Ball mill

[Mike71]

So i have been using a harbor freight ball mill

And have come to the conclusion these things are horrible

I got a washing machine drive unit im thinkinh of makin6a mill out of

Any ideas to help me kick this project off

Thoughts????

[Mike71]

Pic of the drive

[Mumbles]

Open coil motors always worry me for mills. They'll work though. TEFC is always my preference, though still not totally explosion proof.

[PyroPadawan]

I’m with Mumbles on this one, Mike. They’re great, continuous use motors, but being open coil should ask for some concern on your part. Now.....there are ways to protect it. Ie. mount in its own box, couple PC fans pulling filtered (fish tank water filter in a DIY housing) air, locate a far distance from rollers, run v-belt ALwAYS. Bobs your uncle.

[BrentCle]

Hi, I am new to these forums and am looking for a ball mil or DIY ball mill. My purposes are probably different than most people on these forums as I'm looking to use it to grind down MCHA which is freeze dried Bovine powder. I am using it in a DIY tooth powder. My question is, I am looking for advice on something that would be food safe. I am sorry if it is wrong here to ask about different applications than pyrotechnics, but this forum seems to be of the very few that talks about ball mills. The reason I am looking for a ball mill, is because I need the powder to be around 75 microns, preferably less as much as possible. I have looked at food grade options, but all I could find are laboratory jars for planetary ball mils for hundreds of dollars.

Any advice on option would be much appreciated.

[snapper]

a blade style grinder like a bullet might be your only cheap food safe answer, even a decent countertop blender will run you a few hundred

[Mumbles]

The roller portion can be made from whatever you have around. A Harbor Freight Rock Tumbler might do the trick and not cost a ton of money. Stainless steel media would probably work the best for your applications here. I think the trickiest part is going to be finding a suitable food grade milling jar. My first thought is a Curtec drum or bottle, though they're on the larger side generally. They're reported to be food safe, and are a little thicker than most of my other thoughts. They wont last forever though. They're also sort of hard to get in less than case quantities, though I included a link below. You can find them used, but I'd be wary about that for your application. These would be far too big for the aforementioned harbor freight tumbler as well.

 

https://www.curtec.com/en/products/drums/wide-neck-drums

 

https://www.amazon.com/curtec-Drum-Waterproof-6-L/dp/B00HFU5I4G

[Arthur]

First, please consider the regulations in your country/state/county. This could be a food product or a medical product which could change drastically the cost of approved machinery for manufacturing.

 

More you need to consider what material will be abraded from your drum and media and consider what the effect of part per million contamination may be and how to test for it.

[BrentCle]

I think I found an option https://www1.ceramics.nidec-shimpo.com/ball-mill-accessories/ not a bad price. Just have to make a roller that will work with it or find a cheaper option to buy than the ones they make. $1000+... Do you think a harbor freight would run the 1 litre of these? Also would it need a cover over the ceramic so it doesn't slip or would it grip it alright.

Edited July 12, 2020 by BrentCle

[dagabu]

A great milling tumbler: https://www.amazon.com/Thumlers-Tumbler-Heavy-Duty-Rotary/dp/B001NDRT2K

[SnakeJaw]

I am also designing a ball mill for myself, and maybe the progress I've made will help with your design... but I have hit a roadblock and maybe someone on here can help us both.

 

I used the formula:

Optimum RPM= .65 x Critical speed (cascading action of the media stops)

Critical speed = 265.45/sqrt (Jar I.D. - Media O.D.)

with dimensions in inches

And got my Optimum RPM as 73.45

I also found the minimum torque required using the formula:

lbs of container X feet of container radius

I got 9.25 ft lb

Then translated torque and rpm to find minimum horsepower:

HP*5,252/RPM = ft lb

a slight reworking to suit the variables we have...

ftlb * RPM/5,252 = HP

gave me a minimum HP of 0.128, which is roughly 1/8HP

I might want to upgrade in the future to a double can design, so I figured I'd look for 1/4HP motor to future proof.

I found a few that are 1/4HP and TEFC around $100, but the issue I'm running into is all of these motors run at the standard of 1,725RPM. To take 1,725RPM down to 73RPM I need a step down factor of 24.

Which means three step down gears, or in this case, pulleys: a 1:4, then a 1:3, followed by a 1:2.

The 5/8" shaft means minimum 2" pulley on the shaft. So I'd be looking at 2" to 8", then from the 8" shaft, 2" to 6", then from the 6" shaft, 2" to 4", and the main roller will be connected to the 4" pulley.

But all of the designs I've seen around here, including the one for sale on woodysrocks (the upgraded rebel mill), have one single belt and pulley.

To accomplish this RPM drop with one pulley and a 2" starting pulley, I'd need a 48" pulley!!

