What RPM do you run your grain mill at?

[Seabee John]

I just was gifted a 5 HP 3450 RPM motor. I've got a 2" Drive Pulley connected to a 8" Driven pully on a mandrel, which I'll attach to the barley crusher via coupling. The resulting rpm is 862.5 or a .25 reduction

How fast is too fast? I was hoping to keep with the 8", but if I need to, I'll start looking for a 10 or 12"

 

[Misplaced_Canuck]

Personally, I wouldn't run it much faster than 250RPM.

M_C

 

[TXCrash]

850 is a bit fast. Shoot for under 500 rpms.

I crush with a monster mill hooked up to an ancient 500 rpm drill. Crush was acceptable at full speed, its even better with the drill hooked up to a variac (reduces voltage) set to 35%.

 

[wildwest450]

The barley crusher site say's at 500 rpm it yields 6lbs per minute. I wouldn't go any faster than that.


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[michaeltrego]

I used a 1725 RPM dryer motor with my MaltMill. With a 10" sheave on the mill and a 1.5" sheave on the motor, I got the RPM's down to approx 190, and it runs great with a good crush. I would try to keep your RPMs below 300 to avoid pulverizing the grain.



Here is a good calculator to determine resulting RPMs:

http://www.csgnetwork.com/pulleybeltcalc.html

Good luck!

 

[sco999]

I run my Barley Crusher @ 400 rpm. no problems yet.

 

[SDMBREW]

I affixed an old belt driven variable speed drill press to run my malt mill. I found running 500 - 600 rpm sufficient. I have run it up to 1700rpm and the quality of the crush was the same the only fear I have is prematurely ruining the bronze bushings.

 

[Seabee John]

Thanks for all the input. It looks as though I'll have to switch up to the 12 inch pulley in order to get it where it needs to be.

 

[rerobb]

Check McMaster Carr for pullies, they seem to have everything.

 

[Seabee John]

I found a 12" on amazon for 27 bucks... it's the largest I could find with a 5/8" shaft arbor. According to the calculator that should get me down to 578 RPM. That's a little more than I was hoping for, but I think it will do. The only down side I can think of at that RPM would be shredding husks... anything I'm missing?

 

[ClaudiusB]

My mill runs less than 100 RPM and is equipped with a Bodine gear motor.
I paid $5.00 for the motor and $12.00 for the missing cap.
The previous owner had no idea the motor required a cap.


Cheers,
ClaudiusB

 

[Henrythe9th]

I run my Valley mill @177rpm and works great.
my MM MD3 roller mill is @230rpm and I found that at high speeds sometimes the grain will not feed into the rollers like the rollers are spinning to fast and the grain does not get grabbed by the teeth of the rollers.
I would try to get it as low as you can under 300rpm

 

[hrafnkell]

I run my BC at 150rpm - Grain is perfect at that speed, but a tad slow. I run a small homebrew store and 50lb grain bills are not uncommon for customers.

Optimally I would like to run it at about 200rpm but no faster, to keep crush quality top notch.

 

[Bru]

Can someone tell me how I can measure the speed my mill runs at ?

 

[michaeltrego]

Can someone tell me how I can measure the speed my mill runs at ?

To actually measure the speed, you would need some sort of tachometer

To predict the speed, you can use a calculator like this one:

http://www.csgnetwork.com/pulleybeltcalc.html

 

[Seabee John]

So, it's turned out to be more of a monster than I intended, but in the end it's all good. I'll post pics as soon as I get back.

Here's what I got:

3450 RPM 5 HP motor with a 2" pulley

Mandrel with a 4" to 2" step Pulley

Mandrel with an 8" pulley and a coupling to drive the grain mill.

First belt 2" drive (at 3450 rpm) to 4" driven resulting in 1725 RPM

Second Belt 2" drive (at 1725 rpm) to 8" driven resulting in 431.25 RPM operating speed of the mill.

I've yet to run grain through this thing yet, but my guess is that it will work just fine.

 

[sjlammer]

177rpm, with a $40 gear motor. no pulley means no side load on the mill bearings.

 

[wildwest450]

177rpm, with a $40 gear motor. no pulley means no side load on the mill bearings.

I believe i'm going this route, how did you connect them?


_

 

[sjlammer]

I used Spider Couplings from mcmaster.com

6408K11 (buy two... one for each shaft)
6408K84 one of these (the spider)

 

[RDWHAHB]

Where are you getting this $40 gear motor?

 

[sjlammer]

https://www.surpluscenter.com/item.asp?item=5-1098&catname=electric

Boom!

 

[RDWHAHB]

I searched that site & couldn't find. Poor skills here!

 

[RDWHAHB]

I went ahead and ordered one. I like that a lot better than pulleys!
Jeff

 

[wildwest450]

Good stuff sjlammer! Thanks.


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[sjlammer]

My search Fu is strong... Seriously the search engine blows on that site... I typed in "177 rpm gear motor" and "gear motor" Apparently I needed to type in "177.7 rpm gearmotor"

Here is my setup. I used a large project box from radio shack and and on-off-on switch from home depot.

I can try and fund the wiring diagram if you guys have trouble

 

[RDWHAHB]

The motor site has a drawing for the cap.

 

[sjlammer]

Hopefully you see this

 

[Seabee John]

ok, so I had a little time to start building the cabinet... I've got a good portion done. To follow: cut and install the sides, doors, trim. Finish wiring the switch and cord. Build and install the chute for exiting grain and then finish work. Here are some photos of what I've got done so far.

This is the guts:

Top close up of the mandrel crusher connection

a better close up of the coupling

This last one shows how I didn't modify the crusher base, but punched holes to accept the feet and bolts that protrude from the base. I did it this way because I don't actually own the crusher (Nicksteck does) but still wanted a good tight fit with the cabinet.

 

[RDWHAHB]

Looking great!

 

[RDWHAHB]

Got me 177.7RPM! Off to Grainger @ lunch for couplings.
Jeff