Home Built Grain Mill - From Scratch
- Thread starter EZCyclone
- Start date
Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:
Ha ha, Thanks man. Yeah I wish it was really only $27 worth of materials total. I have piles of automation stuff laying around here, so often I already have lots of the parts for fun things like this. lol
I should probably PM you this... but... I've been looking into doing what you just did for certain reasons. I've noticed that there is a deficiency with current grain mill design for home brewers which you've certainly rectified whether intentionally or not. So, I just want to ask you, what would you charge for your knurled 2 7/8" rollers to make a set? PM me the price. I have an idea that I would like to come to fruition.
Csuho
Well-Known Member
Well I notched the drive roller and got some o rings last night I need to try that option to see if it works. I hate to try and get the rollers reknurled again. As for the gear option anyone have thoughts and links. The rollers are 1.5" center to center on the rollers. I couldn't find gears for less than $10-$12 each in a quick search. I hate to spend alot and then it not work and need something else where are I am getting to the point of just buying 1. Thanks for the help so far guys.
Csuho
Well-Known Member
tried the o-ring option and it worked for about 3.5# of malt with a cordless 18v ryobi but it struggled. Then switched to the d-handle drill from harbor freight. That had no problem running it but it shredded the o-ring. Now I am on the hunt for gears.
Hmm, what about chain drive? No seriously, they make tiny chain and sprockets, would work perfect, and even leave you with adjustibility.
My LHBS sells mills that have the Oring in them just like I described, but no idea if they last very long.
I'm working in the shop for a few more hours, I'll look for some parts for you when I get home.
My LHBS sells mills that have the Oring in them just like I described, but no idea if they last very long.
I'm working in the shop for a few more hours, I'll look for some parts for you when I get home.
Csuho
Well-Known Member
I found sone gears that would probably work for $10 for both gears, but they are plastic I am not positive they will hold up buy I think they will. Steel gears are around $15+ each. Coming from an rc car background those cars take abuse but kit sure the abuse a mill would give out.
I need to post a link to the plastic gears but I am on my phone. I will tomorrow.
I need to post a link to the plastic gears but I am on my phone. I will tomorrow.
Nice piece of engineering.
Knurl what pitch/depth
Knurl what pitch/depth
northcal
Well-Known Member
Awesome mill!
I'll get a pic of my ghetto one on here so you can see how large you're livin'!
:rockin:
I'll get a pic of my ghetto one on here so you can see how large you're livin'!
:rockin:
Nice piece of engineering.
I can't give away all my secrets now can I?
lol. It's the trick behind my grind. Come to my shop and I'll show ya. 
Umm, I guess I would probably cut you out a set of gears on the CNC if you were interested for say $20 + shipping?
Csuho
Well-Known Member
Might have to take you up on that EZCyclone.
I will do some more digging and see what I can come up with though.
http://www.amazon.com/dp/B00975O3VQ/?tag=skimlinks_replacement-20
Those seem that they would work if I am reading the dimensions right. My center points are 1.5" so if I am thinking right 2-1.5" gears would work with a pitch circle diameter and then and OD of 1.75" would give enough slop in there for adjustment. I hope I am thinking of this right if not someone please correct me.
I will do some more digging and see what I can come up with though.
http://www.amazon.com/dp/B00975O3VQ/?tag=skimlinks_replacement-20
Those seem that they would work if I am reading the dimensions right. My center points are 1.5" so if I am thinking right 2-1.5" gears would work with a pitch circle diameter and then and OD of 1.75" would give enough slop in there for adjustment. I hope I am thinking of this right if not someone please correct me.
Last edited by a moderator:
Those are nice gears, they should work fine. They wont work forever, and not long if you mill a lot with it, but should be fine for a once a week brewer for a while. Disclaimer, I only looked at the material, not the numbers you threw out. It's to early in the morning for numbers.
gee long trip
But a seriously fun time! Lol. My fav professor is from Tasmania, he would get a real kick out of it.
northcal
Well-Known Member
You are more skilled than me!
here is my ghetto mill that my brother gave me for a Christmas present.
I need to paint the wood and steel frame as they collect dust that grows mold, also the rollers could use some maintenance as I need to supplement the 1/3 hp motor with a drill on the other roller to keep it moving. It is adjustable for the gap, but that's too much a PITA to mess with so I just run it through twice.
Not saying I don't enjoy the mill, but just that I could maintain it better (bro).
here is my ghetto mill that my brother gave me for a Christmas present.
I need to paint the wood and steel frame as they collect dust that grows mold, also the rollers could use some maintenance as I need to supplement the 1/3 hp motor with a drill on the other roller to keep it moving. It is adjustable for the gap, but that's too much a PITA to mess with so I just run it through twice.
Not saying I don't enjoy the mill, but just that I could maintain it better (bro).
northcal
Well-Known Member
This could be part of the problem. Second most important factor in your mills performance is SFM, surface feet per minute.
Look and see what speed the motor is, my guess is 1725 or 3450RPM, lets hope it's 1725. Then measure both pulleys and report back. Keep track of which one is on the motor. Then we can see if you are running to fast.
Look and see what speed the motor is, my guess is 1725 or 3450RPM, lets hope it's 1725. Then measure both pulleys and report back. Keep track of which one is on the motor. Then we can see if you are running to fast.
northcal
Well-Known Member
OK, EZ, the motor is actually 1/2 HP and has 1050 rpms. Any insight appreciated!
