Dual roller grain mill question

[heywolfie1015]

Insanely basic question here, but...

I just bought a twin roller grain mill from my LHBS. I have a knob on each side of the mill that allows me to adjust the space between the rollers. If I want to, say, set a 0.05" space, do I set both knobs to 0.05, or do I just set one of them to 0.05? I strongly suspect it is the former, but just wanted to check. Unfortunately, I don't have a feeler gauge at home.

Thanks for any insights.

 

[MonkeyMountain]

Both sides!

 

[billl]

You adjust both. You want the gap uniform all the way across. Otherwise, one side is going to crush finer than the other.

And you really should get a cheap feeler guage. If you dont' have an autoparts store close by, they are only $5 on amazon.

 

[heywolfie1015]

Thanks! Figured as much, but just wanted to confirm. Agreed I really need to get a gauge.

 

[Murphys_Law]

Or you could use a credit card in a pinch! My mill is set to "Amex" at the moment.

 

[Morrey]

Insanely basic question here, but...

I just bought a twin roller grain mill from my LHBS. I have a knob on each side of the mill that allows me to adjust the space between the rollers. If I want to, say, set a 0.05" space, do I set both knobs to 0.05, or do I just set one of them to 0.05? I strongly suspect it is the former, but just wanted to check. Unfortunately, I don't have a feeler gauge at home.

Thanks for any insights.

Agree the feeler gauge route is by far the best. If you by chance do BIAB brewing, you can set your mill gap somewhat tighter than if you do traditional methods such as 3V.

 

[heywolfie1015]

Or you could use a credit card in a pinch! My mill is set to "Amex" at the moment.

Ha! What is the width of an Amex card these days?

My issue is that I use an electric system that requires a coarser grind (around 1.2mm, or 0.048 in.), so I need to make sure it is not too small. Perhaps I need to use multiple credit cards to gauge the distance.

 

[bradleypariah]

Or you could use a credit card in a pinch!

This. In my personal experience, you don't set the gap to the thickness of the card at the edges. I adjusted to the thickness of the card at the raised numbers, and I didn't pinch the rollers down on the card very tight, just slightly touching so I could easily slide the card back out without causing the rollers to move.

The first time, I tried setting the rollers exactly to the thickness of a credit card at the thinnest part, but my rollers spun freely, and no grains fell between them to begin grinding. You're not trying to make flour. Popular opinion is that you're merely trying to break the hull open, or break it exactly in half. Look at the thickness of your grains, mentally cut that thickness in half, then position the rollers maybe a half a millimeter closer together than that. That's about where the grains will get squished enough to get cleaved, without creating a lot of unnecessary powder.

 

[IslandLizard]

0.050" is way too wide.

Using a regular credit card here, the flat part, not the raised numbers. It gives a gap of about 0.034", when there's some friction removing it. Great 80%+ efficiency in a cooler mash tun with batch sparging.

I use a thinner card (0.026") when milling (separately) smaller kernel grain like wheat or rye or flaked corn/rice.

Obviously some flour doesn't scare me.

 

[bradleypariah]

Using a regular credit card here, the flat part, not the raised numbers. It gives a gap of about 0.034", when there's some friction removing it. Great 80%+ efficiency in a cooler mash tun with batch sparging.

I wonder if I have junky rollers. When mine are that close, the rollers just spin freely. No grains get caught in there. Anybody know any tricks to make them more likely to grab?

 

[IslandLizard]

I wonder if I have junky rollers. When mine are that close, the rollers just spin freely. No grains get caught in there. Anybody know any tricks to make them more likely to grab?

A Barley Crusher perhaps? They're notorious for those kind of problems. The knurl may not be sharp enough to "bite" into the grain and pull them down.
Perhaps you could run it through twice, using the narrower gap the second time. See if it makes a positive difference. 0.050" is pretty wide on a 2 roller mill, IMO, not giving you a great mash efficiency.

Do both rollers spin freely when engaged from the bottom, by hand?

 

[bradleypariah]

A Barley Crusher perhaps?

It is!

Do both rollers spin freely when engaged from the bottom, by hand?

No :/ The free roller, or whatever call the one not driven by the drill, doesn't spin without a little coaxing. When grain gets caught, it does spin. I've watched it from the top when the hopper empties. I guess that's the problem I need to solve? I've always thought the roller box was a little misshapen. It's slightly like a parallelogram, and that's what pinches the passive roller.

 

[IslandLizard]

It is!

No :/ The free roller, or whatever call the one not driven by the drill, doesn't spin without a little coaxing. When grain gets caught, it does spin. I've watched it from the top when the hopper empties. I guess that's the problem I need to solve? I've always thought the roller box was a little misshapen. It's slightly like a parallelogram, and that's what pinches the passive roller.

There are more than a few threads dealing with that mill, all having the same thing in common: It doesn't crush!

Misalignment, binding secondary roller, and dull knurls are the most common causes. It should spin freely when jogging it from underneath. Always check that before filling or engaging the mill.

I'd say re-align carefully, leaving a small gap between the roller ends and the side walls and see if it improves. Even my Monster Mill's (MM2) free roller got stuck, being out of alignment, possibly due to over-tightening the bolts on the flimsy MDF baseboard. I realigned and eased up on the bolts a little; it has worked great since. However, I did build a bigger and better baseboard for it too, so it mounts my drill in perfect alignment.