Author Topic: Grain Mill Speed  (Read 1653 times)

Offline waltsmalt

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Grain Mill Speed
« on: September 02, 2014, 01:29:34 AM »
I motorized my Barley Crusher a couple of years back.  It's worked well, but I'm wondering if the motor is moving too slow.  I think the RPMs are between 60-75 the last time that I checked it.  Is this too slow?  I had a couple of stuck recirculations (RIMS) the last few times I brewed.  Maybe it's just the gap?  Before I widen my gap on my mill, I thought I would ask about what people thought about the mill speed.

Offline klickitat jim

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Re: Grain Mill Speed
« Reply #1 on: September 02, 2014, 04:15:07 AM »
I can't imagine too slow would hurt anything. But mine runs about 250-300 rpm I think.

Offline klickitat jim

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Re: Grain Mill Speed
« Reply #2 on: September 02, 2014, 05:19:24 AM »
I think its something else. It would seem weird that the gap would get narrower all on its own. What else has changed?

Offline duboman

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Re: Grain Mill Speed
« Reply #3 on: September 02, 2014, 11:28:31 AM »
I'm not an engineer but it's my understanding that if the mill is running too fast it will actually pulverize the grain more than at a slower speed, perhaps someone can verify this for me as well.

I use a drill and IME if I run it too fast I get a finer crush than at its slower speed so I suppose that confirms what I stated but it's by no means scientific
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Offline jeffy

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Re: Grain Mill Speed
« Reply #4 on: September 02, 2014, 12:29:08 PM »
My mill goes really slowly because of the gearing ratio I set up with the motor.  It probably goes more slowly than hand cranking and I've never had an issue with efficiency or sticking mash because of that.
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Offline MDixon

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Re: Grain Mill Speed
« Reply #5 on: September 02, 2014, 12:57:55 PM »
The BC page says you can go 500 RPM, but slower should not matter since you can hand crank it. As far as your system and the gap that will be up to you to decide what does and does not work.
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Offline denny

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Re: Grain Mill Speed
« Reply #6 on: September 02, 2014, 02:52:08 PM »
I motorized my Barley Crusher a couple of years back.  It's worked well, but I'm wondering if the motor is moving too slow.  I think the RPMs are between 60-75 the last time that I checked it.  Is this too slow?  I had a couple of stuck recirculations (RIMS) the last few times I brewed.  Maybe it's just the gap?  Before I widen my gap on my mill, I thought I would ask about what people thought about the mill speed.

IIRC, the recommended speed for most mills is around 300 RPM.  Also, I've been told that the faster the rollers spin, the more the shear angle is increased and the finer crush you get.  And stuck runoffs are at least as dependent on your lauter design as the crush.
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Offline waltsmalt

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Re: Grain Mill Speed
« Reply #7 on: September 04, 2014, 12:29:09 AM »
Thanks guys for the feedback.  Going to dial back on the gap for the next go round.  Using a Sanke Keg with a false bottom to mash in (keeps grain off the bottom as I direct fire).  I was initially worried that it was the return manifold that I was using (copper soldered together), but when I switched to a silicone hose lying on top of the grain bed I still had stuck recirculations. 

I'll probably take a belt and suspenders approach and throw in some rice hulls for good measure. 

Thanks again.

Matt