

BFD_BrewGeek

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