The ball mill

[CosmikDebris]

The ball mill

I’d like to manufacture a ball mill. After reading, many posts about this subject it raises more questions then answers.

1) What is the best material to construct the chamber from?
2) Is there any benefit in using a solid rod instead of round balls?
3) How do you keep the product you are milling from gathering at the end plugs or caps?


Maybe a chamber made from 3”x 12” UHMW solid round, bored to 2.5”x11”inside. For the milling media a 1.5” solid stainless steel rod with radius ends.
As for the single end cap, its up in the air.

I plan to use this mill in a metal lathe, chocking the solid end in the lathe chuck and use a live center to apply pressure on the cap or plug at the other end.
Thoughts please.

[Lewis]

I'm fairly sure that there is more than enough info on this site to construct your own ball mill. Or, god forbid, you could try experimenting to see what works the best in ball mills.

I'm feeling nice, so here's all the info wrapped up in a nice bundle, complete with pictures:

http://www.unitednuclear.com/ballmill.htm

I hadn't thought to use solid rod when I built my mill. It seems feasible, but I somehow doubt it'd be anywhere near as efficient as round lead shot.

A word of advice is not to cheap out on bearings, and to add bits of teflon anywhere there is rubbing. Heat is your enemy when milling black powder. It is very annoying to come back to the charred remains of a mill.

[c.Tech]

Static electricity can also be a problem. I remember seeing a ball mill that was made to discharge the static electricity whilst spinning. It would also be a good idea to use a chamber that will generate the least static whilst spinning.

Just in case of an explosion, it would be a good idea to operate your ball mill where the metal balls will hurt nobody if a dust air explosion happens, or place a shield around the ball mill so if it does explode the shield would absorb the shock.

[CosmikDebris]

Thank you for your replies to my recent post, the bill mill.
Lewis, thank you for the link, I have read it before as well as many others, and I’m just looking for a new design. As for the bearings, I agree although they’re not applicable in my application.
c. Tech, The idea of a static discharge system is great, and will be incorporated in the design.

[c.Tech]

If you’re going to make the ball mill it will be great to upload a picture to the forum. Let us know how it goes, thanks in advance.

[jellywerker]

Don't think about buying a United Nuclear mill, they are simply rebranded ones from harbor freight tools. The HFT ones also cost about 50%+ less. I believe they are called rock tumblers on HFT though.

[lucas]

I use 00 buckshot as media. It's fine, but you may try another size. 000 is 30% heavier.

As for design:
a=v^2 / r . You want acceleration to be less than gravity so it tumbles. Maybe 6 m/s/s
g= 9.81 m/s/s

Check your lowest speed on that lathe then calculate the desired radius of the tumbler vessel.

The 1.5" rod for milling media would be a very large size media, with high surface area and probably fine for a large container. It may be too big for a container with a 2.5" dimension.


http://www.thumlerstumbler.com/ these are good

[c.Tech]

lucas, they are good but do you see any mention of the price on the website?

Not displaying the price possibly means they don’t want you to know until you have decided, think about why they would want that.

[CosmikDebris]

Here’s an interesting mixer - ball mill design worth pursuing.

http://www.glenmills.com/product_showcase/index-powder.shtml

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Use the code tag for long URLs. NBK