Motorized Grain Mill

[Run4BeerCO]

I just bought the Malt Muncher 3 and was planning to just use my drill, but then yesterday I was tossing out an old Rigid table saw and salvaged the motor before I did. I was doing some research about using a salvaged motor, but I'm stuck on what pulleys/sheaves I'll need etc to bring this whole thing together. Can anyone help me?

 

[bracconiere]

i'm sure someone else can help, but you'd have to give the RPM rating. i think there's online calculators for torqueing them down.

 

[Run4BeerCO]

MM3 recommends 200rpm. I can't find anything on the motor. It has no info on it. I've found some motors online that look to be a replacement part but even they don't have any information either I'm going to look at my Habitat ReStore tomorrow and see what motors they have available just out of curiosity.

It seems like the sizing of the two sheaves would be a simple ratio based on the rpm ratios, right? Bore size would be the shaft size? In the case of the Malt Muncher its 12mm. My experience in buying industrial type parts is that there is always a thousand different options for very specific requirements.

 

[bracconiere]

honestly, i just eyeball my drill RPM, works fine. so just get a big pulley for the mill, and a little one for the motor. something like 2" for the motor, and 12-14" for the mill? i'd guess your motor is around 3,000 RPM.

here something like a calc i was thinking of, says you'd get 496 rpm with 2"x14" pulleys...

https://www.blocklayer.com/pulley-belteng.aspx

 

[day_trippr]

Most table saws/radial arm saw motors have an unloaded speed of ~3450 rpm.
There are exceptions - some Ridgid models have unloaded speeds up to 5K.
Either way, that's gonna be tough to manage for a mill speed around 180rpm.
Most folks running pulleys are starting with motors spinning at ~1700 rpm and that's a ~10:1 reduction...

Cheers!

 

[bracconiere]

Either way, that's gonna be tough to manage for a mill speed around 180rpm.

i run my drill around 400-500 rpm, (i think?) would there be a problem with torque with the 2"x14"? seized mill?

 

[day_trippr]

Woof. At that roller speed you must be shaving kernels and making a lot of powder. But you're doing BIAB, right?

I have had mills bog down but have yet to experience the horror show of a rock literally stopping the mill dead. But my gear motor torque tops out at 44 inch-pounds. I would not want to contemplate what would happen with a 20:1 reduction belt drive using what might be a 3~4 hp motor if that happened.

Cheers! (Yikes! I just did contemplate it. Damn! Not a pretty sight )

 

[bracconiere]

But you're doing BIAB, right?

no, bazooka fly...i mill at .028" too, no stuck sparges.

 

[Run4BeerCO]

Any recommendations where to buy parts online?

Also recommendations on motors if I'm looking in the salvage piles? I don't have many options locally to buy new equipment but our second hand stores are usually well stocked.

 

[day_trippr]

I got lucky with the gear motor I picked up from surpluscenter.com waaay long ago. They don't have anything that would work right now, but that's the type of site I would look towards. If there's a Google function for "sites like <this.one>" I'd give that a try.

New gear motors for driving mills are crazy costly. I paid $89 for my quite used motor (including a clearly padded/profitable shipping charge) and who knows what it originally was used for. Otoh, one could easily spend 3-4 times that it seems these days for a legit mill motor...

Cheers!

 

[IslandLizard]

Since you found the motor, it now feels like it's looking for a purpose, instead of the other way around. I had an old 1 HP pool pump I couldn't find a decent use for.

How often do you brew and how big are the batches?

I use a $50, Harbor Freight, Low Speed Heavy Duty drill (older model) to drive my MM2. Easy peasy for 5 gallon batches, even 2, back to back.
Sure, you can get fancier.

 

[Run4BeerCO]

Ill be doing mostly 5 gallon batches. 10gallon batches sometimes.

Any way to figure out what my current motor's rpm is? I could try counting as it spins??

Assuming it's 3000rpms I would have to have a 15" pulley on the mill and a 1" on the motor? Is there a recommended type of pulley/sheave? Recommended site to buy?

 

[Golddiggie]

I believe you could setup a shaft between the motor and mill to have a third pulley in the mix. Step from the motor to a pulley on that shaft, then from the shaft to the crusher. The link provided before has provisions for doing this type of setup. It will involve more setup and hardware, but you could get closer to your target RPM without having a huge pulley to deal with.

This is why I went ahead and just ordered a gear reduction head motor for my mill. I got it form my mill's maker, not a third party. You could look for one from places like Grainger, MSC Direct or McMaster. IIRC, they are NOT cheap.

 

[IslandLizard]

Any way to figure out what my current motor's rpm is? I could try counting as it spins??

Isn't there a specs plate on it somewhere? Have you tried googling that saw model it came from?

You can't count 3000rpm by looking at it, that's 60rps.
I can barely count my drill chuck's 152 rpm (~2.5 rps) or thereabout, when under milling load.

Do cell phones have a tachometer function/app?

 

[day_trippr]

A quick check shows there are indeed a variety of apps for 'Droids and iFruit that purport to measure rpms...

Cheers!

 

[bracconiere]

I could try counting as it spins??

at ~3000 RPM's you'd not only have to be listening to nine inch nails, you'd have to be doing them! lol, but the pulleys i've seen at my local ACE store?

 

[Golddiggie]

Check Tractor Supply too... If you've got one in your area.

 

[HopSing]

You can try a speed controller but to get it from 3000 rpm to <200 RPM is a big task, but a controller and pulleys might get you there.

https://www.amazon.com/VIVOSUN-Variable-Adjuster-Inline-Controller/dp/B015SLCJ2W/
I got a low-speed drill (sometimes called a 'Mud Mixing drill') that has tons of torque for a 3 roller mill. The one I got can adjust the speed using the dial on the trigger. The trigger also has a lock.

