Motor for Grain Mill

[Sawdustguy]

Is a motor with 86 rpm and 21 inch-lbs of torque enough for a grain mill?

 

[ClaudiusB]

Is a motor with 86 rpm and 21 inch-lbs of torque enough for a grain mill?

My motor's torque is at the low limit for any mill.
The mill motor has 16 in-lb of running torque at 94 RPM.
The starting torque is just enough to start with grain between the rollers at my gap setting.
I measured the required starting torque for my mill, just under 30 in-lb.

Mill in action.





Cheers,
ClaudiusB

 

[conpewter]

ClaudiusB what type of mill do you have? Roller lengths/diameter.

 

[Tonedef131]

My motor's torque is at the low limit for any mill.

Hows that thing do with wheat and rye?

 

[ClaudiusB]

ClaudiusB what type of mill do you have? Roller lengths/diameter.

The mill base was made by Automatic, a commercial mill company.
6" long x 1-1/2" DIA rollers, and gap is .035".

Hows that thing do with wheat and rye?

No problem with wheat, never used rye.



Cheers,
ClaudiusB

 

[conpewter]

Thanks! Good to know that you get get by with ~30 inch pounds. I had read 40 was the minimum. I've been searching on ebay for something that will work. I may try to find an ice cream maker at a yard sale. What about windshield wiper motors?

 

[BrewBeemer]

With the 1/3 hp Baldor motor of 1725 rpm with a worn drive output shaft mounted to a 90 degree worm drive gearbox as a single manufactured unit of 60:1 reduction i'm at 565 in/lbs TQ at 28.75 rpm's. Geared up by 3.111 for 89.44 rpm's this drops TQ to 181.6 in/lbs or 30.26 in/lbs per inch of roller length. This turning 2" rollers on a MM3-2.0 mill with 6" long 3 roller mill. This would be the same as a 1 1/2" roller mill turning at 119.25 rpm's if you match the surface speed of the rollers in inches per minute. Fast enough for me without making flour with gearing up to a 1/2" diameter jackshaft with sprockets supported with two pillow bearings and a 28:9 tooth gearing. The other end of the jackshaft direct coupled to the mills 1/2" input shaft drive allowing for no side loading on the drive bushing with a LoveJoy alignment coupling for the mills drive.
I think this will make a nice build project just needing a hopper and a short 6" long chute under the mill for the bucket not wanting to throw grain all over the floor but aimed straight down into 5 gallon bucket.
My plan is to mount the top and bottom of the mill on 1/8" to 1/4" thick aluminum plates to keep the mills end plates in alignment as well the end play in a solid fixed position. Mount this top plate under a table and the lower chute to the bottom plate is in my plans. Build it solid without the mills end plates flexing should allow for a lot longer bushing life besides cleaner running of the bushings by holding tight roller end clearances keeping grain dust and debris at a minimum reaching the bushings.

 

[ClaudiusB]

What about windshield wiper motors?

conpewter never used one.
I don't like the idea having to use a large power supply besides the motor.
Those motors draw over 8 Amps under load.
AC gear motors are more convenient, less current.

I checked with the German brewing community, they use windshield wiper motors for mills, and mash mixers.

BrewBeemer as soon you feel better start building your mill, we all like to see it.


Cheers,
ClaudiusB

 

[Homercidal]

Windshield wiper motors seem like they would be too small for crushing. But I'm willing to try since I can pull bunches of them out of cars for a couple of dollars each...

 

[BrewBeemer]

conpewter never used one.
I don't like the idea having to use a large power supply besides the motor.
Those motors draw over 8 Amps under load.
AC gear motors are more convenient, less current.

I checked with the German brewing community, they use windshield wiper motors for mills, and mash mixers.

BrewBeemer as soon you feel better start building your mill, we all like to see it.