Thanks,
The roller pulley is ~6.5"
The motor one is ~3"
The rollers are maybe 1.5" round stock?
Thanks,
The roller pulley is ~6.5"
The motor one is ~3"
The rollers are maybe 1.5" round stock?
3" drive pulley and 6.5" main pulley at 1050RPM
That means:
6.5"/3" = 2.17:1
1050RPM /2.17 = 484RPM
1.5" Rollers = 1.5" X Pi = 4.71" per Rev.
4.71" x 484RPM = 2,281" per minute speed
2,281" / 60secs = 38" per second
38" speed / 12inchs = 3.17 FEET PER SECOND.
Let's just say that's....... a bit high.
Let's try and get it closer to 2.3-2.4 fps ok?
So we want to try and make the main shaft run at 360RPM
about 25% slower than before.
So you have three options,
1. Upgrade main pulley
2. Upgrade motor pulley
3. Upgrade both pulleys
1. If changing only the main pulley, you will need a 9" pulley on the mill. This with your 3" drive pulley gives you a reduction of right at 3:1 so 1050RPM / 3 = 350RPM.
2. If changing the drive pulley, you will need a 2.25" drive (motor) pulley to run your 6.5" main pulley at 2.88:1. So 1050RPM / 2.88 = 364.5RPM
3. Now, if you want to start from scratch, all you need to do is pick two pullesy that have a ratio as close to 2.91:1 as possible. Yes this can be daunting, but don't let a few points either way discract you, as you see above we wavered by a RPM or 15, this is no big deal. Unless you machine your own pulleys to excact dementions you will never get the 2.91:1 ratio. 3-1 is close enough.
Admittedly that motor is probably a little shy for what we need here, but even if you put a new motor on it, the upgrades we are talking now will sure beef the thing up. Now that said, if you are thinking of a future motor upgrade, remember that it will likely be a different RPM then this one. So we would need to change ratios again. Just keep that in mind. But never dump gain in without the motor running. I promise that one does not have the torque to start a hopper full of grain. (at correct adjustment) If you don't mind running the grain twice, then leave your gap alone. It would drive me nuts, but in crazy. It will however, if you leave it where it is, help with the motor torque issue.
I think that's all I have for now, you may find that once you do the upgrades you still might not have the second roller spinning all the time. I found this in my research prototypes, but a bump with a stick would always get it going. My new mill no longer needs this though.
Hope this helps, I'm always here if you need more answers.
That means:
6.5"/3" = 2.17:1
1050RPM /2.17 = 484RPM
1.5" Rollers = 1.5" X Pi = 4.71" per Rev.
4.71" x 484RPM = 2,281" per minute speed
2,281" / 60secs = 38" per second
38" speed / 12inchs = 3.17 FEET PER SECOND.
Let's just say that's....... a bit high.
Let's try and get it closer to 2.3-2.4 fps ok?
So we want to try and make the main shaft run at 360RPM
about 25% slower than before.
So you have three options,
1. Upgrade main pulley
2. Upgrade motor pulley
3. Upgrade both pulleys
1. If changing only the main pulley, you will need a 9" pulley on the mill. This with your 3" drive pulley gives you a reduction of right at 3:1 so 1050RPM / 3 = 350RPM.
2. If changing the drive pulley, you will need a 2.25" drive (motor) pulley to run your 6.5" main pulley at 2.88:1. So 1050RPM / 2.88 = 364.5RPM
3. Now, if you want to start from scratch, all you need to do is pick two pullesy that have a ratio as close to 2.91:1 as possible. Yes this can be daunting, but don't let a few points either way discract you, as you see above we wavered by a RPM or 15, this is no big deal. Unless you machine your own pulleys to excact dementions you will never get the 2.91:1 ratio. 3-1 is close enough.
Admittedly that motor is probably a little shy for what we need here, but even if you put a new motor on it, the upgrades we are talking now will sure beef the thing up. Now that said, if you are thinking of a future motor upgrade, remember that it will likely be a different RPM then this one. So we would need to change ratios again. Just keep that in mind. But never dump gain in without the motor running. I promise that one does not have the torque to start a hopper full of grain. (at correct adjustment) If you don't mind running the grain twice, then leave your gap alone. It would drive me nuts, but in crazy. It will however, if you leave it where it is, help with the motor torque issue.
I think that's all I have for now, you may find that once you do the upgrades you still might not have the second roller spinning all the time. I found this in my research prototypes, but a bump with a stick would always get it going. My new mill no longer needs this though.
Hope this helps, I'm always here if you need more answers.
northcal
Well-Known Member
Thanks for the info, EZ!
I think my rollers are quite a bit less than 12", if that matters though?
More tomorrow, I'm heading out to grab another homebrew!
Thanks,
I think my rollers are quite a bit less than 12", if that matters though?
More tomorrow, I'm heading out to grab another homebrew!
Thanks,
That certainly helps with the torque issue. Come to think of it, you may not have enough surface area to achieve a continues feed of grain. But if that is the case, we still have your gap to try, and then we will just find parts to geear drive the thing. :rockin:
northcal
Well-Known Member
Still waiting for that more info,
Will get back to you with numbers tomorrow.
Thanks again!
Will get back to you with numbers tomorrow.
Thanks again!
Ha ha, no sweat. Just want to get you back in the game.