~HopSing.

 

[Run4BeerCO]

For the record... Counting the RPMs was a joke...

The table saw was a salvage in and of itself. I didn't know the model. I was shocked after salvaging the motor that it didn't have a spec plate. I have found what appears to be the exact motor on several sites, still with no actual specs. Blows my mind. Some of my googling shows potential 4700rpm but when I dig deeper the number disappears.

https://www.partswarehouse.com/Ryobi-Assembly-Motor-RY-089037011709-p/ry-089037011709.htm
I'll look at the ReStore today for a slower motor, if not I'll stick with the drill.

 

[Golddiggie]

IMO, a speed controller won't do what you really want for a barley mill. It will reduce the RPM but not increase the torque. Most often you need more torque to either start it, or keep it going. Using a gear reduction head, or pulleys, will give you lower speed and higher torque.

IIRC, a DC motor could give you the torque you need, due to how they work. But I wouldn't use an AC motor in that application. Can you get it to work? Maybe. Personally, I don't see the point to dicking around like that. Hell, I'd use a drill (again) if it came down to that since cordless drills use DC motors and can often offer lower RPM ranges. For reference, I was using my 18v DeWalt hammer drill for years in the lowest (of three) speed ranges finger fiddling it to get the speeds in the needed range.
I got tired of having to hold on for dear life when I started the drill (when attached to the mill) due to the level of torque applied/needed. That's why I went ahead and got the motor I did before we brewed our first batch this year. Gear reduction heads also mean you can have the motor shaft directly in line with the malt mill shaft. Thus preventing any side load force and prevent wearing out the bushings/bearings in your mill prematurely.

 

[electricsailor]

I suspect you will have a hard time getting the RPM within reason. The motor probably turns at 3600. I got a windshield wiper motor from a junk car. Direct drive, takes a few minutes to grind 10 pounds of grain. Solar panel charges the battery.

 

[Run4BeerCO]

I might just buy the Malt Muncher Motor. It's $200 but how much will I even save if I try to piece this together myself? I'm really just itching for a project, but building the cabinet might suffice.

https://www.morebeer.com/products/m...uSYth4zFdYCYvIeTDa7SBSHoYt5L49dsaAu7PEALw_wcB

 

[day_trippr]

Well one thing is for certain, you wouldn't have to come up with a way to protect life and limb from what might have been a 40 inch diameter pulley

Cheers!

 

[Golddiggie]

I might just buy the Malt Muncher Motor. It's $200 but how much will I even save if I try to piece this together myself? I'm really just itching for a project, but building the cabinet might suffice.

https://www.morebeer.com/products/m...uSYth4zFdYCYvIeTDa7SBSHoYt5L49dsaAu7PEALw_wcB

I wouldn't look at it as saving $$ but time to get it setup properly. Also time to source the pulleys you need. Plus the shafts to run the interim set of pulleys. Along with the bushing/pillow blocks to mount those pulleys. Not to mention how you need to make sure things are aligned properly so it all spins right. IMO, more hassle than it's worth. Unless you don't have the finances to get the motor and HAVE to go cheapest possible (doesn't sound like it). Design up a nice cabinet for the entire thing to rest in/on and then get to brewing.

 

[day_trippr]

Yeah, I wouldn't want to think about the side-loading the 20:1 reduction needed would put on a mill without a shaft extension and a pillow block to carry the big wheel (and it would be BIG). Mating the mill motor to the mill shouldn't be a big deal, no doubt there'll be plenty of examples to follow. The big thing is getting the shafts vertically aligned; I've had to use different "shims" under mills to get them up to mating height with the motor shafts...

Cheers!

 

[Golddiggie]

Yeah, I wouldn't want to think about the side-loading the 20:1 reduction needed would put on a mill without a shaft extension and a pillow block to carry the big wheel (and it would be BIG). Mating the mill motor to the mill shouldn't be a big deal, no doubt there'll be plenty of examples to follow. The big thing is getting the shafts vertically aligned; I've had to use different "shims" under mills to get them up to mating height with the motor shafts...

Cheers!

With the motor from Monster being really made for their 3 roller mill, I had to make a riser/spacer for my 2 roller mill (circa 2010/11) to get the motor and mill shaft to align. I used some 3/4"x2-1/2" aluminum bar stock (ordered for the project) to do this. I machined the ends of each piece to interlock and then drilled/tapped accordingly (1/4"-28 thread). I had to machine off a little bit once it was fully assembled to get the alignment spot on. Since I have a decent size milling machine, it wasn't that difficult.

I attached the motor to the plate you see in the picture with some simple socket cap screws (had on hand). Just marked the plate, then drilled and tapped the holes. Don't recall if I used any blue Loktite on them or not. I did need to alter the top of the cart that the motor hangs over since the angle iron was a bit too tall for it. Easily done with a right angle grinder. I put the pattern on the aluminum plate as well. Mostly to clean it up. But partially because I like the look. The aluminum plate is a tight fit to the cart, so I don't worry about that. I suppose I could always drill some holes in it later and bolt it together.

 

[Run4BeerCO]

I'm just getting back into homebrewing after having brewed on a 4bbl system for the last four years. My stock pots, carboys, and siphons just don't cut it anymore. I've already spent plenty on pumps, chronicals, and parts for my keggle set up. Another $200 for the motor will hardly be noticed. Hopefully I'm almost done building and can get to the actual brewing finally!