Cheers,
ClaudiusB

I sure as hell wish I could move around and do some work. Even lifting the MM3-2.0 in the box off the floor will hurt me for days again. What are we talking a 25 pound item and it is over my backs limit with me back on Percocets 5 times a day again. I'm trying to get off the addiction of them as i'm hooked at the moment and when I do something stupid like lift or bend i'm delayed for weeks again on the healing. The surgeon does not want to repair what he as fixed again. Was told a wheelchair could be in my future if I don't give the back time to heal up and stop being so stubborn and thick headed. Might be the German in me? Tell me about the frustration i'm going thru besides the pain 24/7, this is why i'm up again at 2 AM in pain and stiff waiting for the Percocet to kick in again. A simple high seat and handlebar stunt bike geared super low, three blocks at 5 mph wiped me out for a week. I thought this would be a short test
on the lower spine. Big mistake. Very limited life at 56 and it sucks as I have plans and ideas besides purchased equipment. Hell i'll be happy to have my mill, motor and parts half layed together on the floor for a picture would be progress for me and this will be with needed lifting help. Perks, no bier either, rather have bier no Perks. No mixing. Thanks Claudius B. for kicking me in the butt as I need this while on the mend.

 

[Sawdustguy]

I hear you BrewBeemer. I am going to turn 55 in July and I am going to need a right knee replacement very soon. I am 1/2 German descent and am stubborn as hell. I can't see having the replacement anytime soon. What ever happened to ageing gracefully?

 

[conpewter]

I know an AC motor would be easier to just attach and plug in, but the wiper motors are smaller and less costly. From my reading online it can be run at 70 RPM with ~160 inch pounds of torque, or you can run them faster by connecting the high terminal to the low terminal, but that might burn out the motor. It would run at around 100RPM wired that way.

Wiper Motor Page

I'd just use a computer power supply to provide the power. That will provide plenty of amperage.

 

[Homercidal]

Still curious about the wiper motors. I'm planning on going down to pick up my Mustang this weekend and might be able to talk the FIL into going to the U-Wrench-It yard. If so, I'll grab a couple and try them out.

But if that don't work, I know where some spare gear motors are sitting around at work. I'll see if they want to part with them for cheap tomorrow...

 

[conpewter]

Sounds great! I'm still working on getting a mill, I'm looking to get a wiper motor as well (as you know Homercidal).

 

[Sawdustguy]

Alright, now you have me intrigued. I have an extra 12 VDC high current power supply I used to power my 2 meter rig with here at home (KB2VVS) that I could use to power the wiper motor. How would I go about attaching it to my Mill? What RPM are the wiper motors? It looks like they will have more than enough torque.

 

[conpewter]

From the website I've been reading Wiper Motor Page

his Saturn wiper motor is 41 RPM on the low, 70 RPM on High and 106 RPM if you connect high to low (not recommended). ~13.5 ft-lb on high (70 RPM)

I'm not sure how to connect it to the mill as I still need to get a motor and look at it.

 

[Homercidal]

Sounds great! I'm still working on getting a mill, I'm looking to get a wiper motor as well (as you know Homercidal).

Yes, and I am keeping you in mind as I pull a few. I'll probably grab 3-4 of them of different types if we go to the salvage yard.

 

[Homercidal]

Alright, now you have me intrigued. I have an extra 12 VDC high current power supply I used to power my 2 meter rig with here at home (KB2VVS) that I could use to power the wiper motor. How would I go about attaching it to my Mill? What RPM are the wiper motors? It looks like they will have more than enough torque.

Too bad my homemade 2M DC supply didn't work out. I ended up pitching it because it was too noisy and underpowered and the project was becoming a lot less interesting when you factor in the fact that a usable retail supply was not very much money.

So I used a car battery for whenever I went on the radio. My friends all moved out of 2M range anyway, and even though I could use the link system that runs down the state, cell phones, teamspeak and email have filled in the needs for my home use. I just never get on anymore, although I have thought about upgrading since they lowered the requirements so much. (KB8VUB)

A car battery might work fine if you have one, or maybe even the charger if you have one.

 

[Homercidal]

From the website I've been reading Wiper Motor Page

his Saturn wiper motor is 41 RPM on the low, 70 RPM on High and 106 RPM if you connect high to low (not recommended). ~13.5 ft-lb on high (70 RPM)

I'm not sure how to connect it to the mill as I still need to get a motor and look at it.

