Input on grain mill design

[Hans O. Lowe]

I work for a company doing design, prototyping, and small quantity manufacturing. We've been slow recently and the owner has said a few times we need to diversify. I decided to prototype a heavy-duty grain mill as a possible product to sell. (I don't own one so that's a bonus for me)

If you were adding things to your wish list of what a mill can do and features you'd like to have on one what would they be?

 

[MaxStout]

What's your target market? Just homebrewers, or do you also want to aim for light commercial applications like small breweries, brew stores?

Since you mentioned "heavy duty," I'm thinking you are shooting for one more robust than the typical $100 Barley Crusher, etc.? Maybe do a turnkey thing with built in motor. Ball-bearings for the roller shafts would be nice. If you could pull off a decent mill with a price point less than the $800 SS Brewtech gets for theirs, that could put it within reach of more hobbyists.

 

[day_trippr]

- Frame should be chunky not wimpy
- Gotta be geared
- Hardened rollers
- Quality bearings
- Easily used gap adjusters - that hold their settings!

Cheers!

 

[Hans O. Lowe]

What's your target market?

Anything up to light commercial was my thought.

As drawn now it has 2" rollers with no gears. I planned on case hardening the rollers. It has a sealed bearing on the inside of the drive side.
The rest are foodservice oil impregnated bronze. 3/4" shaft on the drive roller 3/8" on the free rotating one.

I was thinking belt drive, but may consider direct for safety and avoid making guards.

 

[Hans O. Lowe]

- Frame should be chunky not wimpy
- Gotta be geared
- Hardened rollers
- Quality bearings
- Easily used gap adjusters - that hold their settings!

Cheers!

I'd love gears. Gear stock was a little pricey so I thought I'd start without.

Do people want bearings everywhere and forego the bushings?

I do have nice big eccentric dials drawn. Rollers go from 0" to 0.1875" in this iteration.

Thanks for the ideas! Please keep them coming! If you're all interested I can post some screen grabs of the drawings tomorrow.

 

[MaxStout]

Bearings at least on the drive side, especially if you plan to incorporate belt drive (side-loading). The passive roller wouldn't experience the same side-loading. However, another down side of belt drive is the potential liability--you did mention safety. Pinched fingers or getting loose clothing caught in a pulley system would not be good.

Many mills use some kind of screw to set roller gap, often a hex head cap screw. A tool-free thumb screw that can be tightened by hand would be a nice touch.

Whatever fastener you use, make sure the material that you tap threads into is tough enough to not strip out after repeated tightening.

 

[Golddiggie]

Don't go smaller than 2" diameter rollers. If you really want the pro market, you'll want to go for larger diameters (Blichmann's mill has 3" hardened steel rollers).
Have a system that's easy to adjust the gap without feeler gauges. Mark the gap settings in inches, or offer both inches and metric for those who want metric.
If you're going to use bearings instead of bushings, use tapered roller bearings, or at least roller bearings for longevity.
Needs to have a solid motor option that can be purchased at the same time and arrive as a single unit.
If you use aluminum for parts, make sure it's 7075 (not 6061) for strength. Stainless where it matters for aspects.
I wouldn't offer stainless rollers at all. Anyone looking for this level of malt mill won't leave it in a high moisture area when not in use.

 

[WalletHocker]

Reference the Grainfather mill.

Reference the MashMaster mill.

Reference the Ss Grain Mill - Ss Brewtech.

Reference the Speidel MattMill.

Reference the Kegland MaltZilla with Integrated 24v Motor - The Diamond Grain Mill - Standard Diamond Rollers (kegland.com.au)

1. Easy sliding, indexed adjustment
2. Large, narrow slotted rollers 4"+ diameter, 2" width (no diamond coating...) to pull the grain in
3. Easy to clean, non-slipping/clogging
4. Ball bearings
5. Clearly marked and indexed gap settings
6. Motor included option
7. Easy to adjust (clear, visible markings/settings) with a spring-loaded, indexed adjustment that doesn't get in the way of reading the setting.
8. Mills barley, wheat and corn
9. Includes hopper or accommodates an easy to place hopper
10. Quiet (relatively speaking)

What these mills have in common are large diameter, narrow rollers (i.e. 4"+ diameter, 2"+ width), easily indexed gap width adjustment, easy reading of the gap width, no clogging or spinning of the rollers. The problem is each falls *slightly* short in one area.

