What RPM do you run your grain mill at?

[ahansen]

Anyone want to chime in re why I would use pulleys vs. a speed controller to dial-in my RPM's? Is it a matter of just having the motor running wide out and then gearing to the ideal speed or is there more to it? I mean, I'm looking at a 1750 RPM motor where a speed controller will cost roughly $25 vs. a set of pulleys and belts that will cost roughly twice that (unless I'm losing my mind).

 

[johns]

I have not done anything like this befoer, but I plan to do so in the near future. My thinking is that if you have a speed controler it would be for a motor that has 200-300 rpm which seems to be a bit much depending on the mill being used. If a pully system is used the low rpms are constant. Maybe its just a toy to ramp up or down the rpm.

As for me I am looking for something that has under 200 rpms and high torqe (over 50 inch pounds). I dont really care about a speed controller. Also a love joy coupler is a nice option to have simply to reduce bearing wear on the mill.

I recently bought a high torque drill and for now it seems to work, although I really need 2 hands to control it. One for the grain mill (it seems to want to tip over at low rpms) and the other for the drill. A nice motor hook up is a nice way to go.

 

[shushikiary]

Torque. Remember that when you put a smaller pulley on the motor and a larger one on the mill it multiplies your torque.

So if you have a 50 inch lbs motor that runs at 300 RPM and you gear it down so the mill is running at 100 RPM you just trippled the torque the mill sees.

I've found that for my mill direct drive when doing malt conditioning required me to get a 115 inch lbs motor.

 

[Hang Glider]

wow -necropost!

I'm not at home to check torque specs, but my gear motor runs a very slow 62 RPM - and it would crush gravel. I load up the hopper and walk away.

 

[MX1]

wow -necropost!

I'm not at home to check torque specs, but my gear motor runs a very slow 62 RPM - and it would crush gravel. I load up the hopper and walk away.

what motor are you using?

Tim

 

[Hang Glider]

its a Bodine gearmotor, 130VDC from eBay - had to build a converter to AC, though.

looks like this one but I paid less than a tenth of that list price.

130VDC converts to 90VAC - so there was a bit of studying...

 

[johns]

its a Bodine gearmotor, 90VDC from eBay - had to build a converter to AC, though.

RPM? Torque?

 

[beaksnbeer]

This is my motor 120 rpm at 150 inch lbs

 

[johns]

its a monster, but it cost a pretty penny

 

[StMarcos]

This is mine. 90rpm. Works great.

 

[beaksnbeer]

its a monster, but it cost a pretty penny

Nope, $25 on e-bay and $40 for the control. If your not worried about speed I have a Dayton model 4Z130B 1/8HP 90Volt DC 22rpm at 280 in lbs of torque leftover that I was going to use to stir the mash. $30+ shipping

 

[aberahaileyesus]

Does the desired grain size and rpm of the motor has a relation.

 

[fun4stuff]

I just bought a cereal killer mill. Was going to use my drill. What’s best way of figuring out RPMs?

 

[eimar]

I don't know because my wife is milling the grain manually

 

[day_trippr]

I use an ancient GE fixed speed gearmotor that runs at 180rpm.
Short of using a tachometer I'm not sure how one would measure RPMs on a variable drill...

Cheers!

 

[toms_Jeep]

I run mine at 175rpm with a servo motor and controller. I am about to change it very easily in 5-10 rpm increments.

 

[toms_Jeep]

Here is a picture of my setup during the build.

 

[Hang Glider]

old DC gearmotor makes for a speedy 62 rpm for mine - but y'know, I dump the grain in and go wash something...no big deal

 

[Brewbuzzard]

1. K

   I just was gifted a 5 HP 3450 RPM motor. I've got a 2" Drive Pulley connected to a 8" Driven pully on a mandrel, which I'll attach to the barley crusher via coupling. The resulting rpm is 862.5 or a .25 reduction

How fast is too fast? I was hoping to keep with the 8", but if I need to, I'll start looking for a 10 or 12"

I set mine at 200 rpm. Too fast and you shred the husks and create a lot of flour. Also, there are a couple old threads on homebrewtalk that cover this topic (mill RPM ????? and another about where to source pulleys for grain Mills). However, the motor you have has too many RPMs. Unfortunately you need a different motor.

 

[Ruint]

You need to do the math for the size pulley your going to need. My speed is about 172 rpm. You will be wanting to get the smallest motor pulley you can. If I recall correctly, I had a 3/4 od going to the pulley which I think was 14, 15, or 16 inch. Can't remember exactly. I do know it was still spinning faster than optimal ...until I put a 10 to 1 reducing gear box as my mill drive. If you have a 3425 motor spin, you will have a monstrous pulley driving your crush roller.


Laughing at myself for answering a 9 yr old post. Don't know how I missed that....actually I do... 11.5 abv quad and distractions from the mrs.

 

[Brewbuzzard]

I affixed an old belt driven variable speed drill press to run my malt mill. I found running 500 - 600 rpm sufficient. I have run it up to 1700rpm and the quality of the crush was the same the only fear I have is prematurely ruining the bronze bushings.

500-600 RPM is very high for milling barley and if you see no difference between that speed and 1700 RPM maybe the speed you are using is giving you an inferior crush.

 

[day_trippr]

Wow. Gotta believe there's a hella lot of dust created at those speeds...

 

[bracconiere]

i don't even know what rpm i run mine at, just have a variable speed lock drill....i set it at what ever seems 'right'.....i think it's 600-700 full speed, and i run it at half that....

 

[swiftsail]

Put a magnet on you shaft and get a free android app magnetic counter to measure RPM

 

[day_trippr]

There are also strobe light based phone apps that can help determine RPMs...

Cheers!