4.5" smooth roller grain mill???

[Alaskan_Wolf]

Hi all,

First, I'm not sure this is the right spot for this, but it seemed to be.

I'm looking to make a grain mill so I can buy my grain in bulk. Due to limited tools/Fabrication options I was looking into smooth rollers. I have access to a chunk of 4.5" OD steel pipe.

My questions are these:

1. would this diameter roller still be too small to be effective with a smooth surface?

2. If yes to #1... what IS the minimum dia. considered viable?

thanks,
Max

 

[augiedoggy]

Hi all,

First, I'm not sure this is the right spot for this, but it seemed to be.

I'm looking to make a grain mill so I can buy my grain in bulk. Due to limited tools/Fabrication options I was looking into smooth rollers. I have access to a chunk of 4.5" OD steel pipe.

My questions are these:

1. would this diameter roller still be too small to be effective with a smooth surface?

2. If yes to #1... what IS the minimum dia. considered viable?

thanks,
Max

I know the smaller 2-2.5" diameter barley crusher rollers stop working well once their points begin to dull on the rollers.. of course thats a big difference from 4" rollers as far as surface angle.

 

[Alaskan_Wolf]

Yeah, I know that knurling on small Dia rollers is necessary, and rollers 6" and up work just fine smooth (as you pointed out, thanks to the reduced angle of entry)

But... from what I've found online, there seems to be an information gap involving rollers in the 3-5 inch category. And I'd rather have an idea of expected performance of 4.5" rollers BEFORE I spend the time making my mill

 

[Nom_de_Plume]

Ask Francis/Frank at mashmaster.com. He has made mills with those sized rollers. He is a wealth of information on mills. He may help you....or maybe not...I can't speak for him. Worth a try.

 

[user 338926]

I hate to resurrect old threads, but saw this while searching for smooth roller mill info. Many years ago I made my mill using 3" od steel tubing which I think is Schedule 80. I did have the ability to knurl it, but I didn't put a diamond knurl on, I used a straight knurl. Meaning, lines go along the length of the tubing. Very fine lines, not like the mills I've seen with the super deep "spikes". I run a gap of .090, to give an idea just how smooth they still are. that mill will run a 22# batch in about 40 seconds using a motor and gearbox I picked up on Ebay, permanently mounted w/lovejoy connector.

I did not use gears to provide synchronized drive to both rollers, so the second roller is an idler. Also knurled straight though. It has never failed to crush grain, but having made the shafts without enough length to add gears on the outside now, I'm contemplating making another mill using 6-3/4" OD steel I have, and I want to add the gears which I can also make, in order to synchronize the two rollers. I see a thread on the forum now where a person with a commercially purchased mill with the knurled rollers is complaining it takes an hour to do 12# of grain because the mill won't mill. Incredible...

 

[IslandLizard]

I run a gap of .090

Although the rollers' large diameter helps, that's a relatively wide gap! Equals 2.286 mm.
How does it crush wheat or rye?

 

[user 338926]

Although the rollers' large diameter helps, that's a relatively wide gap! Equals 2.286 mm.
How does it crush wheat or rye?

I've not done a wheat batch since getting back into brewing 5 or 6 batches ago. But, I did buy a 55# sack of Weyermann Vienna which has large variations in the grain sizes. I was running a .105" gap, and that worked fine for all the grains I'd done. But I had to drop down to .090" to hit all of those. Otherwise, it works splendidly, but I'd just prefer to have less dust (flour) formed.

I ran the gap down in a brew session 2 weeks ago and ran 2 batches at .070 gap. Both sparges stuck. Not a big deal, I just add water, stir, re-lauter and clear it, and start over. Works find the 2nd time. But I'd prefer to not have that again if possible.

 

[user 338926]

To show an example of what I'm talking about with the straight knurl, I just threw a piece of aluminum in the lathe. This is deeper than I did with my steel rollers but the total depth is only a couple thousands of an inch. Nothing like some of these commercial Mills where a piece of grain looks like it would almost fit in the holes.

 

[IslandLizard]

To show an example of what I'm talking about with the straight knurl, I just threw a piece of aluminum in the lathe. This is deeper than I did with my steel rollers but the total depth is only a couple thousands of an inch.

Those "flutes" are very tight!
IIRC, Monster Mill had a fluted roller upgrade, those flutes were also shallow but cut quite wide, ~3/32" and spaced about the same. It looks like they did away with those.

Nothing like some of these commercial Mills where a piece of grain looks like it would almost fit in the holes.

That's why we use 0.034" gaps for barley and 0.022-25" for wheat and rye, and almost touching when milling oat malt.

 

[user 338926]

That's why we use 0.034" gaps for barley and 0.022-25" for wheat and rye, and almost touching when milling oat malt.

One thing to consider is that the gap numbers other folks talk about on these commercially available mills has no correlation with the gap settings on mine. If I set my gap to .022", (and I can) the biggest piece of anything coming out the other side WILL BE smaller than .022". It would be making flour.

I might post a few pics of mine later when I get home.

 

[grampamark]

What’s being overlooked here is the rate of throughput which @4Mesh is talking about. 22 lbs in 40 sec is about 1.8 lbs/sec. At that rate, through a .090 gap, the kernels are crushing each other.

 

[user 338926]

What’s being overlooked here is the rate of throughput which @4Mesh is talking about. 22 lbs in 40 sec is about 1.8 lbs/sec. At that rate, through a .090 gap, the kernels are crushing each other.

Well, that's backward. It's a pound every 1.8 seconds... But, still pretty quick. If I were to make the bigger mill, I bet that'll do a pound a second, if not more.

The motor I bought is a 90V DC approx 1.5hp. Pretty serious motor, and I think it uses a 20:1 gearbox, but I would need to look at that to be sure.

Maybe next brew day I'll take a video of it.

 

[grampamark]

Well, that's backward. It's a pound every 1.8 seconds... But, still pretty quick. If I were to make the bigger mill, I bet that'll do a pound a second, if not more.

The motor I bought is a 90V DC approx 1.5hp. Pretty serious motor, and I think it uses a 20:1 gearbox, but I would need to look at that to be sure.

Maybe next brew day I'll take a video of it.

Yeah. I did the math right but typed it backward. Proofreading matters.

edit-I use a Cereal Killer with a 7lb hopper, powered by an 18v cordless drill. It process about 2-2.5 lbs/min with a .028 gap.

 

[user 338926]

No problemo, btdt.

I am not sure what the hopper capacity is on mine, but it's a lot. I know i did a batch last Sunday that was 23.5#, and I just dump it all in and hit the switch. Guessing here, but I bet it would hold 35# in one go. What won't hold that is my catch bucket which is a 6.5G "Vino Vessel" from either NB or Midwest. I'm going to say at 25# or so you need to start moving the pile or it'll stack up too high and back up into the rollers. It won't dump dead center down the bucket due to weight/balance issues. The motor is offset and very heavy. I bet the entire thing weighs 80# or more.

 

[user 338926]

Rather than cross post in two threads, I'll just stick a link to the one I started to hopefully get input about the mill I want to build. I posted some pictures of my current mill which will give some context to the statements I made above. Years down the road these threads will be separated such that you won't be able to find one from the other.

https://www.homebrewtalk.com/threads/diy-smooth-roller-grain-mill-project-any-tips.726847/