Grain Mill attempt.... need some idea help

Background: I just brewed my last Extract batch Sunday night. I currently have around 400 bottles conditioning, and 2 5 gal batches in primaries. SO, i'm ready to start putting together equipment for all grain (i'm on a tight budget, so it will be a few months of spending money).

I've got a cooler ready to be my MLT, and am looking for a keg to convert to keggle.

I wanna buy grain in un-milled in bulk, and i'll need a crusher so i've been keeping my eyes open. Today at work i found 2 14in long x 2in diameter steel rollers on ball bearing 7/16 shafts. I cleaned them and hand scored them at a 45* angle to help them with some 36grit pads for an angle grinder, thinking this will help them "bite" or grab the grain.

My plan is to make a feeding bin with scrap 22ga galvinized sheet steel we have at work. and fabricate a base with adjustable gap similar to the drive chain adjustment on old honda motorcycles. a bolt on each side you tighten to shorten/lengthen the gap.

To crank the grain i'm gonna start with a 7/16 end wrench welded to some flat stock with a crank handle on the end. Eventually i'd like to do an electric drive that will directly turn both rollers, but that's for another day.

Here's where i need help.

I don't know what a grain crusher/mill needs to look like. and i don't know what the gaps need to be.

I'd love some pics (esp of DIY mills) to help me wrap my head around what i need to get put together. And any info you think may be helpful. I'm feel like i'm driving a little blind here.

Thanks!

Here's 2 diy grainmill designs from our friends down under;

http://oz.craftbrewer.org/Library/Gear/GSanders/Gsmill.shtml

http://oz.craftbrewer.org/Library/Gear/GScarman/Mill/index.shtml

Revvy said:

Here's 2 diy grainmill designs from our friends down under;

http://oz.craftbrewer.org/Library/Gear/GSanders/Gsmill.shtml

http://oz.craftbrewer.org/Library/Gear/GScarman/Mill/index.shtml

Click to expand...

Boy, I don't know how much grain those Aussies are planning on milling (well, they ARE Aussies.....), but those mills sure look like overkill for my 5-gallon batches.....I'm strictly of the "Ugly Junk" Corona mill persuasion. The advantage here is BA_from_GA obviously has the skills and access to the materials to DIY up right.....and I'm kind of envious of that.

Revvy, those pics were incredibly helpful, particularly in how to make a hopper that will feed into the rollers with out issues. Thanks!

Regarding my skills for DIY, i don't know if i necessarily have the skills. I do happen to work in a shop where we accumulate lots of junk, which is fortunate. Beyond that i'm just really really REALLY cheap and will do anything to save a buck or two. I figure if i can find some scraps laying around and use it instead of throwing it away, worst case is i fail but maybe learn something. and i can always go buy a grain mill if this fails miserably.

I finished the rest of my AG setup (MLT, Keggle, etc), just need to get the grain mill assembled and i'll be ready to go.

here's a pic of the mounted rollers



here they are with the top laying on them



and here's the whole setup pieced together on a 5 gal bucket.



What i need to figure out is the gap i should have between rollers. I was initially going to do and adjustable gap, but my plan wasn't as feasible as i'd hoped. Do i need a specific gap? I can get it pretty precise... down to the thousandths of an inch. Just not sure what it needs to be to get the best end product/efficiency/ etc.

Any suggestions?

I'll also build a sheet metal hopper that will screw into the top piece, and a a metal piece to overlap the bottom piece of wood with a hole cut in it and flaps folded down to direct the milled grain all into the bucket.

That will depend on if you condition your malt. I saw .026 if you do.

Without knurling on those rollers it wont pull the grain through.

Pat

How are you going to drive the rollers?

I second the knurling as with my diy mill the knurling wasn't coarse enough and it wouldn't pull grain thru (it was orginally like the knurl on a ratchet)

i would try and get ur gap at 0.040 a credit card be4 the numbers is 0.040 i believe.

ok.

the rollers are roughed up a fair amount. I scuffed them with an angle grinder. They just look shiny in the pics. Any method of knowing if they're rough enough to grab the grain other than trial and error?

To power it i'm going to use a Drill. the shaft of the rollers is 7/16 hex so i can just put a socket on it and put in the drill.

Those rollers won't work. You will not get enough knurling on them, as they are thin walled. You will also probably end up bending them. I use the rollers at work, and they are easily bent.

I say press on with the build if it doesn't work your not out much. This thread https://www.homebrewtalk.com/f11/using-pasta-maker-mill-grain-75784/index39.html
discusses at great length roughing up rollers. I used the drill bit in reverse trick. I've milled about 15 batches so far with it.

If all else fails get your girly side on and go to Michael's or JoAnn's with your 50% off coupon and do a pasta maker grain mill for around $15. Sounds like you have the capacity to make a hopper for it.

Edit:
Could you take a threaded dowel rod through on of your mountung boards, out slots in the top board the dowels would slide in. The use wing nuts and washers to tighten once the gap was set. I would think it might be a pain getting the gap consitent across the roller though.

