my new grain mill

[martin w]

heres a few pics of a grain mill i've been working on over the last few weeks,its a 3 roller mill,the rollers are 250mm wide by 112mm diameter,it runs at about 120 rpm, i tested it with about half a kilo of old grain and it was through in less than 5 seconds! the rollers are steel tube filled with concrete on a 20mm axle, my method of centreing the axle was a bit flawed and they weren't all true so i got them trued at a local engineers shop,the pillar blocks and bearings cost just over a hundred off trade me,the stonemason at work retired his concrete mixer just before xmas so i rescued the motor and pulley wheels,all up it cost me less than $200.i'll probably make a better looking hopper at some point as this was the only material i had handy and its a bit of a mess.

 

[JoKing]

Shit hot mate - your mill looks fantastic. Have you noticed any slippage due to having less grip on your rollers - or does the large diameter of the rollers take care of this?

 

Thanks for posting - I'm very pleased to see this.

 

Cheers.

[martin w]

i had to give a wee bit of texture to the rollers with a file but once they grip the friction from the grain just keeps everything spinning,the brewer at the local brewpub reckons closer to 200mm diameter is better for smooth rollers,i'd imagine your getting into some fairly serious drive/power requirements when you start getting into those sizes though!

[Reviled]

lol, jeezuz thats a serious mill!! haha, nice stuff bro!

[Andrew]

Some great work gone into that, Sorry to pee on the party but whats the purpose of the third roller? If the top two are going round the 3rd roller on the bottom will be going in the opposite direction of one of the top rollers.

Great job though, I love to see what other homebrewers come up with in the "Pursuit of Hoppiness". I,ve been reading the Zymurgy magazine (American homebrewers association magazine) and they have a gadgets addition every so often, this would make it in there no sweat!

[Reviled]

"whats the purpose of the third roller?"

 

Monster mill make a version with a third roller and apparantly it will catch and crush anything that gets missed by the first pass... On top of that, it looks cool ;o) haha

[Chris Banks]

Nice work chap!

IMO bigger rollers are the way to go the more gradual pinch angle between the rollers grabs the grain better with no knurling required which is in turn is more gentle on the husks.

Im sure the commercial three or more roller mills have the bottom roller gaps tighter than the top ie 1.5mm top and 1.0mm bottom so the grain gets crushed in two stages. Is that what you were aiming for Martin?

[martin w]

yep,the first gap bigger than the second and the second is adjustable,i couldn't tell you the exact measurements as i don't have a feeler gauge.

[jt]

i'll probably make a better looking hopper

 

Looks fine to me - how much does it hold ?

[martin w]

Looks fine to me - how much does it hold ?

i reckon the hopper would probably hold about 10kgs

 

with smooth rollers it doesn't grab very easily so added a wee bit of texture but once the second roller starts to turn the friction keeps everything moving, if i were to redo i would probably go a bigger diameter but narrower width so texture is not necessary

 

the direction of the second and third rollers are both governed by the direction of the driven roller so the third roller always turns the same way as the second.

 

i'll probably brew next weekend and i'll film the crush if i remember!

[denimglen]

Epic, I wish I had space to motorise my mill.  I'm pretty sure the Supershit Auto hammer drill is on it's last legs :-(

 

 "whats the purpose of the third roller?"

 

There's also mean as commercial mills with like 6000 rollers and sieves and shit that will turn the inside to dust and leave the hull intact.  Saw a diagram once, looked awesome as.

 

"IMO bigger rollers are the way to go the more gradual pinch angle between the rollers grabs the grain better with no knurling required which is in turn is more gentle on the husks."

 

Indeed.  I condition my malt so I've tightened my gap way smaller, sometimes I have a bitch of a time getting it started with the small rollers, especially if I put dry malt in there.