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Convert large fan for use with grain mill?
- Thread starter shetc
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Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:
I think the tricky part would be attaching fan blades to the grain mill in order to receive the windy blast produced by that fan. 
Just for the motor, right? And it looks very big!
You will need pullies or a gear reducer to get the speed down to where your mill will be happy.
For grain used in brewing a linear mill speed of around 12"/sec (ips) is recommended.
For example, using a 1.5" diameter roller mill (e.g., an MM2):
Roller circumference = 1.5" * 3.14 = 4.71"
12 ips / 4.71" * 60 sec = 152 rpm < that's the target speed for driving the mill.
Many such motors are in the 1750 rpm range, IIRC, but double check, there should be a plate on it with those specs.
120V? 240V?
You will need pullies or a gear reducer to get the speed down to where your mill will be happy.
For grain used in brewing a linear mill speed of around 12"/sec (ips) is recommended.
For example, using a 1.5" diameter roller mill (e.g., an MM2):
Roller circumference = 1.5" * 3.14 = 4.71"
12 ips / 4.71" * 60 sec = 152 rpm < that's the target speed for driving the mill.
Many such motors are in the 1750 rpm range, IIRC, but double check, there should be a plate on it with those specs.
120V? 240V?
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I don't know what size the grain mill might be that you are planning to attach it to. So how can this be answered reasonably?
But if you are making commercial quantities of beer, I suppose you might have a mill big enough for that to be reasonable if you size the pulleys to give the appropriate speed.
Most just use a small variable speed drill motor to turn their mills for homebrew size quanitities. Some of us still just turn the crank by hand.
But if you are making commercial quantities of beer, I suppose you might have a mill big enough for that to be reasonable if you size the pulleys to give the appropriate speed.
Most just use a small variable speed drill motor to turn their mills for homebrew size quanitities. Some of us still just turn the crank by hand.
I use pulleys to reduce motor speed for mine--1" on the motor shaft and 12" on the roller shaft, which brings it to a tad under 150RPM. In hindsight, wish I had bought a gearbox instead. My Monster Mill uses sleeve bearings, not rollers, and I am concerned with wear due to side-loading from the belt tension.
If your mill uses ball or roller bearings, side-loading from pulleys should not be as much of an issue.
BTW, check the motor speed. If it's 3450 RPM, you'll need to gear it down twice as much.
If your mill uses ball or roller bearings, side-loading from pulleys should not be as much of an issue.
BTW, check the motor speed. If it's 3450 RPM, you'll need to gear it down twice as much.
Or a larger, low speed, heavy duty drill, such as this one found at Harbor Freight for $65, or less (on sale, coupons, etc).
Here's an older version I have of a similar drill, max speed 550 rpm, almost permanently mounted on my MM2 milling station:
I have that same drill. How do you have yours mounted to the base plate? I'd considered seeing what thread the handle hole has and bolting it down using that.
The bottom of the handle is the only part of the drill that's clamped down (to the base). You see the red clamp handle.
Since the drill is a beast, I've kept it removable, and is used for other jobs, occasionally.
I always intended to make a better mount/clamp for the handle, but has had no priority.
The hole is less than 1/4 inch in diameter, perhaps 3/16".
I envision a U-brace or pipe strap over the bottom of the handle, around where the clamp is now, with some foam or cork padding underneath and 2 screws should do it.
Do you use the lock on the trigger? I feel like push it in to where the trigger locks is going to fast for my taste.
Absolutely! Milling is done hands free, that was my goal.
While under load (milling that is), I turn the little yellow wheel* until I get the milling speed I want, aiming for around 150-160 rpm on my MM2, going by the sound now mostly. I always start the mill before I fill the hopper. It slows down remarkably, you can hear it "chewing" through the grain.
To get an idea of the speed, I've put a black mark on the chuck, and with a short video, played back slowed down, I can count the # of revolutions over 10-20 seconds.
* Once adjusted to the right speed, I don't move the speed wheel/trigger anymore. After I've used the mill for a different job (rarely anymore), I follow the same procedure.
I guess I could mark that yellow wheel too, it simply limits the maximum depth you can squeeze the trigger down.
