DIY Smooth roller grain mill project. Any tips?

[user 338926]

Many years ago I made 2 grain mills at work. Gave one to my brother and use mine to this day. It's pretty nice, and I see there's complaints on here about commercially available mills which fail to mill properly, and degrade over time it appears. I never had that issue.

I do however want to add gears to synchronize the two rollers, and when I built them, I didn't think to add enough shaft length on which to attach gears to accomplish that. I've sort of considered welding an appendage on... But the shafts are 4140 and would need drawn (stress relieved) in the heat treat oven afterward if I did that. That would create a few other issues with the current rollers which were finish machined after previous welding and stress relief.

So, I have some Schedule 40 steel pipe here that's 6-3/4" OD. I have plenty of the alum frame material I made the original mills from. I do not have enough of the alum sheet metal for the bin, so that's a small issue. but I might have an idea for that. I do not want to buy a sheet of aluminum again, it's a zillion $ a sheet.

So my question is, how many people here have experience with a smooth roller mill with big rollers? I don't even see them sold on the online HBS sites. I suspect that big outfits (breweries) use such animals. I'd need to make really big gears to go along with the rollers, or accept a lot of stress on small ones and a timing belt to cover the rest of the distance between the rollers when the gears are much smaller.

Am I trying to solve an issue that doesn't exist? I notice when I buy pre-milled kits, they are crushed differently than my mill does. There's less powder. Mine absolutely does not have similar speed between the two rollers. It's not as bad as purchased ones I see, but it's not perfect. The idler roller goes slower, which means there's an amount of "grind" taking place vs "crush". We don't want "grind". I do see one mill on Morebeer that has gears for exactly what I want to do. But only one, all the others omit those.

 

[DuncB]

Have a look at this.
https://www.kegland.com.au/products...m-diamond-rollers?_pos=1&_sid=2a4772dfc&_ss=r
I think they used to have the roller as a separate replacement or upgrade as there was a plastic roller I think.
Only one roller powered on this but powering both would be better

 

[user 338926]

Have a look at this.
https://www.kegland.com.au/products...m-diamond-rollers?_pos=1&_sid=2a4772dfc&_ss=rI think they used to have the roller as a separate replacement or upgrade as there was a plastic roller I think.
Only one roller powered on this but powering both would be better

Cool looking gizmo, but that doesn't look even close to the quality of what I have already. Mine will NEVER need the rollers replaced, and I mean never. I'm totally shocked that the majority of the mills sold have knurled rollers to begin with. I mean knurled is ok, but the depth they do is such I can't even do that in my machine shop. That's got to be a beast of a knurling machine. And all to produce a design that's guaranteed to fail.

If they indeed have diamonds on the wheel for traction, why would they need replacements available? My mill has probably done 100+ 10 gallon batches and hasn't changed in operation even 1%. Those rollers are way small also. My mill is probably doing 6-7" of width all at once. More like the width of commercially available mills, but mine actually works.

 

[user 338926]

What I want to accomplish is what they've done here on this Mighty Mill 3. Except, I don't want that third roller. It's not necessary with even the size rollers I have now (3").

 

[user 338926]

Here's a few pictures of the existing Mill I have. As you can see, I didn't leave any shaft sticking out to work with to add gears after the fact.

 

[DuncB]

Here's a few pictures of the existing Mill I have. As you can see, I didn't leave any shaft sticking out to work with to add gears after the fact.

Hi I think the reason they had replacements because originally there were two versions, one with plastic rollers and the other with the metal rollers.

I have been using the metal roller version for a few years now and haven't had an issue or suggestion that they are wearing out and find the crush is very good.

Your rollers look a lot wider than the maltzilla rollers which I suppose are about 30mm wide and diameter about 80 or 90 from memory.

 

[user 338926]

In metric Dimensions yes my rollers are 75 diameter and 150 width. To be more accurate, call it 76 and 152 but you get the idea.

I did look at the tag on the gearbox and it is a 10 to 1 gearbox.

 

[redrocker652002]

Enter BBeerMe as he is the DIY champ in my mind. Dude can make anything out of nothing. BBeerme, where are ya bro? Rock On!!!!!!!!!

 

[user 338926]

I did take videos yesterday doing a .090 crush, but I have to get time to upload them on YT. I took a second video that showed the "slip" of the second roller, and there's less slip than I expected, but it is there. Afterward, I had to re-crush at .080 because again I wasn't thrilled with the crush, so that will undoubtedly slow it even more. What I remembered about timing on my old .105 gap was probably pretty close, but .090 did slow it considerably. I had no choice since thi s bag of Vienna I have has a lot of smaller kernels.

In any case, it took 46 seconds to grind 11.75# at .090. So, precisely a pound every 4 seconds. I also took a shot of the bin with that 11.75# in it and I'd guess between 30-40 pounds would go in the bin all at once. I'll post up the videos sometime after work.

 

[user 338926]

Here's the two videos.

 

[redrocker652002]

Very cool. Looks great. Rock On!!!!!

 

[AlbertaBeer]

So I’m new to the whole grain milling for brewing deal, but I do have large roller mills for feed grain. They only have one driven roller, but are laterally grooved

When they wear out they do exactly what you describe, slip, and the throughput is absolute garbage compared to new or re-cut rollers. I think if I was going to build a mini version I would keep the same design for simplicity sake and stick to laterally grooved rollers to feed product and help transfer power to the other roller

Just curious why youd use a smooth roller, are they more consistent?

 

[DuncB]

So I’m new to the whole grain milling for brewing deal, but I do have large roller mills for feed grain. They only have one driven roller, but are laterally grooved



Just curious why youd use a smooth roller, are they more consistent?

The roller isn't completely smooth it has enough texture to grip the grain and then it gets crushed in the small gap.
Deep gnurling on the rollers would create inconsistency with the engagement of grain between the peaks and troughs of gnurling.

 

[Dave Parry]

I’ve been having exactly the same problem recently and was wondering whether it was because the rollers had got a bit too worn. I read this thread about driving both rollers so tried this solution and it seems to work so far. I haven’t yet used it on a full so will report back. I’ve just used a few rubber seals (the end ones, just keep the others in play, rather than getting too close to the end.)

On my small test runs, it seems to work a treat. I guess overtime the seals may wear and break, but they are cheap to replace compared to the rollers.