 

[Hans O. Lowe]

Goodness! Sounds like I need to scrap this drawing and start over!

So, no diamond knurling on the rollers? I can see how it could make flour with a single drive roller, but I would think it help pull grain in without damage on a gear-driven mill. Thoughts on that?

@MaxStout, I will try to come up with a tool-less adjustment. It's a good way to go.

@Golddiggie, No stainless will be offered. It's just too soft for long term. Non 6061 huh? That's all we use here for aluminum. I will look into 7075 and see the cost/benefit. The owner here is cheap so I'm not sure if I can swing it. I was thinking anodized 6061. Is it a threaded hole concern?

@WalletHocker, Thanks for all the links. I will look through this morning and get an idea of where I need to go.

Here's what I drew so far. Looks pretty run-of-the-mill (didn't intend a pun but laughed a bit anyway)

 

[Golddiggie]

7075 has nearly twice the tensile strength of 6061. If you want to get into the segment, going with the stronger material will be a good choice. Personally, I'd select the 7075 option if it was available. I'm actually doing that for a fixture plate for my milling machine. Opting to go with anodized 7075 (also better than raw) and spending about double compared with the 6061 option.

 

[Hans O. Lowe]

7075 has nearly twice the tensile strength of 6061. If you want to get into the segment, going with the stronger material will be a good choice. Personally, I'd select the 7075 option if it was available. I'm actually doing that for a fixture plate for my milling machine. Opting to go with anodized 7075 (also better than raw) and spending about double compared with the 6061 option.

I'm looking into 7075. Looks like it isn't as expensive as I was thinking. Might only account for about $35 - $50 of the cost (before anodizing)

We use this for fixture plates. Nice and flat. Holds threads and dowel holes well.

 

[Golddiggie]

I'm looking into 7075. Looks like it isn't as expensive as I was thinking. Might only account for about $35 - $50 of the cost (before anodizing)

We use this for fixture plates. Nice and flat. Holds threads and dowel holes well.

I'm looking to get the plate, already ready for use, from Saunders (Saunders Machine Works). Already have a cart loaded with the extra goodies to use it fully from the start. Just finalizing how wide it will be. Was thinking 26" to cover the t-slots. Now I'm thinking I'll have it cover to the far right side of the table. So maybe 29-30" wide total. Final 3-4" won't need holes in it.

 

[MaxStout]

Goodness! Sounds like I need to scrap this drawing and start over!

Don't get too overwhelmed with all the responses, or let it divert you too far from your goal. It's just crowdsourcing at this point. Not every element will be practical to what you are designing, and it may not be cost-effective to incorporate everything you'd like.

Perfect is the enemy of good.

 

[Tom R]

I really like the detented gap settings on my Crankandstein 3D.
And the "grain-engaged" gearing works perfectly.

They make higher-end mills than this, but I considered this to be the best value for my use.
3D Homebrewing Mill - $172.00 : Crankandstein , Advancing the Craft

 

[Hans O. Lowe]

Don't get too overwhelmed with all the responses, or let it divert you too far from your goal. It's just crowdsourcing at this point. Not every element will be practical to what you are designing, and it may not be cost-effective to incorporate everything you'd like.

Perfect is the enemy of good.

Thanks for that. I'm going to be limited in my capabilities a bit anyway. I only have a 3 axis mill and an old CNC lathe. I can't cut gears (in a decent amount of time) or mill flutes in rollers. I'll be limited to diamond knurling I'm afraid.

I already received the parts to build the one I have partially drawn. I guess there will be at least one!

I really like the detented gap settings on my Crankandstein 3D.
And the "grain-engaged" gearing works perfectly.

They make higher-end mills than this, but I considered this to be the best value for my use.
3D Homebrewing Mill - $172.00 : Crankandstein , Advancing the Craft

That's interesting. So the grain takes us the space between the gear teeth and there is no contact between the rollers? I wouldn't have thought of that...