How are all of you managing this RPM drop from standard high RPM motors?

[Carbon796]

Did did you calculate the reduction from the driven shaft size to drum size ? The drum needs to spin at 73.xxrpm, not the driven shaft.

[SnakeJaw]

Did did you calculate the reduction from the driven shaft size to drum size ? The drum needs to spin at 73.xxrpm, not the driven shaft.

 

That is a very good point, and one I haven't considered yet. Here I am overengineering... lol

 

so a 2" pulley driven by the main motor shaft, to a 4" pulley which drives the drum's 1/2" shaft, to a 6" drum, should get my 24x reduction.

 

Wow...

 

I have been spinnin wheels in the mud on this for 4 days. Thank you for the help!

[SharkWhisperer]

Hi, I am new to these forums and am looking for a ball mil or DIY ball mill. My purposes are probably different than most people on these forums as I'm looking to use it to grind down MCHA which is freeze dried Bovine powder. I am using it in a DIY tooth powder. My question is, I am looking for advice on something that would be food safe. I am sorry if it is wrong here to ask about different applications than pyrotechnics, but this forum seems to be of the very few that talks about ball mills. The reason I am looking for a ball mill, is because I need the powder to be around 75 microns, preferably less as much as possible. I have looked at food grade options, but all I could find are laboratory jars for planetary ball mils for hundreds of dollars.

Any advice on option would be much appreciated.

Why in the world would you ever fathom that brushing your teeth with ground up dried cow bones will be of any benefit to you? You will get zero tooth remineralization from powdered (insoluble) calcium hydroxyapatite (uh, ground bone). It won't fill in holes (caries) to prevent further damage. If anything, its abrasive nature will accelerate loss of your enamel (and then dentin). I've seen this huckleberry supplement marketed for everything from curing arthritis to bad debt and, quite simply, it's bunk. Roast a chicken, dry out the bones after a boil, grind em however you want--voila! Your secret supplement for cheap that doesn't cost $50+ per kilo for a waste product (the slaughterhouse leftovers that the "wellness" suckers don't buy goes into cow/pig/dog/cat/chicken food to up the calcium content--just look for "ground bone meal" in the ingredient list; you'll find it in both dog food and many of the foods you probably already eat regularly). Chicken bones not so different from cow bones (except more collagen on associated tendons, which also is digested back to its primal amino acids before digestion--so, decent protein source). Sheez, call Gwyneth Paltrow and she'll fix you up with some magic crystals that purportedly cure extreme naivety and gullibility. Might save you some $$ in the long run. Or is that where you're buying your magical "MCHA" from?

 

Smarten up, for chrissakes. It's embarrassing watching fellow humans publicly announce their critical thinking defects.

[justvisiting]

An atmosphere conducive to sharing is what makes a forum valuable. Treating people as if they are idiots doesn't seem to align with the best needs of the forum. Nobody wants to be the next guy to be lambasted, so the newbies tend to keep their questions to themselves, and taking risks, rather than being publicly humiliated. Is that what's good for us?

[SharkWhisperer]

Meh. Completely concerned about Newbie pyro safety and willingness to ask questions; not at all interested about gullible wellness wannabes who clearly state their intention, which, as a medical professional, is absolutely deleterious to their health. Might as well brush your teeth with sand, ffs.

 

I highly doubt that any new pyros talking about ball mills are going to learn something by reading about milling cow bones for toothpaste, and doubt they'll be dissuaded by any response to same non-pyro inquiry.

 

Hell, maybe I even inadvertently saved a fellow pyro some teeth, oh my.

[justvisiting]

OK

[BetICouldMake1]

Shark, any knowledge you may have is rendered irrelevant by your generally insufferable attitude. Spare us your armchair pontifications.

[SharkWhisperer]

Shark, any knowledge you may have is rendered irrelevant by your generally insufferable attitude. Spare us your armchair pontifications.

Alrighty, Susan,

 

Thanks much for your insightful post.

[Carbon796]

Shark, any knowledge you may have is rendered irrelevant by your generally insufferable attitude. Spare us your armchair pontifications.

Having google, isn't the same as having knowledge.

[SharkWhisperer]

Having google, isn't the same as having knowledge.

Thanks, Karen,

 

Yet another highly insightful post. Very informative.

[justvisiting]

[MikeL]

Speaking of ball mills

 

Has anyone used this one?

 

https://www.pyrocreations.com/ball-mills-and-media/ball-mill-17-lb.html

[BetICouldMake1]

Many people use that mill or use the jars in a homemade mill. The stock motor on there isn't really enough to run a loaded jar (they hold 35 lbs of lead when properly filled) and it also doesn't turn at the correct rpm without modification.

[MikeL]

I found a modified version, more HP, lower RPM. increased arbor size, twice the price.