I know some guys that do the electrical controls on our machines, and go to church with the owner of that company, so I could ask one of them how best to wire it up.

As far as connecting, I'm considering using some Lovejoys to mate the motor to the crusher. Or, there is an interesting solid(ish) connector that I saw on some old equipment at work that might be useful. Basically a solid cylinder that fits between the two shafts and connects them. Except, the cylinder has been cut over halfway through in several places in the middle, and in different directions, so that it is somewhat flexible.

But when it fails, it's done for. We go sooo many lovejoys laying around under layers of dust, I'm sure I could snag one, and I don't think they are too expensive to purchase either.

 

[babalu87]

My motor's torque is at the low limit for any mill.
The mill motor has 16 in-lb of running torque at 94 RPM.


Cheers,
ClaudiusB

Yeah, your at the lower limit.

I had a reduction gear motor that was 14 in/lb and it was just short of enough power.

 

[Homercidal]

I finally got around to rigging up my wiper motor. The results were initially encouraging. I held the motor in my hands and connected it via a 9/16 socket, because my homemade crusher has a bolt head on the driveshaft. I crushed about 2 lbs of Pale Malt. It was pretty slow on the fastest wiring the would crush. A faster setting was not strong enough to keep it moving.

The next day I rigged up a brace and mounted the motor to it and ran some more grain through it. I crushed about 8 lbs. However, near the end of that 8 lbs. the already slow crushing was nearly at a dead stop and the motor was getting pretty warm.

The slow crush rate and struggling motor made me conclude that this setup was not feasible. I stripped the internals out of the motor and stripped the windings from the motors output shaft. I connected a high-speed hand-held drill to the shaft and powered the wiper motor with that drill. It was much slower than before, but probably had plenty of torque.

1. My homebuilt crusher likely has larger diameter rollers. I used whatever scraps of round stock were available at work. A purchased crusher might not struggle if it has smaller diameter rollers.

2. I powered my wiper motor from a battery charger. I am not electronically smart enough to know if this makes a great difference in the power or speed of the crusher. I did try it on 50 AMP BOOST and it helped speed it up a bit and keep crushing near the end, but the improvement was not enough to make me want to run it like this all the time.

 

[cruelkix]

I have an old vaccum lying around. Motor works great I was just tired of buying new bags fo rthe thing. I would assume it has a least an 8 amp electric motor that would have plenty of power if I gear it down so the RPM's arent crazy high. anyone think of using a vaccum motor before?

 

[conpewter]

I tried to use a hand mixer but it burned up.

 

[Catt22]

The most cost effective way to go is with a Harbor Freight 1/2" corded drill motor. Not the most elegant solution, but it is low cost and will do the job well without the need for belts and sheaves.

I went with a gear motor, but I got it for almost nothing.

 

[cruelkix]

So I ripped the vaccuum motor out and the thing is prety bad ass. It is a 12 amp motor with some really high RPMs. I think Im am going ot have to wire in a potentiometer as the on off switch just doesnt really seem to be the way to go. I figure if I can get the RPMs down to something respectable I may not have to gear or belt this thing down. I'll keep ya'll updated.

 

[lamarguy]

I recently purchased a brand new bodine 31 in/lb 187 rpm gearmotor off ebay for $40 shipped. I think I got pretty lucky considering those motors cost $300.

 

[pilotdane]

Try looking at Surplus Center. They have all sorts of electric motors, gears, chains, sprockets, motor controllers... Double check their prices if you can. Some items have been a real steal while others are high.

 

[cruelkix]

Dang I didnt realize it would be so expensive to have some sort of variable limit on a vaccuum motor. If you do the math the thing is drawing 1,440 watts (120v @ 12 amps). Everything I can find to limit the output of this thing that is rated to that many watts is like $300. Anyone have a cheap solution to get this thing to run slower?

 

[Catt22]

I'm not sure if this would work with that particular motor or not:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43060

Might be worth looking into though.

 

[cruelkix]

I'm not sure if this would work with that particular motor or not:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43060

Might be worth looking into though.

Nice!! I think that will work very nicely. And if it doesnt I can use it with my router haha. You rock!