Yeah, for the grand total of $jack-squat i've got invested in this sofar, i'm gonna keep going. Greeneyed may be proven right on the rollers, but they are some pretty heavy steel (like 6lbs each), and we buy them to use to roll car wheels on every day, so i'm gonna give them a shot.

bigjoe - i like that idea for the dowels, i was thinking something similar with threaded rod and lock nuts, but had the same concern about consistency. what if i did threaded rod through the side pieces below the rollers, and marked the gap length on the top of the base, so that each side could be adjusted and locked into place horizontally instead of vertically, and then had some vertical bolts that could be tightened down to ensure it remained stationary? hmmm.. Think I'll get 1# of grain and make sure the rollers are gonna work before i go that in depth.


I'm thinking i may do very light opposing grooves (clockwise on one, counter clockwise on the other) with an angel grinder and cutting blade to help give the rollers some more bite.

Thanks all... hopefully will have more to update tonight

I'm sure you can find some metal shop around that will knurl those rollers for you. Crankandstein has a shop in ATL and would probably be willing to do it for a fee.

Good luck, but I still have concern with the rollers. They may weigh alot, but most of the weight is in the center hex rod, and the spring inside. The outer portion is thin metal, and is crimped onto the end caps. Where we see failure is either at this crimp, or the bearing to hex rod points. With just downward force, we have little issues. But in place where we use them for a flattener, we replace them 10X more often.

But again good luck, and at least they are free.

ok, spent a while knurling (clamped roller to bench and half stabbed, half pounded at it with an angle grinder). about 10 min each and here's what i've got.





sorry they aren't that great, camera doesn't do well close up. The gouges appear smooth in the pics, but aren't when under closer view. How does that look?

that might work, only way of telling is to do some tests.

If you can get some end rolls from a conveyor it would probably be easier to make a mill. They're much larger diameter (6 inches or more) and much thicker, but you'll need to find a piece of scrapped conveyor.

gturner6ppc said:

If you can get some end rolls from a conveyor it would probably be easier to make a mill. They're much larger diameter (6 inches or more) and much thicker, but you'll need to find a piece of scrapped conveyor.

Click to expand...

Agreed. I have a couple of 2" X 8" rollers from a "v" conveyor that I am going to have knurled.

ok, got everything assembled finally today. Unfortunately i didn't have any unmilled grain, or time to get to LHBS before they closed. I did however have some grain that i had previously crushed with a rolling pin, just to see how the rollers would function (since one is driven by the drill, and the other is free on ball bearings) It absolutely pulverized the grain, fed very well at both high and low rates of speed with the pressure of the feed turning the free-floating roller. So i'm going to build the hopper tomorrow at work and swing by and get a pound or 2 of un-milled grain to test it out fully.

side


top


bottom

ok, all done, did my first crush and did a mini-mash with it. 1 lb 2-row 1 gal total volume ended w/ an OG of 1.028. I think that puts me at about 75% efficienct, but i'm not really sure.

here are the pics anyway. Last 2 are of the milled grain.

Maybe I missed this skimming this thread. But how are you turning these rollers?

each roller has a 7/16 center shaft. i use a deep well 7/16 socket in a drill on low speed w/ high torque settings to turn them. It's just not in the pics.

eventually, once i havee the cursh worked how i want it, i plan on making a hand powered crank arm as well.

75% efficincy is correct. The crush looks nice. How long did the 1lb take to crush. Were you able to figure out a way to adjust.

1 lb took between 1 min and 45 seconds to crush at the lowest speed i could run my drill at (which was barely a crawl).

As per adjusting, i went ahead and fix-mounted the rollers to plywood to make sure they were going to provide an adequate crush. Since they seem to be working well enough, i'm going to work on mounting some threaded rod on one the rollers which will slide through grooves on the top and bottom "decks" of the mill apparatus, that way i can slide them and hopefully be able to just tighten the bolts to hold them in place.

I'll probably also skin the wood with metal at that point to provide a surface i could mark with more precision.

I have my doubts about the long term durability here but I think you ought to modify the hopper so it's only dropping a 3" wide ribbon of grain in. Trying to mill along the whole length is going to force the rollers apart pretty hard. It looks like some kernels are getting crushed well, but potentially opening the gap up in the process, letting another 10 through unscathed.

This is closer to what you want, no whole kernels

alrighty. Closed in the gap some more, changed to hand cranking rather than the drill to crush a little slower and not just "shoot" kernels through. also closed the feed width down to about 3.5 inches.

Yesterday i did my first AG batch, crushed just under 10 lbs of grain in about 20 minutes. here's what i ended up with. I also conditioned my malt for this grind.




i ended up with an efficiency just over 65%, but i think that's partly cause i didn't pre-heat my cooler MLT and my mash temp dropped down to ~142 by the end of the mash. (from a strike temp of ~160)

The majority of the husks that were intact were split open rather well i thought.